ACR-E, TA 2.0 with SCCA/NASA

[str5010]

While perusing the SCCA rulebook to see where my 2008 ACR fits into the class structure (Super Street I believe) I noticed the following regarding the new ACR/TA 2.0:


Super Street Class Eligible
Viper/Viper GTS (non-ACR, non-
TA) (2013-14)
Viper SRT (non-ACR, non-TA 2.0)
(2015-16)
Viper (NOC)

I didn't see another location in the rule book that listed the ACR-E/TA 2.0 as eligible. I do believe I saw the TA 1.0 listed elsewhere, but can't recall which section it was in.

Has anyone participated in any solo or time attack events with either SCCA or NASA in these cars? If so what class did you run in and what was your experience? How was the car received by your fellow competitors?

[Arizona Vipers]

With Nasa, you would run in TT1 and would do very well in it, especially if you've hot a modded motor. Most cars in that class are highly prepped Vettes.
You have to have a 5.5 to 1 power to weigh ratio, so if you car is 3400 you could have up to 618rwhp.
My '13 is 3200 lbs and about 560 rwhp, but I've been running in TTU (unlimited) just because i haven't taken the time out to get my car dyno'd and weighed by nasa.
Looking at the lap times of the TT1 guys in my area, I am 2-3 seconds faster than them so will be running TT1 soon as soon as I get my car dyno'd. Check out Nasa's contingency stuff here- https://www.nasaproracing.com/contingencies
If you could keep coming in 1st or 2nd you would never have to buy Hoosier's again! That's what I'm after!

[str5010]

Yeah my ACR falls into TT1 as well. It's easier with the NASA formula to figure out so maybe I should have just asked my original question about SCCA and where the new ACR and TA cars fall into their class structure.

Sounds like you're having a good time running with them so far!

[Arizona Vipers]

Yeah my ACR falls into TT1 as well. It's easier with the NASA formula to figure out so maybe I should have just asked my original question about SCCA and where the new ACR and TA cars fall into their class structure.

Sounds like you're having a good time running with them so far!

Does the SCCA take "points" for Aero and stuff like that?

[Bill Pemberton]

NASA is definitely T1 , but you will need to get a fresh Dyno to get it classed , otherwise they will throw you into TTU. The mods put the car into SSM if autocrossing, and it is interesting if running Time Trials in SCCA as they usually go by Autocross classification in many Regions.

[str5010]

NASA is definitely T1 , but you will need to get a fresh Dyno to get it classed , otherwise they will throw you into TTU. The mods put the car into SSM if autocrossing, and it is interesting if running Time Trials in SCCA as they usually go by Autocross classification in many Regions.

Bill,

Thanks, I understand where your ACR fits in now but do you have any customers that have tried to run their stock 2016 ACR with SCCA to see where they fall?

I'm just curious what the response has been. While searching I found some old SCCA discussions from the late 90s when the original ACR was introduced and people were clamoring for restrictions to be imposed.

[Bill Pemberton]

Are you talking Time Trials or Autocrosses ( PS , not my ACR anymore , yours , my friend). Glad to see you will use her as she was built for!

[str5010]

Are you talking Time Trials or Autocrosses ( PS , not my ACR anymore , yours , my friend). Glad to see you will use her as she was built for!

Either one really. When I've run with SCCA before in time trials we used the auto-x class designations as you mentioned. As far as I read in the rule book it specifically excluded the gen V ACR and TA models in Superstreet without providing reference to another class they ARE legal.

It just seemed strange that the SCCA certified all these track records but didn't make it obvious as to how somebody could actually participate with the car at an event.

One step further, what if somebody wanted to run one in SCCA class racing to replace their aging ACR-X?

[Bill Pemberton]

Since you have a Gen IV wondering why you are asking about the Gen V? They likely have the classification in their ongoing regs. that come out by email now. Unfortunately I do not keep them , but you can likely access at www.scc.org or call their Toll Free number in Topeka, Kansas.

Keep in mind folks ( like Cindi Lux ) are running ACR-Xs in Trans Am right now. Usually full blown race cars go right to production classes for autocrosses. ACR-X is likely in TTU or maybe even in TT1 in NASA for Time Trials.

[str5010]

Since you have a Gen IV wondering why you are asking about the Gen V? They likely have the classification in their ongoing regs. that come out by email now. Unfortunately I do not keep them , but you can likely access at www.scc.org or call their Toll Free number in Topeka, Kansas.

Keep in mind folks ( like Cindi Lux ) are running ACR-Xs in Trans Am right now. Usually full blown race cars go right to production classes for autocrosses. ACR-X is likely in TTU or maybe even in TT1 in NASA for Time Trials.

I'm just asking as a curious race/Viper fan. I enjoy the discussion on here as a way to pass the time until the next event I can attend or participate in. Also just wanted to see if anyone had turned a wheel in anger yet in actual competition as opposed to open track days.

Just for fun, that's it.

I've been following those participating in Trans Am the last couple years. Hope to catch them at NJMP this year.

[Bill Pemberton]

NASA should be easy , since with their new rules it is basically a horsepower to weight ratio, unless listed otherwise for extra points. Could fit right into TT1 , but would bet they would see the times around the US and it may be classed into TTU immediately.

Interesting to wonder, but often the groups are a bit slower to classify new models of various automobiles until there is a lot of hard data.

[str5010]

Well I guess the SCCA has seen enough to at least not put them in SS haha.

[jpgunn123]

Well I guess the SCCA has seen enough to at least not put them in SS haha.

At this point, the Gen V ACR is in SSP for SCCA AutoCross classing. Seems like if you want to Time Trial, NASA is the way to go, as SCCA is not particularly active on the time trial front.

The SCCA autocross scene seems to be alive, but more focused on Corvettes and one or two models of Porsches in SS and AS. If you want to race Mazdas, Hondas, Nissans, and Toyotas, the SCCA has many classes to choose from for AutoX. This is why CAM, Good Guys, Optima Ultimate Street Car Challenge, etc. have all become popular in the last 7 years.

[str5010]

Good post, thanks for the info!

[Dfunk]

What would my heads and cam ACR-E be classed in? The tech guy at the previous event was clueless. They hadn't seen one yet. I entered as a guest for fun and didn't care, but now I plan on joining this Sunday and want to make sure they class my car right.

Derek

[Arizona Vipers]

SCCA or NASA?

[Dfunk]

SCCA or NASA?
SCCA. I was listed as Super Street Prepared (SSP) but after reading the rules for that class I should be in Super Street Modified (SSM). The bigger after market cam violates rules set for SSP.

[str5010]

I assume this was an auto-x event, how did it go?

[Dfunk]

I assume this was an auto-x event, how did it go?

Yes it was. Not great. I'm still learning how to drive the car. I used to auto-x a WRX STi and the ACR is completely different animal. I'm running it again this Sunday.

[str5010]

Yes it was. Not great. I'm still learning how to drive the car. I used to auto-x a WRX STi and the ACR is completely different animal. I'm running it again this Sunday.

Haha my previous track vehicle was an STI as well, 2006. Good luck next time out.

[Bill Pemberton]

Been on vacation , but would imagine it would go to SSM , as that was what I ran in my ACR and it had been modified.

[Dfunk]

Been on vacation , but would imagine it would go to SSM , as that was what I ran in my ACR and it had been modified.

Thank you Bill. I registered as SSM yesterday. The officials agreed it was the correct class. I have a track night next Tuesday. I'll finally be able to open it up.

[Bill Pemberton]

Enjoy and I am sure you will have a blast!!

[jpgunn123]

I have run my ACR now at a few autoX (SCCA and PCA). Some push, and the front tires are done. Switching to Hoosiers, as I think they will get more runs, etc. on the A7s than the Kumhos in the front. Will see how they work when I get my new wheels from Finspeed. 18X12s with 335/30/18s and 18X13s with 345/35/18.

Also -- try more rebound in the front for AutoX. Factory setting in the front (7 Bump and 5 Rebound) is the opposite of what you want for AutoX with lots of transitions, slaloms, etc. More like 5 for compression and 7 for rebound.

[jpgunn123]

I got the wheels from Finspeed in ~3 weeks with ground shipping.

Wheels specs: 18X12 and 18X13
Tire Specs: 335/30/18 and 345/35/18 Hoosier A7s

Front weights 50.1 lbs (new tire) vs. 52.2 lbs (new tire) —> 4.2lbs saved
Rear weights 52.8 lbs (new tire) vs. 65 lbs (half worn stock) —> 24.4 lbs saved
Total weight savings of 28.6 lbs rotating/unsuspended mass

Front tread width increase of 1 5/8" per side --> total of 3 1/4" tread width increase
Rear tread width increase of 1/4" per side --> total of 1/2" tread width increase
Total width of 3.75” gain

So — lost 28.6 lbs of rotating/unsprung weight and picked up a bunch of grip. Went out and test drove on roads last night, and feels great. Since the additional width was primarily added inboard in the front, the tracking is still excellent. No rubbing anywhere while driving., but I have not pushed it hard, and the ride height is now 5/16” higher in the front and .4” lower in rear (4 5/16” Front and 5.1” rear). I will likely bring the front down, but it is nice to be able to go back to the stock wheels without having the front be too low.

In checking Front wheel fitment — The front wheels clear at full lock everywhere, except at full droop, where the tire can brush the lowest point of the fender where my gravel protector is (pic attached), and the A-Arm brake duct needs to notched about 1/2" (pic attached). I spent a lot of time measuring the front to come up with the specs for the 18X12.

In checking Rear wheel fitment — Everything clears fine, but the inside wheel weights need to be positioned halfway across the inner barrel to avoid hitting e-brake cable, or you can Loosen the bolt and pivot it a bit (there is a range available where the set tab is in the upright hole) which gives plenty of clearance.

Car has -2.9 camber front with 1/8" total toe out. Rear is -1.7 with 3/8" total toe in.

Shock settings:
For AutoX I have been running 7 or 8 on rebound on the front and taking out a click or 2 of compression. This (added rebound damping) really helped turn in, and slaloms. Will try factory compression (7 bump with 7 rebound next time out). On the rear I have been running the factory recommended, but will likely try upping rebound there too.

I have attached some pictures showing the closest rub point in fender at full lock/droop (very unlikely to ever actually occur while driving), how the top of the tire is still tucked in plenty, and a pic of where the wheel grazes the extra brake ducts.
18995
18996
18997
18998
18999
19002
19003
19000
19001

[allans]

Thanks for the info, very helpful. Best, Allan

[jpgunn123]

Here are a few more pictures of the wheels:


190281902919030