New Clutch option from SPEC

[mblgjr]

As much as I enjoyed the stock clutch, its never been my favorite in terms of overall feel. Once it broke in it felt soft and only grabbed in the upper 1/3 of the pedal travel, yet didnt fully release until full pedal throw was achieved.

Yes the pedal is light, it holds fine, but it weighs quite a bit and isn't drag launch friendly.

After a few conversations, SPEC Clutch has now prototyped a 1000lb-ft + capable twin disc package.

These should be available shortly after SEMA.

CNC billet flywheel & pressure plate; service rebuildable; other friction materials available for higher torque applications.

This setup should be the baseline kit for all around use. 9 pounds lighter than stock, it really helps overall throttle response.

Pedal pressure is slightly stiffer by a fractional amount. Reminds me of what the stock clutch felt like when it was brand new before going softish

Uses a dual material stagger on the discs; makes for smooth engagement, yet clean release.

Im really pleased with how it turned out, Ive put about 100mi on it for breakin.

Uses the stock TOB/slave cylinder.

Love it & glad theres another quality option for the Gen5 aftermarket.

13517






SPEC “SS”Trim (SST) Supertwin for Gen5 Viper. (Part number TBA)



· 1010 ft.lbs static torque capacity. (other levels available to 1500+ ftlbs)

· Dedicated Twin Disk for the application. (not a carryover from earlier versions)

· 9 pounds lighter than factory clutch and flywheel assembly.

· Bolt-in installation for use with factory hydraulics. (no need to modify existing system)

· Unsurpassed holding power while retaining manageable drivability.

· All components assembled and balanced in our own facility.

· All Billet components CNC’d in our own facility.





Pressure plate:

· Billet aluminum pressure plate hat with aircraft grade hardware.

· Billet steel top plate.

· Billet steel floater plate.

· Quick release diaphragm.



Flywheel:

· Billet 6061 aluminum.

· Parallel-ground steel friction surface BOLTED in, not riveted. (customer serviceable)

· Heat treated starter ring gear.



Disks:

· “Hybrid” steel-backed friction surfaces using graphite semi-metallic and kevlar.

· Heat treated carrier plates and springs.

· Gun-drilled hubs broached in-house.

[DZnutz]

price?

[ironpeddler]

I had a spec p-trim clutch/aluminum flywheel in my gt500. SPEC is a quality product but it was to much of an on/off clutch for me. I want a little play in there for the daily driving part, like the stock clutches have. Do you expect this clutch to be the same as the p-trim when it comes to drivability??

[mblgjr]

This clutch is NOT on-off. I consider it progressive, but it does engage/cross over harder than stock.

It is what Id consider 1-step more aggressive than stock

Its 2 new friction materials; I believe Kevlar based. Its not the same materials they've been using in the past.


Sorry I cant comment directly as to pricing; I was the prototype guinea pig. Id expect it to be pretty similar to the GT500 kits.

I hate on/off chattery-grabby clutches in street use.....this does none of that.

[1.8t]

Any issues with flat foot shifting?

[mblgjr]

Havent been WOT with it; have maybe 100mi on it so wasnt hammering it yet.

I took it up to about 5k part throttme; I really do feel that it cuts cleaner than the stock at higher RPM.

Added some more info in orig post. Explains things a bit better.

[FrgMstr]

Got a Spec Super Twin in my Gen IV from JonB. Been in a year now. Holds the power just fine. Rated at 900lbs IIRC.

http://kylebennett.com/files/hfpics/True%20Street%20Tune%20Dyno_Texas%20Mile%20102015. png

20lbs lighter than stock.

https://vorshlag.smugmug.com/Customer-Cars/Kyle-Bs-Dodge-Viper/i-cvBCgjF/1/X3/_DSC4206-X3.jpg

[Tiago]

Ive used the super twin in several TT builds in vettes and fbodies in the past, they have always treated me well.

[Jack B]

Your first paragraph is right on.




As much as I enjoyed the stock clutch, its never been my favorite in terms of overall feel. Once it broke in it felt soft and only grabbed in the upper 1/3 of the pedal travel, yet didnt fully release until full pedal throw was achieved.

Yes the pedal is light, it holds fine, but it weighs quite a bit and isn't drag launch friendly.

After a few conversations, SPEC Clutch has now prototyped a 1000lb-ft + capable twin disc package.

These should be available shortly after SEMA.

CNC billet flywheel & pressure plate; service rebuildable; other friction materials available for higher torque applications.

This setup should be the baseline kit for all around use. 9 pounds lighter than stock, it really helps overall throttle response.

Pedal pressure is slightly stiffer by a fractional amount. Reminds me of what the stock clutch felt like when it was brand new before going softish

Uses a dual material stagger on the discs; makes for smooth engagement, yet clean release.

Im really pleased with how it turned out, Ive put about 100mi on it for breakin.

Uses the stock TOB/slave cylinder.

Love it & glad theres another quality option for the Gen5 aftermarket.

13517






SPEC “SS”Trim (SST) Supertwin for Gen5 Viper. (Part number TBA)



· 1010 ft.lbs static torque capacity. (other levels available to 1500+ ftlbs)

· Dedicated Twin Disk for the application. (not a carryover from earlier versions)

· 9 pounds lighter than factory clutch and flywheel assembly.

· Bolt-in installation for use with factory hydraulics. (no need to modify existing system)

· Unsurpassed holding power while retaining manageable drivability.

· All components assembled and balanced in our own facility.

· All Billet components CNC’d in our own facility.





Pressure plate:

· Billet aluminum pressure plate hat with aircraft grade hardware.

· Billet steel top plate.

· Billet steel floater plate.

· Quick release diaphragm.



Flywheel:

· Billet 6061 aluminum.

· Parallel-ground steel friction surface BOLTED in, not riveted. (customer serviceable)

· Heat treated starter ring gear.



Disks:

· “Hybrid” steel-backed friction surfaces using graphite semi-metallic and kevlar.

· Heat treated carrier plates and springs.

· Gun-drilled hubs broached in-house.

[Jack B]

Some thoughts:

1. Lighter is better for a road course, not the dragstrip. The alum flywheel kills the launch.

2. Lighter clutch/flywheels are prone to set a misfire code due to the new G5 misfire detection scheme, check with Arrow before the purchase.

[viper04]

Some thoughts:

1. Lighter is better for a road course, not the dragstrip. The alum flywheel kills the launch.

2. Lighter clutch/flywheels are prone to set a misfire code due to the new G5 misfire detection scheme, check with Arrow before the purchase.

Interesting point. With the HP tuner you can turn of the misfire detection scheme.

[mblgjr]

m running the Arrow PCM.

No misfire issue thus far. Will update if something changes.

Granted, Im sure if you went ultra-light maybe youd find the threshold

[mblgjr]

And Jack; I agree Im normally on board with heavier flywheels.

I've seen back to back tests of light Vs heavy flywheel setups on Mustangs before, though heavier is easier to launch lighter typically wins out ultimately. At least in a light vehicle.

Also in this case the clutch itself allows for and will tolerate a more aggressive launch (slip off the line).

For me the Viper isnt a drag car so Im looking for proper street manners and occasional HPDE/track days.

[FrgMstr]

I had no issues with Arrow PCM and misfire codes on the Gen IV. Turned those off when I run the HPT Tuner.

As for the alum/chromoly flywheel I went with it for track days and roll racing, and I love it for that. No doubt the car is easier to get off the line from a dig with the stock flywheel. That said the Spec Super Twin does not seem to mind the abuse of using it that way.

[Jack B]

A lot of G2 cars reverted back to steel. An alum flywheeldoes not have good street manners.

The alum flywheel hurts the launch, ask anyone who came from a G1 or G2. We have them and cannot do much abou it. However, it is great for a track car.



And Jack; I agree Im normally on board with heavier flywheels.

I've seen back to back tests of light Vs heavy flywheel setups on Mustangs before, though heavier is easier to launch lighter typically wins out ultimately. At least in a light vehicle.

Also in this case the clutch itself allows for and will tolerate a more aggressive launch (slip off the line).

For me the Viper isnt a drag car so Im looking for proper street manners and occasional HPDE/track days.

[mblgjr]

This particular flywheel is about 3 pounds heavier than stock Gen5.

But the clutch is lighter, thus the total assembly is 9 pounds lighter than oem Gen5.

Its a noticeable change but not drastic by any stretch & still has great street manners. I find it better in certain cases since it blips a little quicker from low RPM.

I forget the total assembly weight but stock was at or just over 40 pounds. Ill weigh it later.

[Jack B]

Oem clutch is 36.5 lbs. The McLeod Clutch is 40.5

I have a G2 flywheel, I will weigh it and post, it is a monster. The flywheel weight is the one that affects the moment of inertia the most.




This particular flywheel is about 3 pounds heavier than stock Gen5.

But the clutch is lighter, thus the total assembly is 9 pounds lighter than oem Gen5.

Its a noticeable change but not drastic by any stretch & still has great street manners. I find it better in certain cases since it blips a little quicker from low RPM.

I forget the total assembly weight but stock was at or just over 40 pounds. Ill weigh it later.

[Tiago]

lol, the tilton clutch setup weighs less than 10 lbs... 40 lbs is retarded, supras with no torque and tilton clutches drag race just fine. The weight of the clutch is not the reason you can or can't launch a car.

[FrgMstr]

lol, the tilton clutch setup weighs less than 10 lbs... 40 lbs is retarded, supras with no torque and tilton clutches drag race just fine. The weight of the clutch is not the reason you can or can't launch a car.

Yup. Not a case of engineering, but rather the user. Practice makes perfect. But it requires practice.

[Nine Ball]

Heavier clutch makes it easier to avoid bog. It does matter, I've tested all sorts of clutches in my manual drag cars and the lighter ones were more difficult to launch consistently. Possible to launch well? Sure. Just inconsistent and took more rpm to do so.

[coupe]

Just for perspective: A flywheel is an "energy storage device." Heavier flywheels transfer more energy to the driveline when you engage the clutch, essentially helping the engine get the car rolling. A lighter flywheel doesn't help the car as much with rolling away from a start, but it does provide less resistance throughout the RPM range when the engine is delivering power. Too light or too heavy either way is only a hindrance IMO.

[mblgjr]

All I can say is having a little weight off seems to be a good all around sweet spot for my taste. :)

[Jack B]

That is not a twin disk, just a guess. Another guess, you have not launched a G5 on slicks.


lol, the tilton clutch setup weighs less than 10 lbs... 40 lbs is retarded, supras with no torque and tilton clutches drag race just fine. The weight of the clutch is not the reason you can or can't launch a car.

[Tiago]

Heavier clutch makes it easier to avoid bog. It does matter, I've tested all sorts of clutches in my manual drag cars and the lighter ones were more difficult to launch consistently. Possible to launch well? Sure. Just inconsistent and took more rpm to do so.

of course it helps, but it is not the end all be all that Jack is making it out to be. It can be managed and in general terms lighter is always better if you can drive it. Plus it is easier on the trans internals :D


That is not a twin disk, just a guess. Another guess, you have not launched a G5 on slicks.

its a triple or a quad.

I launch my car just as well as you if not better, on radials. On slicks it would be much easier. Gen 5 should be easier than my gen 3, since you have shorter gears.

[Jack B]

1.It is impossible for a viper twin disk and press plate to weigh under ten lbs - you are mistaken.

2. Don'T make judgement until you drive one the G3 is far easier to launch - again you are mistaken.

3. Why is a lighter clutch easier on a trans?

4 Why do you think there are only three of us in the tens?

I want to see the video of you launching a G5 - you will get humility pretty quick. Iwill let Nineball speak for himself, he is about as good as it gets, but, I believe it took over 20 runs and a smoked clutch to get a 10.

5.Shorter gear, you are wrong again, the 2.26 first and 3.55 diff is longer than you G3 and that is not even considering ataller tire.

IF YOU CAN SUBSTANTIATE. ANY OF YOUR CLAIMS, I WILL APOLOGIZE AND EAT CROW, HOWEVER, I
EXPECT THE SAME FROM YOU, MAYBE WE ARE BOTH HALF RIGHT


of course it helps, but it is not the end all be all that Jack is making it out to be. It can be managed and in general terms lighter is always better if you can drive it. Plus it is easier on the trans internals :D



its a triple or a quad.

I launch my car just as well as you if not better, on radials. On slicks it would be much easier. Gen 5 should be easier than my gen 3, since you have shorter gears.

[Tiago]

1.It is impossible for a viper twin disk and press plate to weigh under ten lbs - you are mistaken.

2. Don'T make judgement until you drive one the G3 is far easier to launch - again you are mistaken.

3. Why is a lighter clutch easier on a trans?

4 Why do you think there are only three of us in the tens?

I want to see the video of you launching a G5 - you will get humility pretty quick. Iwill let Nineball speak for himself, he is about as good as it gets, but, I believe it took over 20 runs and a smoked clutch to get a 10.

5.Shorter gear, you are wrong again, the 2.26 first and 3.55 diff is longer than you G3 and that is not even considering ataller tire.


I said the tilton setup weighs less than 10 lbs, I never said any of the clutches discussed herein are 10 lbs.

But there are vipers that run the tilton setup and can launch just fine too.

there are only 3 of you in the 10s because very few actually drag race, and even fewer actually can drive LOL!

I know Tony is a good driver, I've seen him at work many times.


It is not easy, but it is doable, a clutch being heavy or light is not the fault is all I am saying.

[Jack B]

The Tilton viper twin disk is NOT less than 10 llbs. What about my other points.

There have dozens that have gone to the dragstrip and this is only from the forums.



I said the tilton setup weighs less than 10 lbs, I never said any of the clutches discussed herein are 10 lbs.

But there are vipers that run the tilton setup and can launch just fine too.

there are only 3 of you in the 10s because very few actually drag race, and even fewer actually can drive LOL!

I know Tony is a good driver, I've seen him at work many times.


It is not easy, but it is doable, a clutch being heavy or light is not the fault is all I am saying.

[Jack B]

For information purposes, I just weighed the G2 flywheel, it is 32 lbs. I think the clutch was 28 lbs.

[Tiago]

The Tilton viper twin disk is NOT less than 10 llbs. What about my other points.

There have dozens that have gone to the dragstrip and this is only from the forums.

No?

http://viperspecialtyperformance.com/catalog/images/Tilton%20CC.JPG

I bet it is very close... that fly wheel is very very light... and I know for a fact that the PP+ discs are around 6lbs all together.


FWIW I have the mcleaud setup in my viper too. I love it.

this is a waste of time, I won't waste mine anymore :)

[mblgjr]

Yall through kicking sand at ea other?

[Jack B]

It is sort of obvious that it bothers me when someone injects bs into a good post. Every point he made was wrong and he couldn't correct any of his statements. As far as the Tilton, I think the viper version is 48 lbs total, they offer a 12 lb, track only clutch that is $6,400. I do not think we have many, if any vipers running a $6K clutch on the street.


Yall through kicking sand at ea other?

[mblgjr]

Fwiw I discussed a smaller diameter/ultra light carbon disc setup. Theyve used them in some of the high HP euro cars with good success. So Im sure it could be done for Viper as well.

When mine was done, I brought up using a steel flywheel but it would be considerably heavier.

[Jack B]

Look on viper specialties website, he has both the 48 lb and the 12lb, $6,400 version, along with a bunch of other aftermarket clutches. If Dan is around maybe he can give us his insight.


Fwiw I discussed a smaller diameter/ultra light carbon disc setup. Theyve used them in some of the high HP euro cars with good success. So Im sure it could be done for Viper as well.

When mine was done, I brought up using a steel flywheel but it would be considerably heavier.

[Nine Ball]

Here is the problem with the Gen 5. You cannot compare good examples of Gen 1-4 launches, and think the Gen 5 is similar. It isn't. The 1st gear ratio in the Gen 5 absolutely sucks. The fact that you can reach 61 mph in 1st gear tells you how long that gear is, it doesn't help you off the line at all. Previous gens had a more aggressive 1st gear ratio, which means you have higher rpm at takeoff, with less wheel speed. That works great when you have limited traction.

The Gen 5 clutch is garbage at the drag strip. Even on softer 1.7 60' launches, it will smoke that clutch good. On a well-prepped track, on sticky tires, the tires have more traction than the clutch does! With the shitty 1st gear ratio, you'll need 5000+ rpm launches to prevent bogging off the line. That means the clutch goes up in smoke, and your sticky tires don't spin at all.

See the problem here? :)

[mblgjr]

Yes...a stock Gen5 isnt meant to be a world class drag racer off the lot. Unless you like taking the return road cutoff at 80mph....

[Fatboy 18]

That Spec clutch looks Great, Shame you have to hide a piece of art like that inside a bell housing :) Nice office paperweight though :D

[Viper Specialty]

Look on viper specialties website, he has both the 48 lb and the 12lb, $6,400 version, along with a bunch of other aftermarket clutches. If Dan is around maybe he can give us his insight.


So... what is the actual question here? LOL

Yes, there is a Tilton "Race" flywheel that weighs about 12lbs, and then we have a "Heavyweight" street version that comes in at about 40lbs. The race flywheel is too light for street use; it is VERY easy to stall, and clutch life is murdered as a result. The Heavy version is much easier to drive, and was designed for Drag/Street. Tilton's have lighting fast up/down shifting with regard to actual transmission gear changes because the MMOI of the floater plates are so low, and synchros have to do so little work. However, the flywheel weight plays into how fast the engine itself can change revs of course. Our goal with the Heavy version was to make a flywheel with nearly the same inertia moment as the OE setup, but weights less overall, which is why it has more weight slung to the outer diameter than center.

[Viper Specialty]

Here is the problem with the Gen 5. You cannot compare good examples of Gen 1-4 launches, and think the Gen 5 is similar. It isn't. The 1st gear ratio in the Gen 5 absolutely sucks. The fact that you can reach 61 mph in 1st gear tells you how long that gear is, it doesn't help you off the line at all. Previous gens had a more aggressive 1st gear ratio, which means you have higher rpm at takeoff, with less wheel speed. That works great when you have limited traction.

The Gen 5 clutch is garbage at the drag strip. Even on softer 1.7 60' launches, it will smoke that clutch good. On a well-prepped track, on sticky tires, the tires have more traction than the clutch does! With the shitty 1st gear ratio, you'll need 5000+ rpm launches to prevent bogging off the line. That means the clutch goes up in smoke, and your sticky tires don't spin at all.

See the problem here? :)


Negatory. You are forgetting that the only thing that matters is Total Torque Multiplication, and Total Drive Ratio in a given gear. Just because the G5 has a different 1st gear does not mean a thing. It also has a 3.55 vs. 3.07, which means the total driveline ratio for first gear is nearly identical to previous generation. Hell, all earlier Gen-3/4 cars were right around 60MPH in first as well.

2.26x3.55= 8.023
2.66x3.07= 8.166
difference = 1.7%

[Jack B]

Dan

1. The G5 does not launch like any past gen.

A. Aluminum flywheel.

B. The tq curve much higher in the rpm band

C. The pcm - right after the clutch is released, the pcm pulls throttle, even though the pedal is asking for additional throttle. During this period the logs show a dramatic negative slope on the rpm and in most cases a bog.

I have driven/drag raced approx 20 high power cars, none have been close to being as difficult as the G5 to launch. I think with my G2 I had a string of ten runs in row that were between 1.68 and 1.7, that won't happen with a G5.

If you want a lesson in humility, please take a G5 to the track. Nineball is correct, the DRs have more grip than a G5 oem clutch.




Negatory. You are forgetting that the only thing that matters is Total Torque Multiplication, and Total Drive Ratio in a given gear. Just because the G5 has a different 1st gear does not mean a thing. It also has a 3.55 vs. 3.07, which means the total driveline ratio for first gear is nearly identical to previous generation. Hell, all earlier Gen-3/4 cars were right around 60MPH in first as well.

2.26x3.55= 8.023
2.66x3.07= 8.166
difference = 1.7%

[Viper Specialty]

Dan

1. The G5 does not launch like any past gen.

A. Aluminum flywheel.

B. The tq curve much higher in the rpm band

C. The pcm - right after the clutch is released, the pcm pulls throttle, even though the pedal is asking for additional throttle. During this period the logs show a dramatic negative slope on the rpm and in most cases a bog.

I have driven/drag raced approx 20 high power cars, none have been close to being as difficult as the G5 to launch. I think with my G2 I had a string of ten runs in row that were between 1.68 and 1.7, that won't happen with a G5.

If you want a lesson in humility, please take a G5 to the track. Nineball is correct, the DRs have more grip than a G5 oem clutch.


Jack,

You completely missed my point. NineBall was stating that the issue had to do with the 1st gear ratio. My only point was that it has NOTHING to do with the 1st gear ratio. I never mentioned any other topic, nor the OEM clutch or launch characteristics.

[Jack B]

I have the G4 trans in mine and it is still hard to launch. I have close to 25 logs of how the throttle reacts to a launch, it sure does not follow the pedal. I am beginning to think that is the biggest factor. On the other hand, in the heyday of G2 racing most of the drag racers that installed aluminum fly wheels, went back to steel.

Sort of interesting, I have a software package that uses a details description of the car/engine to generate the ET. Optimum ET comes somewhere between 1.5 to 2.0% wheel or clutch slip in first gear during the launch. If I have some time I will find the slip for the best ET. As you dial out the slip, the ET suffers. McLeod has a steel disk (strip only) clutch that act like a quasi torque converter, in affect, built in slip.



Jack,

You completely missed my point. NineBall was stating that the issue had to do with the 1st gear ratio. My only point was that it has NOTHING to do with the 1st gear ratio. I never mentioned any other topic, nor the OEM clutch or launch characteristics.

[mblgjr]

Just an update....I still love my spec Gen5 specific setup & its only gotten smoother with a little time. Grabs hard & cuts clean.

[Jack B]

Have you done any dragstrip passes with slicks, is it easy to slip? It is sort of interesting, we had no options for two years and now we have mutilpe choices.


Just an update....I still love my spec Gen5 specific setup & its only gotten smoother with a little time. Grabs hard & cuts clean.

[Revolution]

Whats the price on the spec unit?

[mblgjr]

Have you done any dragstrip passes with slicks, is it easy to slip? It is sort of interesting, we had no options for two years and now we have mutilpe choices.

No slicks...sorry not a diehard quarter mile guy. But I have made 3 launches on stock Corsas and find the setup easier to launch while maintaining the magical amount of tire spin for the Corsas to be happy. You can slip it out and it doesnt go greasy like stocker.


As to pricing I want to say the whole thing waa under 2k

[Revolution]

Who did you get it through spec doesn't list it on their website?

[mblgjr]

Who did you get it through spec doesn't list it on their website?

SPEC “SS”Trim (SST) Supertwin for Gen5 Viper

Call Spec Directly; ask for Matt R. Or Danny and they'll set you up.

Or Matt222@specclutch.com

[FLATOUT]

Appreciate the update!!!