My 2008 Coupe Drag Racing Results Thread [Archive]

Steve M

09-05-2017, 10:36 PM

The purpose of this thread is to document my adventures in taking my Gen 4 Viper to the local drag strip. Yes, there is a 1/4 mile fast list floating around here somewhere, but that thread is pretty dead, and as you'll quickly see, I don't belong anywhere on that list. I also wanted to go into a bit more detail on what exactly has been done to my car along this journey so there will be no doubt about the weather conditions and all of the mods that I've done along the way.

There seems to be a general misconception that drag racing is easy (spoiler alert: it isn't) - after all, we all know bone stock Gen 4s are capable of running a 10 second pass, as seen here:

https://youtu.be/gTevFbLfm3g

...and here:

https://youtu.be/0kp0yjz2jI4

So that means they can all run those kinda times all the time, right? Unfortunately, when you stick an average driver (me) behind the wheel, and top that off with some average track conditions (those runs were done in -1,000 ft DA weather), you end up with a recipe for disappointment. Story of my life, but I digress.

You can't achieve success if you don't even know what you are trying to achieve, so let's start with my personal goals for this car:

1. Run a solid 10 second pass in a full weight car under average weather conditions (low 70s ambient temps, usually good for +2,000 ft DA around here)
2. Trap 130+ in average weather
3. Limit power mods to basic bolt-ons and tuning, but no headers (I have personal reasons for this, but won't get into it here)
4. Drive the car to and from the track, no trailers - I also don't want to touch a wrench while I'm there. If it requires anything more than a tire pressure gauge, it's a no-go.

This car will never set any records, nor do I intend it to. For starters, about the best weather you can hope for around here will get you to around +1,000 ft DA - the track here closes at the end of October, and doesn't start back up until April/May, so any cold and sunny days that are perfect for setting records will pretty much never happen. Basically, I want what I would consider to be a quick, comfortable, reliable street car that I can drive to the track, run some solid times against the local competition, and drive it home. I guess I also want the car to serve as an ambassador for the Viper nation - of the couple times I've been to the track, most of the comments received seem to be some variation of "you just never see Vipers running here." I think the car deserves respect, and I'd like to have some time slips to back that up that are grounded in reality (i.e. not one-off hero runs).

Steve M

09-05-2017, 11:00 PM

Event: Thursday Night Test & Tune
Date: October 13, 2016
Location: Kil-Kare Dragway (Dayton, OH)

This was my first trip to the drag strip in the Viper. It wasn't my first time at a drag strip (I had taken my old Camaro a couple times back in 2004/2005), but it was the first time in a long time, and also my first time at this track. I wasn't expecting much, and that's probably a good thing. The car wasn't stock, so this would have to serve as the baseline going forward. Here are the mods for these 4 runs, broken down by category:

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor (so I could dial in my tune); DSE Heat Shield; DSE Closeout Panel; MCS Shocks
Tires: Michelin Pilot Super Sports on OEM 5-spokes - tires were ~4 years old
Rear Gears: 3.07
Race Weight: 3,630 lbs (I weigh ~240) - the only thing I removed for the runs was the 10" sub I normally keep in the hatch. I had about 1/4 tank of gas at the end of the 4th run when I weighed the car.

So stock exhaust manifolds, stock mufflers, stock clutch, heavy ass wheels, street tires run at regular street pressures (29 psi F/R), etc...basically full street trim.

I ran 4 times that night...the DA's are listed on the time slips, and were pretty decent for this area. I ended up with massive wheel hop on the 1-2 shift for 3 out of the 4 runs. Here was the first (apologies for the crappy quality and camera angles):

https://youtu.be/4My6rCuYT4s

My last pass in the best DA netted the slowest ET and MPH because I short shifted 1-2, and also shifted into 4th before the trap instead of riding out 3rd gear like I had on all the other passes:

https://youtu.be/FCQ-IE_EI8c

And the time slips:

https://image.ibb.co/gHPSuF/13_October_2016_Time_Slips.png

At this point, I realized that coming back on street tires would likely just end up breaking something with the wheel hop...I was relatively happy with the trap speeds, but the 60' times and ET's were pretty pathetic. Like I indicated in the first post, I'm an average driver at best...my shifts are slow, and I can't launch worth a damn. Still, it was fun, and gave me a good baseline to improve upon.

Steve M

09-05-2017, 11:29 PM

Event: Thursday Night Test & Tune
Date: August 24, 2017
Location: Kil-Kare Dragway (Dayton, OH)

Fast forward about a year to round 2. I decided that drag radials would be necessary, so I went through a fair amount of effort to fit an 18" drag radial in the back. Thread about that here:

https://driveviper.com/forums/threads/18591-Forgestar-F14-Wheels-on-my-2008-Viper

While I was at it, I also upgraded the weak axles to some beefier units out of fear that the drag radials would find the next weak link in the drivetrain. Thread about that here:

https://driveviper.com/forums/threads/18997-2008-Viper-CV-Question

I also added a shift light:

https://driveviper.com/forums/threads/17051-gen-4-shift-light?highlight=shift+light

Here are the mods for these 4 runs, broken down by category (differences highlighted):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit
Tires: MT ET Street S/S (345/35/18), set to 20 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.07
Race Weight: 3,650 lbs (I weigh ~240) - again, I removed the 10" subwoofer that I normally tote around. I saved about 30 pounds by going to the Forgestar wheels, but because I had about 3/4 of a tank of gas, I ended up being a little heavier this time around.

So no additional power mods...just some lighter wheels, sticky rubber out back, and some drivetrain upgrades so I didn't grenade anything while trying to get off the line.

I ran 4 times again...the DA's are listed on the time slips, and were on the good side of average for this area. I fixed the wheel hop issue, but still had a hard time getting the car off the line. Here was the best MPH run:

https://youtu.be/JYPEEbmCY1o

My last pass in the best DA netted the best ET, but not the best 60' and MPH because I had some combination of wheel spin and clutch slipping off the line:

https://youtu.be/oR7G2MTyDH8

And the time slips:

https://image.ibb.co/cOXagv/24_August_2017_Time_Slips.png

By the time I finished the last pass, I was smelling some serious clutch cookage. I was on track for my fastest trap speed by the 1000' mark, but given the amount of clutch smell at the end of that run, I'm pretty sure it was the clutch slipping that kept me from getting there. The first run of the night I launched at 4,000 RPMs, and ended up around the 5,500 RPM mark toward the end. Clearly the stock clutch wasn't happy with that, so I guess it is back to the drawing board to see where I go from here.

I doubt I'll make any other runs this year due to work/family commitments, but I at least managed to achieve my goal of trapping 130+ on at least one run. I'd like to be able to back that up with some more runs, but that's going to have to wait until next year. I've got a Gen 5 differential with 3.55s sitting on my work bench ready to install, and I'll mull over the clutch options this winter.

TrackAire

09-06-2017, 02:50 AM

Wow, if you drop the 60' times a couple of tenths you'd be scary!!

Nicely documented, good runs.

Steve M

09-06-2017, 06:13 AM

viperBase1

09-06-2017, 07:54 AM

Intense! N' you make it look so easy. Three gears n' it's over.

I've never gone Trap-ing.. maybe one day.

It seems (to me) like your gears aren't as tall as mine. Must be the 3.55 diff..?

When challenged on the street, the tall gears have been a huge advantage.
I listen to the other guy hit 3rd or 4th before I go to 2nd and pull away. 3rd gear n' I'm gone. :dude3:

Thanks again, another cool thread!

Rocket

09-06-2017, 08:39 AM

Great post - thanks for sharing. Launching these beasts is a real challenge! In looking at your videos, you're fighting the bog vs. tire-spin dilemma. I think it was Ranger that shared his launch technique to get into the 10's. He would start at 3000 - 3500 rpms (might need to go a higher with the dr's) and quickly ride the clutch out while getting on the go-pedal "like you're really not trying to spin the tires". It's that "quickly" part that you need to perfect - to not bog (which looked like was happening in your videos) while not roasting the tires.

Good luck in your quest.

TrackAire

09-06-2017, 10:55 AM

A lot of the "hero" runs you see on the internet are private track rentals only at specific tracks with the best DA and the ability to prep the track exactly how you want it for your vehicles specific launch requirements. Trying to set a record at a Wednesday night bracket race where you have so many different vehicles and tire compounds putting down rubber makes being consistent on the launch very hard. Add to that track prep that is anything but NHRA perfect and it will be hard to hit your best numbers.

Regarding gearing, you have to decide whether you want to be be quick or be fast.....there is a difference.

Redx

09-06-2017, 11:20 AM

Thanks! The car has a 10 second pass in it, but getting it off the line with the 3.07s is asking a bit much of the clutch IMO, which is unfortunate because I like the clutch for everything but this application. I've had a few different aftermarket clutches in my old Camaro, and quickly learned that unless you are willing to pay big bucks for a really nice one, you usually end up with some undesirable traits for a street car. I know 3.55s will help, but I still think even a new stock clutch won't last long with what I'm asking of it. Time will tell I suppose.

3.07's and and a stock clutch are not good. I did a few half mile passes on the stock clutch and it was slipping on the 5th pass. When we pulled the clutch it had a lot of meat but the discs were glazing.

Upgraded to the McLeod RXT and did a 1/4 track day, still on 3.07's, launching at 5000-5500 and cutting 1.6 60's on MT's, hard to get a good launch on the highway gears. Best et was 10.98@129.68, 3800 DA. I have since upgraded to 3.55's and hope to knock a few tenths off.

ViperDC

09-06-2017, 12:51 PM

ViperDC

09-06-2017, 01:16 PM

That shift light is sweet. F1 style. Where did you get that?

Also what short shifter do you have because those throws are super short

Stealth78

09-06-2017, 04:32 PM

Nice runs Steve! I have one of your same issues in regards to the track, they shut down in October, which sucks! I've had my 3:55's for about a month now but unfortunately they are still sitting in a box on the floor at my house along with my GenV intake I just picked up last week. I cannot wait to get the new parts in the car but I've been so busy its been tough. I still need to buy an HP Tuner and get my car dyno tuned once the parts are in.... Not feeling to confident that this is all going to happen before the local tracks shut down for the year. If I can't I may take the car up to the track once just for the shits n' giggles but I know I won't be putting down any record setting 60' times with the 3:07's. Keep kicking ass and also keep us all posted!

Steve M

09-06-2017, 09:20 PM

Intense! N' you make it look so easy. Three gears n' it's over.

It seems (to me) like your gears aren't as tall as mine. Must be the 3.55 diff..?

There are two reasons why I'm able to leave it in 3rd - I bumped the rev limit up to 6,600 RPMs, and the MT Drag Radials are a 28" tire. Unfortunately, it makes launching even harder, but they definitely hook. Bogging on a 5,500 RPM dump told me that the 3.07s are definitely not the right gear for the quarter mile.

Great post - thanks for sharing. Launching these beasts is a real challenge! In looking at your videos, you're fighting the bog vs. tire-spin dilemma. I think it was Ranger that shared his launch technique to get into the 10's. He would start at 3000 - 3500 rpms (might need to go a higher with the dr's) and quickly ride the clutch out while getting on the go-pedal "like you're really not trying to spin the tires". It's that "quickly" part that you need to perfect - to not bog (which looked like was happening in your videos) while not roasting the tires.

I definitely need more seat time...8 total passes in this car isn't enough to figure out what works and what doesn't. Unfortunately, I don't think the stock clutch is going to survive another attempt, so I'll have to see what I can come up with next year.

A lot of the "hero" runs you see on the internet are private track rentals only at specific tracks with the best DA and the ability to prep the track exactly how you want it for your vehicles specific launch requirements. Trying to set a record at a Wednesday night bracket race where you have so many different vehicles and tire compounds putting down rubber makes being consistent on the launch very hard. Add to that track prep that is anything but NHRA perfect and it will be hard to hit your best numbers.

Regarding gearing, you have to decide whether you want to be be quick or be fast.....there is a difference.

The nice thing about this particular track is that it is pretty well prepped for a test and tune type of event. There are usually a couple of fully prepped professional drag cars that end up running, and they don't have too many problems hooking. Both lanes are equally well prepped, and they don't force cars on street tires to only use one lane. Of course, you also have guys dragging water up to the line, but it isn't too bad all considering.

As for the gears, the route I've chosen should make that decision easier. I have an entire new housing set up with 3.55s, so I'll be able to swap back and forth (obviously with some heavy lifting involved) between housings depending on what event I'm doing. For half mile and longer events, the 3.07s will be going back in. I'd probably also use 3.07s for any road racing, if I ever get that itch.

3.07's and and a stock clutch are not good. I did a few half mile passes on the stock clutch and it was slipping on the 5th pass. When we pulled the clutch it had a lot of meat but the discs were glazing.

Upgraded to the McLeod RXT and did a 1/4 track day, still on 3.07's, launching at 5000-5500 and cutting 1.6 60's on MT's, hard to get a good launch on the highway gears. Best et was 10.98@129.68, 3800 DA. I have since upgraded to 3.55's and hope to knock a few tenths off.

I'm expecting to find the same when I eventually take this one out. Your car runs really strong considering that DA...and I thought we had it bad around here. Definitely curious to see how much better you do with 3.55s.

That shift light is sweet. F1 style. Where did you get that?

It's an Ecliptech Shift P2, details here: https://driveviper.com/forums/threads/17051-gen-4-shift-light?p=296461&viewfull=1#post296461

Also what short shifter do you have because those throws are super short

That is the stock shifter with the shorter OEM shift knob that came on the 2010 cars. I think Jon B can still source them.

Nice runs Steve! I have one of your same issues in regards to the track, they shut down in October, which sucks! I've had my 3:55's for about a month now but unfortunately they are still sitting in a box on the floor at my house along with my GenV intake I just picked up last week. I cannot wait to get the new parts in the car but I've been so busy its been tough. I still need to buy an HP Tuner and get my car dyno tuned once the parts are in.... Not feeling to confident that this is all going to happen before the local tracks shut down for the year. If I can't I may take the car up to the track once just for the shits n' giggles but I know I won't be putting down any record setting 60' times with the 3:07's. Keep kicking ass and also keep us all posted!

Good luck...it's taken me a while to iron out all the kinks with mine, but I work slow. I'll be sure to update this thread once I get my clutch situation figured out and get my junk back to the strip.

Stealth78

09-06-2017, 09:31 PM

As for the gears, the route I've chosen should make that decision easier. I have an entire new housing set up with 3.55s, so I'll be able to swap back and forth (obviously with some heavy lifting involved) between housings depending on what event I'm doing. For half mile and longer events, the 3.07s will be going back in. I'd probably also use 3.07s for any road racing, if I ever get that itch.

I agree with you for the half mile with the 3:07's but for anything longer than that I would go back to the 3:55's. I believe 3:55 gears with a 6,600 rpm limit will allow you to hit 201mph in 5th gear.

ViperDC

09-07-2017, 10:38 AM

That is the stock shifter with the shorter OEM shift knob that came on the 2010 cars. I think Jon B can still source them.

Thanks!

Steve M

08-26-2018, 01:00 AM

Event: Thursday Night Test & Tune
Date: August 23, 2018
Location: Kil-Kare Dragway (Dayton, OH)

It's been almost exactly one year later since my last set of runs. I made a couple of big changes to my setup this year, all drivetrain related.

I decided to swap out the stock 3.07s for 3.55s by swapping in an entire new assembly from a Gen 5 - details here:

https://driveviper.com/forums/threads/20084-Gen-5-Differential-in-a-Gen-4

Since the stock clutch wasn't up to the task, I also decided to swap in an Nth Moto Triple Disc Carbon Clutch (I'll finish that install write-up here in the near future):

https://driveviper.com/forums/threads/21571-Nth-Moto-Gen-4-Clutch

Here are the mods for these 3 runs, broken down by category (differences highlighted):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; Nth Moto Triple Disc Carbon Clutch; Moroso Spark Plug Wires
Tires: MT ET Street S/S (345/35/18), set to 20 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: 3,572 lbs - as always, I removed the 10" subwoofer that I normally tote around. The rest of the weight savings came from the following: I swapped out my old battery for a new one that was ~6lbs lighter, the Nth Moto Clutch was 22.5 lbs lighter than the OEM unit, I've lost ~25 lbs since I'm currently training for a half marathon, and the rest was gas (I was around 1/4 tank this time).

So no additional power mods...just gears, a lighter, stronger clutch, and some weight reduction (mostly fuel, some me, and some the clutch).

I ran 3 times this time...the DA's are listed on the time slips, and were similar to last year's. I had one hell of a time trying to figure out the new clutch, and the track shenanigans didn't help much with that one either (note the 3 hour time difference between run #1 and run #2 on the time slips due to people breaking shit on the track). I would start to slip the clutch, but then it would grab hard, so I ended up with this bogging/spinning thing that made for a bit of a wild ride. I also had to add another shift (3-4) with the 3.55s, and my shifting still isn't great. Sadly, the first run was my best run of the night:

https://youtu.be/zwJI-WX5-kY

My next pass was even worse getting off the line, and to top that off, I also missed the 3-4 shift which I've never done in my entire life. Why show it? Two reasons:

1. It's interesting to note just how much speed you lose when you miss a shift
2. I'm all about full disclosure, including my failures. I have nothing to hide...learn from my mistakes so you don't have to make the same ones:

https://youtu.be/0ZMwRZf861k

The car in the left lane was a modded A8 C7Z (E85, ported blower, 19" DRs, etc.) - he let off early on that run, but said he normally traps in the upper 130s, and that the car has gone a 10.3x. Always sad to lose to a Vette, but that was a well-sorted one that ran hard, and the owner was a really nice guy to talk to.

Sadly, my GoPro battery died just before the last run, but the launch was even worse on that run.

The time slips:

https://image.ibb.co/fSiLTU/23_August_2018_Time_Slips.png

So I've learned some things:

1. Getting into the 10s is not going to be as easy as I had hoped - I have new found respect for those that have done it, and made it look easier than it really is.
2. 3.55s help some, but hurt in other ways - my 1/8th mile times and traps this time around were definitely better, but that wasn't translating to anything useful on the big end where I needed it. I'm now crossing the traps at around 5,500-5,600 RPMs instead of closer to redline in 3rd like I was with the 3.07s on my current 28" tires. I'll run these tires for the rest of this year and probably some portion of next year, but the next set of drag radials I get will be a 26" Hoosier which should help get me back closer to peak HP crossing the traps, and hopefully get my traps above 130.
3. Launching with this clutch isn't easy - I'm still trying to find the sweet spot where I can get it to slip at least some, but I need more seat time. 3 hours between passes certainly doesn't help.

At this point, it's time to work on my driving. The car certainly has more than enough power to get into the 10s, but it doesn't have enough driver right now. I'm not sure if I'll be able to get back out to the track this year or not, but I'm going to try my hardest. I'll be sure to update this thread regardless of the outcome.

Stealth78

08-26-2018, 09:33 AM

viperBase1

08-26-2018, 11:10 AM

Thanks for the write up Steve and congrats on all the mods and upgrades you wrenched yourself!

Redx

08-26-2018, 11:19 AM

Steve M

08-26-2018, 12:20 PM

Great write up and thanks for the update. I truly hope you find time to get more passes in this year. My concern is once I get my ass to the track and I run under an 11.49 NHRA is going to require a cage, I believe. How are you getting around this? Is your local track very relaxed with it's rules?

Agree with this assessment:

Do a couple warm ups to get your launch down, then just hit it hard till you get punted. They have the rule here too but haven’t been bothering too many guys unless they are 10.5 and lower.

The only thing they ever get after me about is needing a fire jacket (required for 11.49 or quicker) - notice how a fire jacket magically appeared between my first and second runs?

The track I frequent is a stickler for a couple things, but a cage doesn't appear to be one of them. If you pay very close attention in the second vid, there was a yellow GTR in the left lane that made a pass just before I did my burnout - he ran a 10.2 in the upper 130s. He didn't have a cage, but that's not why they asked him to leave after that pass; he got booted for not having a fire jacket. The dude in the C7Z? His car clearly wasn't stock, and certainly didn't sound stock. He also didn't have a cage, and they left him alone. The newer your car, it seems like the more lenient they are about that particular rule. I don't expect them to really give me much grief if I do get into the 10s about not having one, as long as I have my fire jacket on. If you are on P-Zeros, you likely won't have to worry about any of those rules at all, regardless of how strict the officials are at your track.

My advice: if you are truly worried, just go out there to watch and walk around the staging lanes...chat up the fast guys in late model cars, and ask them about their experience. Chances are that you'll find some regulars that are in the know and can give you a good, honest assessment of the track officials. Most tracks are more interested in the revenue than following the rules to the letter...mine charges $25/car to run at Test & Tune, and there are always tons of cars there, some of which are well into the 10s with no cage. Booting cars on the regular would severely cut into their bottom line IMO.

Thanks for the write up Steve and congrats on all the mods and upgrades you wrenched yourself!

You're welcome...I hope someone is getting at least some useful information out of this. And doing my own wrenching is the only way I can afford to mod this car ;)

TrackAire

08-26-2018, 01:22 PM

I'm not a drag racing expert, but here is what I've concluded from my limited time at the strip.

Most of the hero runs I've seen are usually at a private track rental where you can hot lap if you wish, control your launch and not worry about reaction times, prep the track to your specs, etc. I stopped going to my local Wednesday night bracket racing at Sonoma years ago because you had to "win" your round to advance. Screw up one round and sometimes you'd get as few as 2 runs in one night total (one practice and one bracket race). The crowds are huge which meant even less track time and god forbid if somebody dropped oil or crashed....you'be be sitting in line forever. Sonoma would be warm in the afternoon and downright chilly when the sun went down and the wind picked up. You can't be consistent or get a good run when the track changes temps drastically, car is either too cold or too hot due to waiting, track prep is inconsistent between rounds, etc. It's hard enough to launch our cars in good conditions, but when everything changes every half hour, good luck.

Regarding your clutch, nothing aftermarket that is like an on/off switch is going to work great at a prepped launch pad. IMO finding a very durable organic clutch (maybe even stock) that you can slip the crap out of and just look at it as a consumable part that you'll need to replace every 12 runs or so. Also, figure out how to keep your clutch fluid as cool as possible to keep it consistent for good launches.

My 3.55 gears hurt my 1/4 mile drag times due to extra shifting....maybe a 3.33 with a tire diameter sized to get you through the traps at peak hp in 3rd gear is key for lowest times??

From what I've experienced, it's all in the 60' time when dealing with a high horsepower manual shifted car.....get that perfect and you're on your way to a 10 second run. Looking forward to your next outing.

Steve M

08-26-2018, 01:47 PM

Regarding your clutch, nothing aftermarket that is like an on/off switch is going to work great at a prepped launch pad. IMO finding a very durable organic clutch (maybe even stock) that you can slip the crap out of and just look at it as a consumable part that you'll need to replace every 12 runs or so. Also, figure out how to keep your clutch fluid as cool as possible to keep it consistent for good launches.

That's the weird thing about this particular clutch - on the street, it is one of the smoothest clutches I've ever driven. Once you figure out its slightly lower engagement point, I'd dare say it is even smoother than the stock clutch was, and I'm very picky when it comes to that kinda stuff. You can get the car rolling off idle with absolutely no throttle whatsoever. I know at least one person on this board that's described this clutch as an on/off switch, but that's not been my experience at all, at least not during normal street driving. Could have been an installation issue, could have been a bum clutch...who knows.

Unfortunately, that didn't carry over to the track. I think it is a combination of two things:

1. The hotter the clutch gets, the harder it grabs
2. The unsprung discs - any shock generated goes straight through the drivetrain, making it much more likely to break the tires loose

I might try doing some lower RPM launches to see if it likes that any better. On my first pass, I left around 3,500 or so RPMs, and it netted my best 60' of the night. Trying to launch at 5,000 RPMs seemed to generate more tire spin than forward motion - that's what I tried on my last run, and it netted my worst 60' of the night.

Drag racing might not be this clutch's forte, but it does everything else exceptionally well, and the lighter weight assembly has a huge impact on shifting, throttle response, and how fast the car feels on the street. I'll see if I can get it to do what I want though...might just take some fancy footwork.

Stealth78

08-27-2018, 11:12 AM

Steve M

08-27-2018, 05:48 PM

Where is the best/cheapest place to buy a fire jacket? I'm going to need to get a cheap helmet too as the only helmet I have left with a non-expired date is my bike helmet, which I don't even have a bike anymore but I know bike helmets don't qualify unless you get a clueless tech. This is seemingly going to be a very expensive trip to the track seeing that if I get there this year it will probably only be once.

I went with this fire jacket: https://www.amazon.com/RaceQuip-111006-X-Large-Single-Driving/dp/B004QI1IDU

That's all that's required for 11.49 or quicker.

As for the helmet, I went with a Simpson Bandit...certainly not the cheapest option, but it fits my head well, and looks pretty decent.

This is another one of those "you need to visit your local track" things - every time I've been, they know I need a helmet, and have always asked if I had one. As soon as they see it sitting in the passenger's seat, they don't ask any other questions, and have never looked to see if it is SA2010 or SA2015 rated (mine is SA2015). As long as it doesn't look like a bag of ass, they just assume it's good enough...they don't have time to go over everything with a fine tooth comb. Act like you know what you are doing, and they'll generally assume that you do.

Stealth78

08-31-2018, 07:22 AM

Steve M

08-31-2018, 09:50 PM

Following that link shows me an x-large, assuming that's what you bought. How is the fitment, small, big, just right? Sorry if that sounded a little bit like the three bears. Lol! After losing some weight over the past year or so I have recently found myself juggling between large and x-large. I'd rather not feel tight and restricted but I don't want to be wearing a parachute either. Currently I'm 5'8" about 205lbs.

I used their sizing chart to decide, so I had my wife take a tape to me. I'm usually an XL in most everything I wear, and that seemed to fit their measurement chart. I'd say the jacket ran a bit large for me...I'm not swimming in it or anything, but it certainly isn't tight by any stretch of the imagination. I'm 6'4" and currently around 220.

Steve M

02-24-2019, 06:29 PM

Time for an update on this thread.

I ended up going to two more test and tune events during the 2018 racing season. I'll skip a lot of the details for the first one, and give at least some for the more successful outing back in October.

Steve M

02-24-2019, 06:42 PM

Event: Thursday Night Test & Tune
Date: August 30, 2018
Location: Kil-Kare Dragway (Dayton, OH)

This was exactly one week after my first track outing of 2018. The weather was supposed to be similar. Spoiler alert: it wasn't. It ended up being a decent amount warmer, so DA's were around +2,500 ft, and it was miserable in a helmet, long pants, and a fire jacket. Mods and race weight were damn near identical to the week prior, maybe with an extra 20 lbs or so in fuel. Apparently, it was bring your diesel truck to the drag strip night, so it was a bit of an unusual crowd. One of the built bro-dozers (trailered in on a semi no less) decided to puke oil all over the track after my second run, so I just called it a night after only being there for about an hour.

Neither run was worth a damn, and I must have been pretty pissed because I didn't even keep the time slips. I did record the times though in my spreadsheet:

Run #1: 11.48 @ 127.77, 1.96 60'
Run #2: 12.09 @ 91.04, 1.86 60'

What happened on run #2? I missed 4th gear hard and coasted out the rest of the pass, which was the second time that's happened. I'm starting to suspect worn engine mounts, and also poor technique on the 3-4 shift. After this little fiasco, I decided that doing a full thumb's down, palm facing away hand position would be the best for that shift since I was hitting the gate between 2nd and 4th gears.

This night blew hard. Let's move on.

Steve M

02-24-2019, 07:08 PM

Event: Thursday Night Test & Tune
Date: October 18, 2018
Location: Kil-Kare Dragway (Dayton, OH)

The weather on this day was incredible - it was relatively cold outside, but it was sunny all day. That warmed up the track surface for decent traction, but the DA was hovering around 0 to almost -500 ft at the end of the night. The track went away after the sun went down, so the last 2 of my 6 total passes were a bust, but it was still the best weather I've ever seen in this area while the track was still open.

No changes in mods, no changes in the tune, and probably around 3,600 lbs race weight (I had around 5/8 tank of gas at the start of the night).

Time slips split into two equally shitty pics (I was in the right lane all night long):

https://i.ibb.co/sj96mKj/18-October-2018-Time-Slips-1.jpg

https://i.ibb.co/cgx4g50/18-October-2018-Time-Slips-2.jpg

Run #2 was interesting - I was up against a fairly new automatic Mustang on street tires that had run a high 11 second pass on his first run. By the time I finished the pass, I had missed 3rd gear (hence the low MPH), but I couldn't see him anywhere in my mirrors. As I was getting my time slip, the lady handing them out asked "Are you okay?" I was a bit confused, so I said that I was and asked what had happened. Apparently, the dude lost it, and ended up crossing the center line and spun into the wall. Thankfully, I was out in front, but it was a sobering reminder that things can go wrong in a hurry if you aren't careful. The driver was okay, and probably only sustained a couple grand worth of damage, but damn.

The best run of the night was run #4 just as the sun was going down. Here's a vid of that pass:

https://youtu.be/hA4tGSelDus

So close, yet so far away. Clearly I bogged the launch, and my 2-3 shift was also pretty slow thanks to missing it once earlier in the night. I've found that the biggest contributor to my trap speed is holding onto 3rd gear for as long as possible before shifting to 4th, so I should at least be a little more consistent the next time. Maybe next year?

I'm going to focus on two things for next season:

1. Replacing at least my driver's side motor mount, and probably the trans mount. My shifter moves quite a bit under load, so I'm curious to see what I find.
2. Adding a line lock to get some real heat in the tires. Mickey Thompson recommends just a light burn out for their drag radials, but I don't feel like I'm getting them warm enough to hook consistently. My feet are fairly large, and I'm apparently not coordinated enough to get on the brakes after dumping the clutch. The line lock should help that.

Next year will be the third season on these tires (345/35/18 MT Drag Radials), so they are probably getting a bit past their useful life. I might make a couple more passes on them, or I may just go ahead and switch to the much lighter, much smaller diameter (26") Hoosier drag radials. I'm hoping that will help get my 60' times down, and it should also help with my trap speeds since I'll be crossing the beams a bit higher in the RPM range on the shorter tire. Time will tell...I have quite a few winter projects around the house, so the Viper is currently on the back burner. Spring will be here soon enough I suppose.

ky13

02-24-2019, 08:49 PM

Have you tried preloading with the ebrake on the launch? Nice runs! Will be following along :)

Steve M

02-24-2019, 09:19 PM

Have you tried preloading with the ebrake on the launch? Nice runs! Will be following along :)

I have not. I don't think I'm coordinated enough to do all of that...I'd probably just end up stalling at the line knowing my luck.

viperBase1

02-25-2019, 09:16 AM

Run #2 was interesting - I was up against a fairly new automatic Mustang on street tires that had run a high 11 second pass on his first run. By the time I finished the pass, I had missed 3rd gear (hence the low MPH), but I couldn't see him anywhere in my mirrors. As I was getting my time slip, the lady handing them out asked "Are you okay?" I was a bit confused, so I said that I was and asked what had happened. Apparently, the dude lost it, and ended up crossing the center line and spun into the wall. Thankfully, I was out in front, but it was a sobering reminder that things can go wrong in a hurry if you aren't careful. The driver was okay, and probably only sustained a couple grand worth of damage, but damn.

Whew, close one.
Don't know what to say about Mustangs.. I see 'em sliding off the road in fits all the time.
Drove a 5.0 once on a mountain run and had the sense it was always on the verge of spinning out.. so slowed way down.
Then drove a Carrera 4S on the same road and whoa what a difference.

Glad nobody got hurt on that run and glad you were far enough out front to avoid the whole mess.

Vipes

02-25-2019, 01:21 PM

Nice driving, your car pulls hard! Subscribed!

Steve M

02-28-2019, 01:58 PM

Nice driving, your car pulls hard! Subscribed!

Thanks...it isn't bad for what it is. At the end of the day, it is a 10 second car with an 11 second driver, but I'll get there (just more slowly than most). I still half contemplate eventually adding headers to the mix just to see what difference they would make, but the car does pretty well without them. Maybe if I run across a set of nice used ones...I really hate the Viper tax on some things.

I really think going with the Hoosiers will be a nice change...the smaller diameter itself should help quite a bit, but they are also about 12 pounds lighter each. That's a pretty big difference in rotating mass.

viperBase1

03-01-2019, 09:11 AM

I still half contemplate eventually adding headers to the mix just to see what difference they would make, but the car does pretty well without them. Maybe if I run across a set of nice used ones...I really hate the Viper tax on some things.
Reeeaaaally? Hmmmm. :orange:

Steve M

03-01-2019, 01:07 PM

Reeeaaaally? Hmmmm. :orange:

Yeah...the engineer in me wants to do it for two reasons:

1. A true A to B comparison of what headers actually add to the mix on a stock heads/cam Viper. Since I do my own tuning, I can optimize the tune for each setup, so there would be no guessing what they added (as reflected by the trap speeds).
2. I want to find a good solution to dealing with the heat generated by the headers. That's mostly why I want to buy them used...I'd likely have something like this done to them (http://headershield.com/), and that won't be cheap. Paying for a new set with that on top is too much of a cash outlay for an experiment, at least in my books.

Steve M

02-28-2020, 01:02 PM

Event: Thursday Night Test & Tune
Date: October 17, 2019
Location: Kil-Kare Dragway (Dayton, OH)

Again, it's been almost exactly one year since my last set of runs (18 October 2018). I made one minor change to my setup in 2019: I added a line-lock/roll control. My feet are too big and clumsy in the tight foot well to do a proper brake stand, and I didn't feel like I was getting consistent enough burnouts just dumping the clutch and letting the car immediately roll out. I didn't post a detailed write-up for the line lock install, mainly because it's pretty well documented in some other threads on this forum and a couple others as to how to install one. I chose to wire it with two switches (both mounted next to each other in the center console) for added safety. One is a simple on/off rocker switch that arms the circuit, but does not lock the solenoid. The other switch is a momentary rocker that sends juice through the circuit to energize the solenoid. Both switches have to be in the ON position to lock the solenoid - pushing the momentary switch without the first switch ON would result in nothing. Is it absolutely necessary? No, but I consider it a best practice.

I did do something one-off with the install though that I really enjoyed - my shift light (Ecliptech Shift-P2) allows you to bring in external voltage sources to act as triggers for special warning light sequences. You can see this functionality in the video posted below. At 0:21, you'll see only the far left and right lights flashing - that's warning sequence #1, telling me that the line lock circuit is armed (ON/OFF rocker switch is ON), but not currently engaged (momentary switch OFF). You'll see me fiddle with it (full disclosure: I forgot to pump the brakes before engaging it the first time) for a few seconds, and then at around 0:28 you'll see all the lights start flashing - that's warning sequence #2, telling me that the line lock is engaged (both switches ON), meaning the front brakes are locked down, but the rears are not (i.e. ready to do a burn out). With both switches off, the shift light goes back to functioning like it normally does. It took some thinking and wiring to make it all work, but the cool part was that all that functionality was already built in to the shift light...I just had to make it work.

Everything else remained the same, including the drag radials which are now over 3 years old, and in need of replacement due to the rubber getting a little hard.

Here are the mods for these runs, broken down by category (differences highlighted):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; Nth Moto Triple Disc Carbon Clutch; Moroso Spark Plug Wires; Line Lock
Tires: MT ET Street S/S (345/35/18), set to 20 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,600 lbs - I was around a half tank of gas that night.

So no additional power mods...just one additional supporting mod.

I ran 4 times this time...the DA's were around +700 feet that night, which is really good for this area (track elevation is ~900 feet). The first two runs were complete losses due to the car going into limp mode (cam position sensor error). I didn't get a time slip for the first run due to an error with the timing equipment, but it was likely in the high 11s at 100-ish MPH just like the second run. I was able to clear the codes and reflash the car with a new HPTuners file with the codes disabled to see if I could get it to make a full pass. It did seem to fix the issue temporarily, but I'll have to do some more digging in 2020 to see why it happened (it was on the 3-4 shift both times), and more importantly, if I can get it to do it again. It's never happened before, which is always a bit concerning.

Either way, here are runs 2-4 of that night (note: the time stamps are all 1 hour ahead for some reason):

https://i.ibb.co/cx4sv8g/All-Time-Slips-17-Oct-2019.jpg

Yep, still no 10 second pass, but the car was consistent when it wasn't going into limp mode.

A buddy of mine came to the track that night and was able to get a good video of my last pass of the night, which at least made for a slightly more interesting video than I usually post:

https://youtu.be/A523mJ_FWZI

Again, some more lessons learned:

1. Getting into the 10s with this exact setup is possible, but I'm going to make some more changes to hopefully make it easier next year.
2. Always bring your laptop and HPTuners interface to the track - if I had left them at home, I would have lost the entire night, which was by far the best weather we had that year.

I still need to work on tightening the nut behind the wheel, but next year I'm going to be switching to the Hoosier 335/30/18 drag radial, which is about 2" smaller in diameter than what I was running. I'm hoping this will do two things:

1. Get me off the line better (I tend to bog a lot)
2. Get me through the traps higher in the RPM range, hopefully improving my traps (I'm consistently in the 128-129 range, but I want to be in the low 130s).

I guess we'll see what 2020 has in store.

DEMO MAN

02-28-2020, 01:27 PM

Back In Black

02-28-2020, 01:51 PM

Looks like the nut behind the wheel is doing a pretty good job to me.

Steve M

02-28-2020, 02:15 PM

Nice runs Steve. Just a curious question but would going to a 3.21 or even a 3.07 diff allow you to make the run topping out in 3rd gear and pick up some time savings or would it be lost on the launch?

I've been through the math a LOT, and also have some data on just what you are thinking.

My best trap speed came from running my current drag radial (the 28" MT) with 3.07s. I trapped 130.32 on that run, but my ET was only an 11.41. This was that run:

https://youtu.be/JYPEEbmCY1o

That was damn near a 6,000 RPM clutch dump, and it just bogged off the line. Crossing the traps at nearly 6,600 RPMs was great for my trap speed, but my ET suffered greatly due to how hard it was to get it off the line. And just to be clear, the stock Gen 4 Viper rev limiter is set to 6,400 RPMs - I bumped it to 6,600 RPMs with HPTuners.

I set up an Excel spreadsheet to do the gonkulations if you start messing with the gear ratios. As a note, the tire diameter is calculated as a function of the wheel diameter, width, and aspect ratio, so the MT drag radial comes out as a 27.5" tire, but in practice, it is closer to 28".

Here's 3.07s with the MT drag radials (345/35/18):

https://i.ibb.co/wMhXbdx/3-07-Gears.png

That's pretty much perfect for getting through the traps in 3rd, with it topping out around 135 MPH.

With 3.21s, you'd have to either make the 3-4 shift, or bang off the limiter a bit to make it work due to 3rd topping out around 129 MPH:

https://i.ibb.co/HKhQ9q2/3-21-Gears.png

And with 3.55s like I have now, you can see why my traps are suffering a bit even though my ETs have gotten dramatically better:

https://i.ibb.co/Wts5kzX/3-55-Gears.png

Doing the 3.55s with the 26" Hoosier will not be totally perfect, but most definitely a step back in the right direction:

https://i.ibb.co/kczDBPf/3-55-Gears-with-26-in-Tire.png

By my calculations, I'll be crossing the traps about 400 RPMs higher in the power band - I'm crossing around 5,600 RPMs now, so I'll be around 6,000 RPMs after the tire swap. That might not seem like much, but most Gen 4 Vipers pick up around 20 HP or so from 5,500 to 6,000 RPMs on the dyno. A good rule of thumb is you add about 1 MPH per every 10 HP added, so I'm hoping that my traps will go up 1-2 MPH.

As always, everything sounds great on paper, but things usually happen a bit differently in the real world. That's why I want to get some actual hard numbers backed up with time slips...until then, I'm just another keyboard warrior on the internet.

DEMO MAN

02-28-2020, 02:52 PM

Steve M

02-28-2020, 04:53 PM

You definitely put some serious thought into what it takes to get you into the 10s. I do similar calculations for my distance runs but I don't have to launch hard like you do. My best Gen 4 run in 1/4 was a 11.15 at I think 129 or 130 and that was on street tires. That car had more mods than yours to include headers. You will make that 10 sec run soon I'm sure. On another note my wife is from Xenia so I've been up at Kil-Kare a few times but just as a spectator.

That's impressive on street tires. Best I was able to muster was a few 11.9x runs with tons of wheel hop.

Kil-Kare is a pretty nice track...it is fairly well prepped on test and tune nights, but that doesn't stop all the FWD imports from dragging water up to the line. There's also usually some very interesting cars that show up there...during those last runs, there was a C4 Corvette-based car with no body that was running quad turbos. It looked like someone's science project, but man was it cool looking. Sounded cool too, but I didn't actually get to see it run.

Steve M

02-28-2020, 07:36 PM

There's also usually some very interesting cars that show up there...during those last runs, there was a C4 Corvette-based car with no body that was running quad turbos. It looked like someone's science project, but man was it cool looking. Sounded cool too, but I didn't actually get to see it run.

I realize I'm quoting myself here (and straying way off topic), but I figured the car referenced in my last post (quad-turbo C4) was probably unique enough to be fairly easy to find using some quick Google-fu. And I was right:

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/the-chupacabra-quad-turbo-ls-powered-c4-vette-kart/132398/page6/

Looks like it is most definitely a science project.

Fatboy 18

02-29-2020, 06:21 AM

I've only ever taken mine to the Drag strip once, rolled up to the lights (no prior burnout) Built the revs up to about 2.000, dropped the clutch (Stock), and sheered the LHS Inner UJ Which, in turn smashed the diff Yolk and damaged the end of the Halfshaft!
https://live.staticflickr.com/65535/49006871466_58562d6d59_z.jpg

Expensive day out :(
https://live.staticflickr.com/8227/8586438133_9a3429e657_c.jpg
https://live.staticflickr.com/8107/8587539600_b9bbe39c9e_c.jpg

Steve M

02-29-2020, 11:05 AM

Oh yeah...I did a lot of research when it came to upgrading half shafts and axles, and remember coming across those photos. It didn't seem to matter what you did for the Gen 1/2 half shafts...even the Unitrax ones were known to fail. I guess there's only so much you can do with that design to beef them up.

As I mentioned earlier in this thread, my early build '08 came with the old Gen 3 axles, which were a known weak point. It's hard to not get any wheel hop at the drag strip - if you watch in the video I posted of my run this past October, you can hear it wheel hop initially during my burnout.

I documented my upgrade to The Driveshaft Shop's axles in this thread here:

https://driveviper.com/forums/threads/18997-2008-Viper-CV-Question

I've not worried about them since. This is one of those "an ounce of prevention is worth a pound of cure" instances.

Fatboy 18

03-05-2020, 07:00 PM

That thread link is taking me to replacement oil cooler lines?

Steve M

03-05-2020, 08:37 PM

That thread link is taking me to replacement oil cooler lines?

I grabbed the wrong link...should work now.

Steve M

10-19-2020, 09:55 PM

Event: Thursday Night Test & Tune
Date: September 17, 2020
Location: Kil-Kare Dragway (Dayton, OH)

First time out this year - the weather was decent (about 71°F at the beginning, dropping to around 63°F by my last pass), which resulted in DAs around +2,200ft at the beginning of the night, dropping to around +1,500ft by the end.

My overall configuration was about the same as last year with a couple of minor changes, and one major one.

I finally ended up figuring out why my car was going into limp mode on my last outing of last year - it turned out to be a faulty camshaft position sensor that caused issues over about 6,300 RPMs or so. Details on that one here: https://driveviper.com/forums/threads/26494-Metal-Gen-5-Throttle-Bodies-on-a-Gen-4?p=415225&viewfull=1#post415225 Replacing it fixed the problem, so no more limp mode for now.

I also added a pair of the 2015+ metal throttle bodies, which are slightly larger than the stock plastic ones. Details galore in this thread: https://driveviper.com/forums/threads/26494-Metal-Gen-5-Throttle-Bodies-on-a-Gen-4 If anyone was wondering if they add power, I can now say for certain that they most certainly do not. The only real reason to do it is if you like how they look (and I do, which is one of the reasons why I did it).

The biggest change this year was the different rear tires. For the past 3 years, I've been running the Mickey Thompson ET Street S/S drag radials in a 345/35-18 (28" tire). I decided to switch it up and try the Hoosier DR2 in a 335/30-18 (26" tire) this time around, mostly hoping that it would help get me out of the hole quicker, and through the traps at a higher RPM (hopefully translating into a higher trap speed). Everything sounded great on paper, but sometimes reality just doesn't reflect theory, and that ended up being the case here. I'll get into that more below.

Here are the mods for these runs, broken down by category (differences highlighted):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; Nth Moto Triple Disc Carbon Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies
Tires: Hoosier DR2 (335/30-18), set to 20 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,600 lbs - I was around 5/8 of a tank of gas that night.

I ended up making 4 passes that night, which is about average for a test and tune night around here. I won't bore you with anymore videos at this point (they all kinda look the same), so on to the results:

Pass #1: 11.398 @ 127.77 (1.965 60')
Pass #2: 11.242 @ 127.73 (1.911 60')
Pass #3: 11.417 @ 125.52 (1.817 60') - missed 3rd gear
Pass #4: 11.272 @ 128.57 (1.928 60')

Mediocrity strikes again.

I just could not figure these new tires out for the life of me. The Mickeys required very little in the way of a burnout...I usually just cleaned them off with a bit of a first gear burnout, and that was good enough (and what the manufacturer recommended). I tried the same with the Hoosiers, but no dice as you can see by the piss poor 60' times. Thankfully, one of the veterans that frequents this track took an interest in my misfortune, and gave me some good pointers. He ended up watching the 1st and 2nd pass, and noticed that I wasn't getting enough heat in the tires during my burnout (no smoke). That was pretty evident as I rolled back into the staging lanes after a pass - the Mickeys would be covered with little rocks, but these things were totally clean. He suggested giving them a good 5 count before rolling out to see if that would help. On the third pass, I did exactly that, but then I ended up missing 3rd gear, trashing that run (the 60' time was better though). By the time I got to my 4th pass, the track started to go away as is usually the case after the sun goes down and the humidity goes way up.

So nothing spectacular, and certainly not even close to a 10 second pass on this night. I was hoping the shorter tire would equate to a 1-2 MPH increase on the big end, but that just didn't materialize. The DA wasn't as good as it has been in my past outings, but I still thought I should have seen something. So much for my theory.

Maybe next time...

Steve M

10-19-2020, 10:15 PM

Event: Thursday Night Test & Tune
Date: September 24, 2020
Location: Kil-Kare Dragway (Dayton, OH)

I decided I needed more seat time, weather be damned. I normally don't like running when it is warmer out - a helmet, a fire jacket, and jeans aren't exactly the coolest things to be wearing in the heat and humidity, but sometimes you just have to play the cards you're dealt. It wasn't hateful, but the first pass was around 80°F as measured by a Kestrel 5100 weather meter (new toy). With the humidity and pressure, that gave me a DA of 2,517ft for the first pass (track altitude is around 800ft or so according to some online sources).

Here are the mods for these runs, broken down by category (no differences):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; Nth Moto Triple Disc Carbon Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies
Tires: Hoosier DR2 (335/30-18), set to 20 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,600 lbs - I was around 1/2 of a tank of gas that night.

I ended up making 2 passes that night spaced almost two hours apart, which is just shitty. Everyone was breaking shit that night and oiling/watering down the lanes even before my first pass, and it never got any better. The results:

Pass #1: 11.309 @ 127.88 (1.925 60')
Pass #2: 11.164 @ 128.21 (1.821 60')

These mother f-ing tires.

This time for my burnouts, I wasn't screwing around. I've never done a 2nd gear burnout, but on that night I wasn't taking any chances on not getting enough heat in the tires. As soon as I dropped the hammer, they went up in smoke, but it didn't make a damn bit of difference on that first pass, likely due whoever watered/oiled down the right hand lane prior to my getting up there. No one hooked up on that first pass - I asked. I did the same burnout (2nd gear for a good 4-5 seconds) on the second pass, but I ended up bogging out of the hole (I launched around 4,000 RPMs or so). Spin or bog, I just can't seem to find a good middle ground.

I also can't seem to find any extra MPH anywhere, but I may know why after thinking about it some more. In the process of dealing with my limp mode issues and tuning the 2015+ throttle bodies to work on my car, I added a bit of fuel at WOT and tweaked a few other things along the way (I was pretty desperate to figure it out). Way too many changes to get a true A-B comparison from my runs the previous years on the taller tire, so I've since gone back and changed pretty much everything in the tune back to the way it was just so I can get a good baseline whenever I get another chance to run. We'll see if that makes any difference.

The night was still pretty fun though...definitely some cool cars there, including the guy behind me in an Audi S7. I know it wasn't stock (I overheard him saying he added some bits from the RS7 to his setup), but man, what a sweet car. Huge 4 door car that ended up running a 10.9x on his last pass on street tires. Cool guy too...big props to him on a well done setup that can drive to/from the track, AND haul the family around.

Steve M

10-19-2020, 10:52 PM

So I've had a lot of time over the past few weeks to really think about my drag racing results over the past few years. I've wanted to get back out to the track, but so far I've been greeted with two rain-outs, and one night where they were only allowing cars with slicks to run due to a big event they were having that weekend. That one really pissed me off because the weather was perfect (low 60s).

I've made a total of 29 passes dating back to October 2016. Here is a table with all of my results:

https://i.ibb.co/5K3k0bh/All-Passes-to-Date.png

I've been looking at these numbers for a long time trying to make sense out of them, but no patterns stick out - they all seem pretty random. As an engineer, that really bothers me.

There's a general rule of thumb that cutting a tenth of a second off your 60' time equals about two-tenths off of your quarter mile elapsed time. On a whim, I decided to apply that as a correction to my existing numbers to see what happens. The equation goes like this:

Projected e.t. = Actual e.t. - 2*(Actual 60' - Projected 60')

As an example, if a 1.9 second 60' time netted you an 11.60 elapsed time, and you wanted to know what you would have run if you could cut a 1.8 second 60' time, you put it in the equation and come out with an 11.40 projected elapsed time. Again, it is a rule of thumb, not a guarantee. After all, there are 5 things I have to get right on any given pass:

1. The burnout (especially important with the Hoosiers in my recent experience)
2. The launch (still have yet to get that one right)
3. 1-2 shift
4. 2-3 shift (missed that one a couple of times)
5. 3-4 shift (missed that one a couple of times)

But when you apply the math to my existing runs, everything kinda falls in place:

https://i.ibb.co/Y29sS4X/Projected-Runs.png

My actual runs are on the left hand side - everything to the right of the big black divider down the middle is a projected time if my 60' time had been better. The ones that are greyed out I ignored due to missing a gear on those runs.

Based on that, it looks like I should theoretically be able to get a decent 10 second pass if I can just get my 60' time down to a 1.70-1.75 with my current setup, which I feel is a modest goal given what I've seen others run on these tires. Things start looking really good if I can get down in the 1.6x region, but I won't hold my breath. These cars are just so hard to get off the line cleanly, especially when you only get a handful of runs each year, with anywhere from 30 minutes to 2 hours between runs.

I'm hoping the weather forecast holds for this Thursday - it looks like it is supposed to be sunny and 79°F, so it should be very similar to my last outing on September 24th. If they are running, I'll be there to see if I can at least add some more data to my spreadsheet. I still very much want that elusive 10 second time slip...

Patentlaw

10-20-2020, 02:58 AM

Hi Steve,

So I like the engineering challenge. First, I think you have really analyzed everything well. One thing I noticed and that is really basic, is that you have a tendency to run better times with the temperature right around 50 degrees. The outlier is 8/23 where you were driving really effectively based on your 1/4 mile time and there being a 20 degree temperature increase, but only a very mild increase in time. I think that you were just "on" that day compared with the others. That type of driving on a colder day and I think you have it. No further analysis needed.

One thing I don't see is the amount of gas you had. At 6lb per gallon, perhaps some of your variability is based upon the amount of fuel in the car. I know.....the last thing you need is another variable, but it is a possibility. 6 gallons is 36 pounds. Just roughly calculating, that is 1 percent difference which would be enough to put you under.

Another variable that may come into play even more is the coefficient of friction for rubber at different temperatures. There have been a few studies that I saw on the internet looking at the differences between 30 degrees to 85 degrees. Seeing as the temperature really played a factor there, something as simple as warming the tires and a few seconds could make all the difference as the tires will hook up better. Again, not perfect, but we are talking such small amounts here, that any of these factors can come into play.

Plaw

Steve M

10-20-2020, 11:27 AM

Yes, the density altitude and race weight will both have an impact, but I've largely avoided factoring them in for a couple of reasons:

1. Up until now, I've had to rely on online resources for the density altitude at my local track. It always seems reasonable, but I've noted enough discrepancies between what the databases say and what I've observed at the track to know they aren't 100% accurate. Having my own weather meter from now on will help, but unfortunately the vast majority of my data was generated without it.
2. There is a scale at the track - sometimes it is working, but sometimes it isn't. I've only used it a couple of times to get a general idea of where I sit, and it's always been right around 3,600 pounds give or take. Getting a race weight after every run is possible, but it takes up valuable time, and is also a bit cumbersome because it is the same guy running that along with handing out time slips to all of the people running (which is usually about 100 cars on any given night).

I tend to show up to the track in about the same general state every time - full street trim, about 1/2 a tank of gas for the first pass, and all of my typical equipment (GoPro, laptop w/ my tuning interface, tire pressure gauge, helmet, fire jacket, and usually a couple bottles of water and some light snacks). The car gets driven to and from the track exactly like I race it, because 9 times out of 10 I'm completely on my own. My race weight has probably gone down by about 60-70 pounds over the last 4 years I've been doing this...I've personally lost some weight due to long distance running, and I've also shed some vehicle weight with the lighter weight Nth Moto clutch assembly and the lighter wheels and tires. There was about a 10 pound difference per tire just between the Mickey Thompson drag radials and the Hoosiers I'm running now, which also has the added benefit of being rotational mass - some say a reduction in rotating mass is worth way more than just removing seats/carpet/etc., but how much is debatable. That's why I was expecting to see at least something in the form of better MPH with the Hoosiers, but then I had to go and mess with the tune.

The weather is always a wild card, especially around here during the month of October when I've run my best times. It could be 80°F, or it could be 50°F on any given day. I also don't really pay attention to other factors like wind speed or direction; the track faces northwest, so any wind will generally be a head wind, but it's never usually any more than 5-10 MPH. I also don't have any idea what the track surface temps are like. So yes, my best results do tend to be when the air temps are under 60°F, but those days have also usually been sunny, so the black track surface will be quite a bit warmer than if it was cloudy. The one thing I've noted is that most people tend to make record breaking passes when the temps are low, but the sky is clear. Cool air + a warm track due to the sun is a pretty good recipe for making power and being able to put it down effectively. Unfortunately, getting those awesome conditions around here that just so happens to also be on a Thursday night when the track is open is rare. This Thursday is looking like it'll be in the +2,000ft DA region, which will be very similar to the two nights I've run so far this year. Good for an A-B comparison, but unless I drastically improve my driving, I'm guessing I'll have another handful of 11-second time slips.

I've seen the general rule of thumb that for every 100 pounds you lose in race weight, you improve your e.t. by about 0.1 seconds. I've also seen people correct for the density altitude - that one is somewhere between 0.08-0.1 seconds improvement for every 1,000ft decrease in DA. Again, it all sounds good on paper, and would maybe make me feel a little better about what the car could run, but at the end of the day, I can only show my time slips as proof of my accomplishments, and those ain't changing. Yes, the one to two tenths I need to get into the 10s could probably be accounted for with those two factors alone, but the 60' times are where I stand to benefit the most by far in my estimation.

The more I do this, the more respect I have for anyone that can pilot a manual car into the 10s. Some even make it look easy, but apparently I'm just not one of those guys. My response to anyone that asks "what does it run" when I'm at the track usually gets something along the lines of "It is a 10-second car with an 11-second driver."

Patentlaw

10-20-2020, 04:13 PM

I think you are being too hard on yourself. It is a rare bird that can actually drive a car to the maximum potential. And, generally, for those that do, mechanical problems are usually encountered. That being said, I would agree that working on your launch is the best solution to the issues that you present. It presents the biggest source of error. Really when you look at it, after the shifting, it is all just physics. Not much you can change.

Since you went into such great detail on the analysis, I just wanted to put in my two cents to get that "perfect" run. I am anticipating that others will pull up this thread in the future and it will be a treasure trove of "this is how you do it" to get to 10.

Heck....on a different prepared track, you could be well into the 10's and you would be "proud" of what you accomplished. Just that factor alone can make the difference.

These are the threads that make this website worth while.........people can see and build off of the experience.

Steve M

10-20-2020, 04:32 PM

I will not argue on being hard on myself, sometimes to an unhealthy level. I think my frustration is compounded by my relative lack of access to the track itself, outside of paying $5k+ for a private track rental.

I will say that the car itself, with what's been done to it, has been 100% reliable - the possibility of breaking something never really crosses my mind anymore when it's go-time. The upgraded axles and the Nth Moto clutch have never skipped a beat. I'm sure my missed shifts have not done the transmission any favors, but it has taken the beatings without issue to date. I'm sure I will end up having to look at a rebuild over the next few years if I keep this up, but I'll cross that bridge when I get to it.

I'd never personally recommend a Viper for drag racing - there are way cheaper options to go faster, easier. But there's something cool about being the only one there at the track, and receiving pretty much universal praise for even attempting to do something other than just letting it rot in my garage. There's a lot of Viper fans out there of all ages - even some younger kids know exactly what it is. That's what keeps me coming back for more.

viperBase1

10-20-2020, 04:40 PM

Maybe try the TKO ThrottleMax in the mix.
I think its done wonders for my launches and smoothed out my shifts.

RT SERPENT

10-20-2020, 04:55 PM

Steve M

10-24-2020, 12:11 AM

Event: Thursday Night Test & Tune
Date: October 22, 2020
Location: Kil-Kare Dragway (Dayton, OH)

The highlights:
- Got a new personal best, but still not a 10 second pass
- Weather was not great; it was warm, and really humid towards the end of the night (88%)
- Found my missing HP; as suspected, it was in the tune. I reverted back to the old tune from 2019 - my traps went up even in the not-so-great air, which is what I thought should have happened with the Hoosiers
- Track prep was exceptionally good - they had a private rental earlier that day. It was better than I've ever seen it, but unfortunately I was not able to take advantage of it.
- I was full street trim, including my subwoofer (+30 pounds). I got tired of not being able to listen to decent music on my way to/from the track. It probably cost me my 10-second time slip.

As always, my mods with differences highlighted:

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (reverted back to my 2019 tune)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; Nth Moto Triple Disc Carbon Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies
Tires: Hoosier DR2 (335/30-18), set to 20 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,600+ lbs - I was around 5/8 of a tank of gas that night.

I ended up making 3 passes total. The results (right lane for all 3):

https://i.ibb.co/M2pSwGm/22-October-2020-Time-Slips.jpg

My 2nd pass was the best race I've ever had, and was my best pass to date (even with the crappy DA). It also happened to be against a cool car - a 2012 McLaren MP4-12C. Earlier this evening, I stumbled across the YouTube video someone shot at the track last night (my race starts at 1:37):

https://youtu.be/skjolvKFRyM

The McLaren got the win light by .0349 seconds, but it was a damn good race. I'll have to upload my GoPro footage when I get a chance so you can see what I was doing in the Viper, which pretty much amounted to losing ground on each shift as I expected would happen against a dual-clutch equipped car.

As you can tell from the trap speeds on the slip, he clearly has the faster car. He did not use launch control, and he was totally stock on street tires. If he had used launch control, I would have been chasing him rather than what happened - him chasing me down at the end. The guy was really cool, and had only owned the car for 5 weeks. He's the one that suggested the race, so we made it happen. The 570S you see at the beginning of the video was running somewhere in the 10s @ 137 according to the driver (it was tuned).

All in all, it was a great night - the race with the McLaren made my whole year. Which is good, because next Thursday night is the last night for test and tune this year, and it looks like it is gonna rain. Maybe next year...

I'll update this thread when I get my GoPro footage edited.

Steve M

10-24-2020, 09:06 PM

The same guy caught my 3 runs from last October, and the 3 runs from the other night and put it all in one video:

https://youtu.be/H9XyJxhOj8g

You can see the car go into limp mode on the first race against the blue Corvette due to the camshaft position sensor issue I was having last fall. I still have all the GoPro footage from all of these runs, just never edited them. Much more interesting watching the car from the outside.

Steve M

12-17-2020, 01:16 AM

It's winter, and I'm bored, which means it is time for me to organize all of the data I've gathered over the past year into something that's easier to digest. I like spreadsheets (I have a lot of them), and I have the time, so why not make one more? This time, I decided to focus on density altitude.

Earlier this year I bought a Kestrel 5100 handheld weather meter so I could directly measure density altitude at the track. While not cheap, it seems to be the standard for being able to get quick, accurate density altitude data. It's really only important if you are a serious racer (i.e. not me), so while it was probably not the wisest decision, what's done is done.

I only had it for my last two outings to the track this past year, but I was able to use it to gather data from 5 different passes on 2 different nights. Out of curiosity, I decided to compare the readings to a couple of the more well-known websites that gather and archive density altitude data for tracks around the country:

DragTimes - http://www.dragtimes.com/da-density-altitude-calculator.php

Air Density Online - https://airdensityonline.com/us-track-list/

DragTimes has archived weather data dating back to 2015; Air Density Online has archived data back to 2016. I've always considered the DragTimes database to be the gold standard, as it is the one you see most often quoted on different forums. It is also the database behind most of my DA data for the 32 passes I've made to date at my local drag strip over the past few years.

So how accurate are those databases compared to the Kestrel 5100? Sometimes pretty close, but other times not even in the same ballpark:

https://i.ibb.co/DMsJ88P/Density-Altitude-Data.png

My Kestrel (truth source) readings are in red, DragTimes archived data from the same date/time in blue, and Air Density Online data in green. I wouldn't expect them to be identical, but some of them are way off, upwards of 500-600 feet compared to the Kestrel readings. On average, the DragTimes data was better - averaged over the 5 data points, it was 169 feet off. The Air Density Online data was around 287 feet off. Clearly 5 data points isn't enough to assess trends, but still, I didn't expect them to be that far off. After some poking around, I've seen others claim that online databases can be off by as much as 1,000 feet...now I can see why.

As a general rule of thumb, every drop of 1,000 feet in density altitude is good for about 0.1 seconds off your elapsed time and about +1 MPH added to your trap speed (it's rough, but close). As a reference, people that run record times generally run in negative DA conditions (a.k.a. mineshaft air), sometimes as low as -1,000 feet, possibly lower. Average conditions at my local track during the driving season will put you around +2,500 feet; a good night will be around +1,000 feet; a great night (rare while the track is still open) will be down close to 0.

What is Density Altitude (DA), and why does it matter?

Before this, I couldn't really answer that question. That led to hours of reading through some very dry documents while trying to piece everything together. I'll try to summarize what I learned so you don't have to spend hours retracing my steps.

Density altitude is a function of the track's elevation, the barometric pressure, the ambient air temperature, and the humidity. It is not the actual altitude, but rather an apparent altitude adjusted for the variables listed. The lower the density altitude (denser air), the more power your engine can make (i.e. low DA = good). Each variable's effect on the density altitude is fairly intuitive, except for the last one (at least for me):

1. Lower elevation = lower DA (makes sense)
2. Higher barometric pressure = lower DA (sure)
3. Lower temperature = lower DA (check)
4. Higher humidity = higher DA (as in, less dense - say what now?)

I've always felt that really humid air seems thicker (at least when I'm running in it), but the opposite is actually true. Don't think about it too hard; just press the "I Believe" button and move on with your day.

So now we need a reference. People often like to correct their numbers (horsepower, e.t., or trap speed) back to a "standard day" just to make it easier to compare apples-to-apples. There's an international standard day definition that's captured in ISO 2533:1975, but I didn't feel like paying $185+ to read it. The US Standard Atmosphere definition, published by NASA in 1976, was a little easier to come by (https://ntrs.nasa.gov/api/citations/19770009539/downloads/19770009539.pdf). The relevant values for a standard day from that document are listed below:

1. Elevation = 0 feet (sea level)
2. Barometric Pressure = 29.92 in Hg (inches of Mercury)
3. Temperature = 59°F
4. Humidity = 0%

Barometric pressure can be a bit tricky, so be careful. The barometric pressure you see reported in your standard weather feed is actually a corrected value as if it was measured at sea level. You can read more about that here: https://www.weather.gov/bou/pressure_definitions As I'm writing this, the corrected (mean sea level) barometric pressure in Dayton is 29.94 in Hg. The uncorrected or "station pressure" value where my house actually sits (@ 986 ft elevation) is 28.89 in Hg. Most online weather databases report barometric pressure values corrected to mean sea level, but devices like the Kestrel 5100 report the pressure uncorrected, so keep that in mind. Also keep in mind that pressure when measured in inches of Mercury changes with the ambient air temperature (it goes up as temperature goes up, and vice versa).

So why are the online databases so different from each other, and why don't either match up all that well with measured data from my handheld weather meter at the track? There are a couple of reasons.

First, the two databases don't agree on the track elevation. Air Density Online reports a track elevation for Kil-Kare of 803.8 feet. DragTimes says it is 910 feet. Which one is correct? Technically neither...the US Geological Survey database (https://viewer.nationalmap.gov/theme/elevation/) says it is 813.13 feet. In this case, Air Density Online is closer, and is just on the edge of the error bounds of the USGS data (~10 feet). I'm not sure where DragTimes gets their elevation data, but it isn't even close. I checked a couple of other tracks around the country, and the elevation numbers were much closer among the three sources, so that problem could be unique to Kil-Kare.

The larger issue is that both databases gather weather conditions from weather stations that are likely not even remotely close to the track. How far away they are is anyone's guess...I couldn't figure it out, and I'm not even sure the folks that own those websites would be able to tell me. DragTimes says their data is "obtained from an airport near the track", but does not specify which one that might be. Air Density Online gets their data from Dark Sky, which does not reveal sources. The temporal resolution of the data for each site is also only in one hour increments, so if you make a pass around 7:30PM, your actual DA value is going to be somewhere between the 7PM and 8PM readings, further complicating things.

Bottom line: if you really want to be able to compare your runs at the drag strip to others, especially if they are on different days and at different tracks, you need to know the density altitudes at the times/places when each pass was made. If you are relying on an online database for that information, it could be way off. Based on what I've seen from my own DA data (most of which is from online sources), I can't even really compare the different passes for my own car.

Even if you have the actual DAs, I'd still take it with a grain of salt...if you want to have a pee pee measuring contest with time slips, you really just need to just line 'em up and see who comes out on top. Anything else is pure conjecture.

Steve M

03-14-2021, 11:31 PM

Finally got around to editing the in-car footage of the race vs. the McLaren MP4-12C:

https://youtu.be/iRYZ7AlhKH4

J TNT

03-15-2021, 07:35 AM

Nice run Steve , and impressive seeing a stick car faster than a McLaren...

Gen3CoupeTX

03-15-2021, 09:53 AM

This a cool thread. Seeing that 11.02 time slip tells you there's a 10 in there. I know Steve won't let up on himself, but there's also a 10 second driver in the mix!

Shifting gears a bit, some pun intended, I only took mine to the track once. The fastest time it ran was my first one. The next two were slower, and I drove home.

I know me > If I start chasing something, I'm not going to stop. I sometimes (not always) regret the money it consumed. Steve is on a mission, and I respect that!

98intrigue

03-15-2021, 04:56 PM

Any more runs since October? Another few hundreds off of that 60' and your 10-second pass is there.

Steve M

03-15-2021, 07:05 PM

Nice run Steve , and impressive seeing a stick car faster than a McLaren...

Thanks...I didn't know anything about the MP4-12C before hand, but I had at least seen his first pass so I knew it would be a pretty even match. Pretty sure he would put 1-2 car lengths on me from a roll on the street based on what he was trapping.

This a cool thread. Seeing that 11.02 time slip tells you there's a 10 in there. I know Steve won't let up on himself, but there's also a 10 second driver in the mix!

Shifting gears a bit, some pun intended, I only took mine to the track once. The fastest time it ran was my first one. The next two were slower, and I drove home.

I know me > If I start chasing something, I'm not going to stop. I sometimes (not always) regret the money it consumed. Steve is on a mission, and I respect that!

I'm not short on ideas to get there...I already added an underdrive pulley back in November after the track had closed down. The tune is pretty spot on, but I might try to find a few more tweaks this year...at this point, I'm splitting hairs with this setup. The car clearly makes enough power to get there...just gotta get it off the line better. I have a couple ideas there as well.

Any more runs since October? Another few hundreds off of that 60' and your 10-second pass is there.

Unfortunately not...that ended up being the last test and tune of the season up here. The earliest the track will reopen this spring might be sometime in April, but the weather around here usually ends up being a craps shoot until May.

Vipervin

03-24-2021, 08:31 PM

This is a great thread. It's rare to see someone provide such great documentation of their experience modding...especially over an extended period of time. Very helpful.

Steve M

03-24-2021, 10:07 PM

I'm glad you find it helpful...sometimes I go back and read through everything just to remember the journey.

I swore to myself I wouldn't mod this car to the point where it was no longer fun to drive. It happened with my last car, and it really took the joy out of driving.

I even sorta remember the conversation I had with my wife right before I bought this car:

Her: And you aren't going to want to mod this one?
Me: Absolutely not. This car is perfect just the way it is.
Her: Are you sure?
Me: Oh yes...I won't make the same mistake twice.

Obviously I didn't hold up my end of the bargain, but I have a very understanding wife. It's a slippery slope, but I do try to keep it reined in. Sometimes.

Steve M

10-10-2021, 12:09 AM

Event: Thursday Night Test & Tune
Date: September 9, 2021
Location: Kil-Kare Dragway (Dayton, OH)

The highlights:
- Still no 10 second pass, but it was a new setup, so it was to be expected
- Weather was not great; it was warm and humid with a slight headwind
- Had an issue getting into 2nd gear on 2 of my 6 passes, which has never happened before
- Cut the best 60' time I've ever had (1.67 seconds), but it was unfortunately on a pass where I missed 2nd gear

Mods this time with differences highlighted:

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; McLeod RST Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies; Underdrive Pulley
Tires: Hoosier DR2 (335/30-18), set to 24-22 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,650+ lbs - I was a bit heavy starting with 3/4 of a tank of gas that night, the substantially heavier clutch assembly (+22 lbs), and subwoofer still installed (+30 lbs).

I ended up making 6 passes total. The results (right lane for all 6):

https://i.ibb.co/Pjtx35C/Actual-Time-Slips.png

And an Excel screen capture that's a bit easier to read, including the Density Altitude readings from my Kestrel 5100:

https://i.ibb.co/5hTN5jp/Excel-Screen-Cap.png

So the biggest differences this year were the addition of an underdrive pulley and the swap from the Nth Moto carbon triple disk clutch to a McLeod RST, which is their street twin that bolts to the stock flywheel. Anyone that has shopped for clutches knows that the Nth Moto clutch isn't cheap at over $4k, so swapping to something seemingly inferior was not a decision I made lightly. I spent the winter mulling the idea over...in the process of doing that, I went back through this thread and this quote stuck out to me:

Regarding your clutch, nothing aftermarket that is like an on/off switch is going to work great at a prepped launch pad. IMO finding a very durable organic clutch (maybe even stock) that you can slip the crap out of and just look at it as a consumable part that you'll need to replace every 12 runs or so. Also, figure out how to keep your clutch fluid as cool as possible to keep it consistent for good launches.

The Nth Moto clutch can be slipped just fine on the street, but get some heat into it, and it just grabs. Unfortunately, the lower rotating mass combined with my porky Gen 4 caused my car to fall on its face even with some 5,500 RPM dumps out of the hole. I was beyond frustrated. I knew I wanted to try something heavier, which the McLeod certainly is - pretty much identical to the stock clutch at 61 lbs vs. 39 lbs for the Nth Moto. As I said above, it just bolts to the stock flywheel - it has its own flywheel, so you don't have to resurface anything; it just bolts in place and off you go. The install was SO much easier, which was nice for a change. Here's a quick pic:

https://i.ibb.co/frPb3XH/Mc-Leod-RST.jpg

The flywheel looks used because it is - I ended up keeping my original around just in case I ever wanted to do something like this. The clutch drives like a dream on the street - very smooth engagement, and shifts are like butter. You notice the extra mass, but it isn't all bad - it makes for smoother low RPM driving and much easier take offs. Overall, I was pleased with the decision.

At the strip, I think it was a step in the right direction - I cut two of my best 60' times ever (1.67 and 1.74), but getting locked out of 2nd gear a couple of times was definitely cause for some concern. Did I get the clutch too hot, or was I just hammering it into 2nd too hard? After the 2nd time, I almost decided to call it a night, but I'm glad I kept going because I ended up getting a few more clean passes, which gave me confidence that I didn't hurt anything too badly.

Obviously I didn't reach my goal, but it was a good night for shaking everything down and clearing out the cobwebs. My driving was just off all night long, but that's what you get for not doing something for a while.

On a positive note, I ended up upgrading my action cam from a first generation GoPro to a GoPro Hero 9 Black. Man what a difference in the quality of the footage, especially in low light conditions:

https://i.ibb.co/qJ1sKV3/Go-Pro-Comparo.jpg

...and zoomed in a bit:

https://i.ibb.co/LtBfLWc/Go-Pro-Comparo-Zoom.jpg

I also got to exercise the gauge display that was part of last winter's double DIN head unit install: https://driveviper.com/forums/threads/27849-My-Double-DIN-Head-Unit-DIY-Install?p=432427&viewfull=1#post432427

I now have a good way to monitor the IATs (which got to over 100° on a couple of passes even in 78° weather) as well as ECT, RPMs, Timing Advance, and MAP:

https://i.ibb.co/tqjC8FQ/Gauges-Display.jpg

It doesn't help when I'm concentrating on the pass, but my new GoPro has good enough resolution that I can read it well enough on the replay to get a good idea of what's going on.

I also added a Dragy to capture 0-60 and 60-130 times:

https://i.ibb.co/VCPq6jF/Dragy-0-60.png

https://i.ibb.co/y0V48Mj/Dragy-60-130.png

I now have lots and lots of data to go through after every pass. It's a bit overkill, but I still find it interesting. More on that a bit later.

J TNT

10-10-2021, 07:43 AM

Lots of great information and detail Steve , thanks for sharing!
Love your approach.

viperBase1

10-11-2021, 10:36 AM

49425
You're knocking on 10's door! :dude3:

Hey maybe add a little air to them tires!

but getting locked out of 2nd gear a couple of times
Sudden Skip Shift? I'm a dork just grabbing at straws. :witless:

https://i.ibb.co/frPb3XH/Mc-Leod-RST.jpg
Great pic of your new McLeod RST!

Here's mine ..before being mounted.
49424
Didn't get a pic of it installed. :(

Steve M

10-11-2021, 01:32 PM

You're knocking on 10's door! :dude3:

I've been knocking on that door for years. I'll get there, or I'll put my foot through the firewall trying.

Steve M

11-13-2021, 11:30 PM

Event: Thursday Night Test & Tune
Date: September 30, 2021
Location: Kil-Kare Dragway (Dayton, OH)

The highlights:
- The weather was great - it started out warm, but a high pressure system had just moved in, the humidity was noticeably lower, and there was a slight tail wind that night (rare)
- Yet again had an issue getting into 2nd gear on 1 of my 4 passes (starting to see a trend here?)
- My 60' times were disappointing all evening; I thought I had learned a lot about launching with the new clutch during my last outing, but I was oh so very wrong

Mods this time with differences highlighted (no major changes since 9 September 2021):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; McLeod RST Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies; Underdrive Pulley
Tires: Hoosier DR2 (335/30-18), set to 24 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,600+ lbs

I came up with a new way to estimate my race weight based on the last time I had it on the scales (should be within about 20 pounds or so of reality), and I also put some time into making some better graphics that show the weather conditions as well as how much gas I had during my first and last passes of the night:

https://i.ibb.co/7yxjfqJ/Conditions.jpg

I put more time into that than I'd care to admit.

I ended up making 4 passes total. The results (right lane for all 4):

https://i.ibb.co/7JSBh7H/Time-Slips.jpg

The Excel screen capture including the Density Altitude readings from my Kestrel 5100:

https://i.ibb.co/ZGGrHnS/Excel.jpg

Dragy 0-60 times:

https://i.ibb.co/3B83005/Dragy-0-60.jpg

Dragy 60-130 times:

https://i.ibb.co/QjJh1dm/Dragy-60-130.jpg

At this point, I was starting to suspect my issue with missing 2nd gear (and only 2nd gear) was related to trying to powershift first to second gear. By the 4th run, I was granny shifting 1-2, and that seemed to fix that problem (but it won't be the last time you'll see this problem rear its ugly head...).

I was really digging the 60-130 time on my last pass (7.55 seconds!) - that was the result of powershifting 3-4. It makes all the difference with the 60-130 times, and also seemed to help with the trap speed as that was my highest ever at 130.89 MPH, even with the heavier clutch assembly.

Video of that pass (note the much better video quality thanks to a GoPro that was made during this decade):

https://youtu.be/aFX4Q_C3WHc

Aside from the shifting issues on the 2nd pass, I felt like I was starting to get a good feel for the new clutch. Little did I know that the honeymoon would end a short couple of weeks later...

viperBase1

11-14-2021, 08:38 AM

The acceleration trace on the Draggy doesn't make sense to me :witless: The Speed trace is linear but the acceleration trace is variable??

Aside from the shifting issues on the 2nd pass, I felt like I was starting to get a good feel for the new clutch. Little did I know that the honeymoon would end a short couple of weeks later...

What does "the honeymoon would end a short couple of weeks later" mean exactly?
Did the McLeod RST fail in some way?

Steve M

11-14-2021, 10:09 AM

The acceleration trace on the Draggy doesn't make sense to me :witless: The Speed trace is linear but the acceleration trace is variable??

It's an artifact of the scale and the units it is showing. Referencing the 0-60 times above from September 30th, look at run #2. Notice where the blue line (speed) goes flat - I'm still going ~50 MPH, but I'm no longer accelerating because I couldn't find 2nd gear with two hands and a flashlight. The yellow line (acceleration) shows a corresponding dip (down to about 0 g's of acceleration).

The 60-130 plots are similar - the dips in the yellow trace line up with where the blue lines go flat for a fraction of a second. The first dip in the yellow line on those plots represents the 2-3 shift (around 70-ish MPH), and the second dip shows the 3-4 shift (around 100-ish MPH). The fastest shifting cars will have a smooth sloping blue line with tiny blips in the yellow trace. Longer dips (left-to-right) in the yellow line = slow shifting = :(

If they changed the scale, the yellow line would look a bit less noisy, but you'd also lose a little bit of the sight picture it offers. Take a look at this thread in the Gen 5 section - lots of plots and videos to compare against: https://driveviper.com/forums/threads/8162-Gen-5-Vbox-Data-60-130-mph-times/page4

Bottom line: all this stuff is happening so fast that I can't tell the difference between a 7.7x and a 7.5x 60-130 time. I don't get a chance to check after each run until I'm back in the staging lanes getting ready for my next pass, so it's always a bit of a surprise to see how I did. That's also why I take video footage of each of my quarter mile passes - I watch them over and over again to see what I did right and wrong so I can learn. It's amazing how much stuff you miss in the heat of the moment. Start to finish a run takes about a minute, the last 11 seconds of which is pretty frantic.

What does "the honeymoon would end a short couple of weeks later" mean exactly?
Did the McLeod RST fail in some way?

Putting that story together now...

Steve M

02-03-2022, 12:15 PM

Event: Thursday Night Test & Tune
Date: October 14, 2021
Location: Kil-Kare Dragway (Dayton, OH)

The highlights:
- The weather was average - it was warm, and a bit on the humid side
- Everyone was breaking shit - I ended up having to wait 1.5 hours before getting my first pass, and almost another 2 hours before making my second (and final) pass

Mods with differences highlighted (no major changes since 30 September 2021):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; McLeod RST Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies; Underdrive Pulley
Tires: Hoosier DR2 (335/30-18), set to 24 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,600+ lbs

Weather conditions and estimated race weight:

https://i.ibb.co/sW0Z5Wt/14-Oct2021-Weather.jpg

There was apparently a photographer (Chris Minzler) at the track that night...randomly ended up seeing these posted online:

https://i.ibb.co/mCTLJ57/Staging-Lane.jpg

https://i.ibb.co/2c6248d/Viper-Collage.jpg

Those burnout pics were taken right before this happened:

https://youtu.be/Sc7TZpyVrZQ

I was beyond pissed...missing 2nd gear was becoming a bit too common, but hitting 4th instead was the straw that broke the camel's back. I grabbed my time slip and drove straight home. Couldn't even see straight I was so pissed.

Standard complement of time slips and Dragy data below.

https://i.ibb.co/H2nrLvC/14-Oct2021-Time-Slips.jpg

Excel screen capture including the Density Altitude readings from my Kestrel 5100:

https://i.ibb.co/ch87yRw/14-Oct2021-Excel.jpg

Dragy 0-60 times:

https://i.ibb.co/7yQKtdx/14-Oct2021-Dragy-0-60.jpg

Dragy 60-130 times:

https://i.ibb.co/ykdBgwQ/14-Oct2021-Dragy-60-130.jpg

I spent the next day at work sulking, and tossed and turned all night Friday night into Saturday when I suddenly decided that pulling the transmission needed to happen. I knew it was either a clutch problem or a transmission problem - I had a spare clutch laying around (the old Nth Moto triple carbon), but not a spare transmission. The racing season was winding down, and I only had two more Thursday nights left in the racing season before they shut the track down for the year. I figured I had nothing to lose by putting the old clutch back in and seeing what happens, but I only had a few days to get everything sorted.

Story to be continued...

viperBase1

02-06-2022, 08:56 AM

Steve I realize you're racing THE CLOCK more than the car in the other lane, but from the video it looks like you still smoked 'em even on a 1 - 4 shift. :dude3:

N' btw your car is lookin' bad ass in those pics.

Steve M

02-06-2022, 10:39 AM

N' btw your car is lookin' bad ass in those pics.

Thanks...all credit goes to the photog. I just show up with my B-game. But one of these days...one of these days I'll finally live up to this car's potential.

Steve M

02-06-2022, 11:41 AM

Event: Thursday Night Test & Tune
Date: October 21, 2021
Location: Kil-Kare Dragway (Dayton, OH)

The highlights:
- The problem I was having shifting was definitely the clutch - switching back to the Nth Moto Triple Carbon fixed it
- I managed to squeeze in 6 runs...much better than the 2 runs I got the previous week
- The weather was...interesting. A cold front had just moved through, so temps were falling (good), but that came with a nasty 20 MPH cross-wind that turned into a 15 MPH head wind as the night went on (not so good)

Mods with differences highlighted (one major change since 14 October 2021):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; Nth Moto Triple Carbon Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies; Underdrive Pulley
Tires: Hoosier DR2 (335/30-18), set to 24 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,600 lbs

Weather conditions and estimated race weight:

https://i.ibb.co/61MpB3W/21-Oct2021-Weather.jpg

Long story short, I was able to get the McLeod RST swapped out for the old Nth Moto triple carbon within a week to salvage what was left of the 2021 racing season. It was not a decision I made lightly, and it certainly cost me a lot of time, but I had the parts and tools needed on hand, so I made it happen - on my back, in my garage. I was very concerned I had a transmission problem, but after swapping the old clutch back in and bleeding the clutch hydraulics really, really well, the transmission worked great. As a matter of fact, it had never shifted so well. I ended up only having one quick test drive plus the 30-minute drive to the track to reacquaint myself with it, but that's life sometimes.

The first pass of the night was the big one from a pucker factor standpoint. I was the first street car down the track that evening, and it was a solo run (that's a slightly longer, but uninteresting story). I managed a successful 2nd gear burnout and a pretty weak launch, but the 1-2 shift was my biggest concern. Once I successfully made that shift, it was pretty much smooth sailing from then on. As a matter of fact, it was my quickest first pass of the day ever by almost a tenth of a second, which I found really promising.

Unfortunately, that didn't pan out to a 10-second pass, but between the track conditions and the weather, it just wasn't meant to be. Still, the car was consistent across all six passes (minus the second one where I spun off the line), and that gave me a lot of confidence that I'm heading back in the right direction. I clearly picked up some bad habits launching the McLeod RST that just didn't translate well to getting the car off the line with the substantially lighter clutch assembly, and oddly enough, 6 passes spread out over 3.5 hours on a test and tune night just wasn't enough for me to get my technique sorted.

I ended up having a couple of good runs against a stock Durango Hellcat though (runs #3 and #4):

https://youtu.be/gEGMt16AXpk

He got me off the line bad on both runs, but I was able to chase him down and pass him by the eighth mile.

Standard complement of time slips (ignore the time stamps) and Dragy data below.

https://i.ibb.co/fYZSppt/21-Oct2021-Time-Slips-1-3.jpg

https://i.ibb.co/cyzYCWG/21-Oct2021-Time-Slips-4-6.jpg

Excel screen capture including the Density Altitude readings from my Kestrel 5100:

https://i.ibb.co/WGCSS8L/21-Oct2021-Excel.jpg

Dragy 0-60 times (average without 1ft rollout = 3.56 sec; average with 1ft rollout = 3.3 sec):

https://i.ibb.co/dMjD5Vw/21-Oct2021-Dragy-0-60.jpg

Dragy 60-130 times (average = 7.67 sec; best = 7.56 sec on run #4):

https://i.ibb.co/tbMz4M8/21-Oct2021-Dragy-60-130.jpg

2quik6

02-06-2022, 10:27 PM

Steve M

02-06-2022, 10:36 PM

Great info and great determination! Looks like you are winning most all of the races still, cut that reaction time down and those wins will be a little easier. I have drag raced automatics for many decades, mostly an '87 Grand National for the last 25+ years. Trying to just do a good burnout much less launching the Viper is an art of its own! My hats off to you for being able to do that well.

Thanks!

My reaction times are all over the place...I think I've only red lit once in the 50 passes I've put on this car. Generally I'm trying to concentrate on my launch, but I can never seem to be able to ignore the person in the other lane going and me just sitting there like a goober.

And my line lock makes the burnout really, really easy (or in other words, I cheat). I've never been coordinated enough to do it only with my feet, especially when the pedals are so close together in this car.

Steve M

04-03-2022, 09:31 PM

I still have a bunch of lessons learned from last year to add to this write-up, but just haven't had the time to put it all together. I don't think most will find them all that helpful, so I'll leave those on the back burner for now until I get some down time.

So what's next?

I haven't achieved my goal yet, but I'm still not out of ideas.

With the addition of the underdrive pulley last year, I'm all out of power adding mods unless I'm willing to add headers, and at this point, I'm still not willing to do that.

I can however, pull some weight out of the car, and that's what I intend to do (and pretty much already have).

Over the winter, I managed to pull 50 pounds out of it pretty easily (although it wasn't cheap). If I ditch the subwoofer (32 pounds) and a few other odds and ends, I think my race weight will be 80-90 pounds lighter compared to last year's final runs.

I'm also going to try to get out there earlier in the season, hopefully either later this month or early next month before the summer heat hits. It'll be the 3rd season on these drag radials, so we'll see if they get me through the rest of this year.

Aevus

04-03-2022, 11:21 PM

So what's next?

I haven't achieved my goal yet, but I'm still not out of ideas.

Steve, maybe:

- 3.73 gears?
- A new tune?

... a camshaft?

Patentlaw

04-04-2022, 02:01 AM

Hi Steve,

Well, you asked. Up to now, you have tried the following:
1) Stock car
2) Different weather conditions
3) Modifications

At the first post, others have done it, through your videos. The only thing that you have not "modified" is the driver. Not trying to be a jerk. If similar cars can do it, and you have one, the only difference is the driver.

Drag Racing School is your answer. You need to go to school to have someone give you pointers. No more modifications are probably necessary for your car.

Steve M

04-04-2022, 08:47 PM

Steve, maybe:

- 3.73 gears?
- A new tune?

... a camshaft?

3.73 gears would require me to raise the rev limiter with my current wheel/tire combo, but would likely help. Streetability would suffer though.

I've messed with the tune once trying to improve what I already had, and it netted me a 10-15 HP loss, so I vowed to never mess with it again unless I changed something with the engine configuration.

A camshaft is out of the question because of my current desire to maintain the drivability of the stock cam. The car still has excellent road manners...the ride is smooth, and the car drives exactly like stock until you get on it. My overall goal was to not lose any of the civility of the stock configuration, although I had to make a bit of a compromise with the clutch to gain the durability (the downside being the stiffer pedal).

There is one mod you didn't mention, and it is one that I think would solve the problem outright: switching to an automatic transmission. All the fast cars at the track run autos. My pride won't let me do it though. That, and my wallet...that would be one very expensive swap.

Hi Steve,

Well, you asked. Up to now, you have tried the following:
1) Stock car
2) Different weather conditions
3) Modifications

At the first post, others have done it, through your videos. The only thing that you have not "modified" is the driver. Not trying to be a jerk. If similar cars can do it, and you have one, the only difference is the driver.

Drag Racing School is your answer. You need to go to school to have someone give you pointers. No more modifications are probably necessary for your car.

It was intended to be rhetorical, but I wasn't explicit. And, you make a solid point.

I definitely know that I'm the biggest variable that needs changed at the moment. My intent with any of the mods done is to eliminate as much of the driver variable as possible, if that makes sense.

It all comes down to the launch, and the only way to get that one down is more seat time. I have some things in mind I'm going to try, and we'll see what it gets me. I don't think there's a drag racing school out there that would help with my exact problem, mostly because what I'm trying to do is run a set elapsed time with my own car, not learn how to drive a purpose-built drag car which is what seemed to be available out there after a quick online search.

Aevus

04-04-2022, 09:37 PM

3.73 gears would require me to raise the rev limiter with my current wheel/tire combo, but would likely help. Streetability would suffer though.

You're hitting the rev limiter with your 3.55 at the end of the 1/4?
and whats the RPM limit at the moment?

streetability? uhm, going from 3.55 to 3.73 is very mild (+5%). In fact you could even consider 3.91 (+10%)

Aevus

04-04-2022, 09:39 PM

...just to be sure: 10.99 sec and you're finally opening the bottle of Champagne, am I right?

Steve M

04-04-2022, 09:56 PM

You're hitting the rev limiter with your 3.55 at the end of the 1/4?
and whats the RPM limit at the moment?

streetability? uhm, going from 3.55 to 3.73 is very mild (+5%). In fact you could even consider 3.91 (+10%)

I'm going through the traps around 6,000-6,100 RPMs or so with my current gearing (3.55s). After going through my gear ratio calculator spreadsheet, I was mistaken - the 3.73s would probably be about ideal with my current rear tire (335/30-18 Hoosier DR2) as the max speed @ 6,600 RPMs on a ~26" tire would be about 136 MPH.

But my primary concern is still the streetability. With the 3.55s currently in there, the car already won't hook on the street from a 2nd gear roll on anything less than an R-compound tire. 3.73s would only make that worse.

Steve M

04-04-2022, 09:57 PM

...just to be sure: 10.99 sec and you're finally opening the bottle of Champagne, am I right?

I think the car has a 10.6-10.7 in it, but I'd still be happy with a 10.999.

Aevus

04-04-2022, 10:40 PM

But my primary concern is still the streetability. With the 3.55s currently in there, the car already won't hook on the street from a 2nd gear roll on anything less than an R-compound tire. 3.73s would only make that worse.

Oh ok that's surprising, I have roughly 580hp @ crank at the moment and with the Wavetrac diff, 3.73 gears and 355 Kumho ACRs tires it's actually very hard to make it spin on a roll, unless the tires are cold.

I'm actually installing 4.10 gears this week (for my upcoming high-rpm engine)

Aevus

04-04-2022, 10:43 PM

I think the car has a 10.6-10.7 in it

Now you're being greedy

:t0122:

Steve M

04-21-2022, 10:30 PM

https://i.ibb.co/VqSz6xV/10-Second-Slips.jpg

proedge

04-21-2022, 10:41 PM

got into the 10's! congrats

Steve M

04-21-2022, 11:19 PM

Didn't take long for it to show up on YouTube apparently (random guy filming the runs tonight in the stands):

https://youtu.be/6VWCfYKaMF4

Old School

04-22-2022, 06:47 AM

Congratulations!

Aevus

04-22-2022, 11:23 AM

10.86 !

Congrats Steve

J TNT

04-22-2022, 01:20 PM

Congratulations Steve that’s awesome !!!

98intrigue

04-22-2022, 04:13 PM

A long time coming. Congrats, Steve!

viperBase1

04-23-2022, 04:24 PM

Congrats Steve, you finally did it!! :dude3:

So what was the final config?

Patentlaw

04-23-2022, 10:09 PM

Congrats Steve. Your post has been great to watch for some time and is really valuable for those looking to get lower times. Your car is a beast and the driver good as well.

Steve M

04-30-2022, 11:17 PM

Event: Thursday Night Test & Tune
Date: April 21, 2022
Location: Kil-Kare Dragway (Dayton, OH)

The highlights:
- Finally got my first 10 second pass (10.86), and managed to back it up 2 runs later with a 10.94

Mods with differences highlighted (one minor change since 21 October 2021):

Power Mods: Metallic Substrate High Flow Cats; Gen 5 Intake Manifold; HPTuners custom tune (mine)
Supporting Mods: AEM 30-0300 Wideband O2 Sensor; DSE Heat Shield; DSE Closeout Panel; MCS Shocks; TDS Level 5 Axles; Ecliptech Shift Light; Parking Brake Cable Relocation Kit; Nth Moto Triple Carbon Clutch; Moroso Spark Plug Wires; Line Lock; Metal Throttle Bodies; Underdrive Pulley
Tires: Hoosier DR2 (335/30-18), set to 24 psi hot mounted on Forgestar F14s (18x13 rear, 18x11 front)
Rear Gears: 3.55
Race Weight: ~3,524 lbs

Weather conditions and estimated race weight:

https://i.ibb.co/VHdhNRS/Weather.jpg

Bottom line: I pulled some weight out (around 90 pounds worth). Here's what I did to get there:

- StopTech 2-piece slotted rotors (thanks Jon B!) - saved 31.3 pounds
- Pulled the subwoofer - saved 32 pounds
- Interior weight reduction - pulled the center "subwoofer" assembly (saved ~8.5 pounds), and pulled the spare tire inflation device (saved ~4.3 pounds)
- Swapped to the DSE carbon fiber belly pan (reason here: https://driveviper.com/forums/threads/29783-2017-ACR-Trans-and-Diff-Fluids-and-Quantities?p=455860&viewfull=1#post455860) - saved 6.6 pounds
- Ditched some gear - laptop + HPT interface (put it in my wife's car, saved ~7 pounds)

That's 89.7 pounds for those counting. The car is still what I'd consider a full interior car - all seats still installed, it still has a functional stereo (minus the bass), all interior panels in place, all interior carpet in place. The factory center subwoofer has always been a disappointment, so ditching that thing was an easy choice. Should have done that years ago.

And now on to the story.

I had been watching the weather all week. It was supposed to rain that morning, but clear out around 1 PM or so, and then rain later that night. The forecast ended up doing exactly that, leaving a nice window for a standard test & tune night. The humidity was a bit high, but the the temperature was about perfect, the barometric pressure was up, and there was no massive head wind this time. I showed up around 4:30, and was the first one through tech inspection. I immediately went to the staging lanes, and proceeded to go through my normal pre-race stuff (mainly just lowering the rear tire pressures). 5 o'clock rolled around, and it was only me and a couple other cars at that point, which is unusual; normally there are about 20 cars ready to go, increasing to 100+ by the end of the night. This is the earliest I've ever been out during the racing season, so maybe that's normal. I have a feeling the weather forecast had scared a lot of people off though...definitely their loss.

On my first pass, I decided to try doing a much lower RPM launch, slipping the clutch as best I could to keep the car from bogging. That resulted in one of the worst 60' times I've ever had (~2.2 seconds). When I got the time slip, the only thought that went through my head was "this is going to be a long night." I pulled back into the staging lanes, and there wasn't anyone there. The guy directing traffic asked if I wanted to go again, so I said sure, why not? Never had a chance to hot lap the car, so might as well take advantage. I ended up launching the car at around 4,000 RPMs with a slight slip, and the car seemed to take off okay. It felt just like any of my other runs actually...the truck in the left lane took off like a bat out of hell, so I was doing my best to not screw up my shifting so I could get around him after the 1/8th mile. When I pulled around to get my time slip, I was stopped by one of the track workers (which was a bit odd)...once he saw I had my fire jacket and helmet on, he gave me the thumbs up and sent me on my way to the time booth. I grabbed the time slip, and just about shit myself when I saw the time: 10.86. It took a few seconds to register what had just happened, but I was finally holding that coveted time slip in my hand. Clearly that launch worked - it netted a 1.68 60' time. Guess the light weight Nth Moto clutch just requires some practice, and more importantly, patience.

I went back to the staging lanes intending to let the car cool off a bit, but there still wasn't anyone there. Guy asked if I wanted to go again, so I decided to give it another whirl. That one wasn't quite as impressive - an 11.05, which was pretty similar to what I was running the last time I was out on 21 October. After that pass, I parked the car and joined my family in the stands to watch some of the action while everything cooled off.

About an hour later, I decided to give it one more shot...I was really hoping to back up that first 10 second slip with another to prove it wasn't a random fluke. I was actually feeling a lot of pressure from the track announcer - while the track crew was cleaning up a mess in the left lane (which took about another hour, and resulted in them shutting that lane down), the announcer said something to the effect of "And there's a Dodge Viper in the staging lanes!" The guy seemed pretty enamored with it, so I really wanted to put on a good show for him and the rest of the crowd there, and hopefully not embarrass the Viper nation in the process. I ended up having to fiddle around with my line lock during the burnout (hit the button before I had pressure on the brakes), so I was already looking like a total amateur. Rolled up to the line, and then proceeded to launch the car a little soft (~1.80 60' time), but that's apparently all it took. When I grabbed that final slip, the guy at the booth said "Nice run!"...I looked at the time slip, and saw the 10.94 - mission accomplished.

Finally.

I still need to edit the videos I have, but the 10.86 run showed up on YouTube (shown a few posts above) that evening, and someone else caught the 10.94 and managed to find me on Instagram to let me know it was on his channel:

https://youtu.be/4w8O6xGbTMU

The guy filming was there in his Ford Explorer running high 11s that night...definitely impressive.

Standard complement of time slips (ignore the time stamps on the first three runs) and Dragy data below.

https://i.ibb.co/MgZRKT1/Time-Slips.jpg

Excel screen capture including the Density Altitude readings from my Kestrel 5100 (you can see me carrying it in my hand in the staging lanes in the video above):

https://i.ibb.co/G7dxQYr/Excel.jpg

Dragy 0-60 times (average without 1ft rollout = 3.66 sec; average with 1ft rollout = 3.33 sec):

https://i.ibb.co/DgC84NY/Dragy-0-60.jpg

Dragy 60-130 times (average = 7.46 sec; best = 7.37 sec on run #4):

https://i.ibb.co/W28JYW6/Dragy-60-130.jpg

That 7.37 second 60-130 time is a new personal best; it's too bad I didn't do that well on my record quarter mile pass - it would have been deeper in the 10s for sure.

But still - the car performed well, and I was able to drive to and from the track without issue. Even without a 10 second pass, I would have called that a successful evening. My 1/8th mile trap speeds were higher than they've ever been, and the car trapped just over 130 on every single pass in the quarter. As-is, the car is reliable and runs consistently pass after pass, even hot lapping it.

If you'll recall, these were my goals from the first post:

1. Run a solid 10 second pass in a full weight car under average weather conditions (low 70s ambient temps, usually good for +2,000 ft DA around here)
2. Trap 130+ in average weather
3. Limit power mods to basic bolt-ons and tuning, but no headers (I have personal reasons for this, but won't get into it here)
4. Drive the car to and from the track, no trailers - I also don't want to touch a wrench while I'm there. If it requires anything more than a tire pressure gauge, it's a no-go.

Have I achieved those goals? I personally feel like I have. The weather was clearly above average for my 10-second passes, but the car has proven many times that it has what it takes to go 10s even in +2,000 DA weather. It's trapped 130 with a DA as high as +2,372 feet, so I feel like #2 can be checked off. The car still has stock exhaust manifolds (and stock mufflers), so check #3 off. And the only tool I had on me at the track was my tire pressure gauge, so you can check #4 off too.

Others may disagree, but I don't feel like I have anything else to prove at this point. This journey has taken me about 5.5 years from start to finish, and there have been many disappointments along the way. I haven't cracked open the champagne, but that's only because I don't care for it...I'm more of a Dr. Pepper kinda guy. But I can assure you, I'm walking around these days feeling like a massive burden has been lifted off my shoulders...that monkey I've been carrying around on my back was starting to get pretty heavy. I can now go to my grave knowing I was able to drive a stick shift car into the 10s, and there aren't many folks out there that can say the same.