2012 BRZ/FR-S Stock Class Autocross Discussion

[EMguy]

This is probably a little early as the BRZ/FR-S hasn't been classed yet, but it seems a good idea to have a single thread for those competing in stock class autocross.

Here's a quick run down of the hight points of the rules: Link to 2012 rules

-Stock sized wheels (17x7) with +/- 0.25 in (6.35mm) of offset allowance
-Shocks with up to two external adjustments (with stock springs)
-Substituion/removal of either the front or rear sway bar (but not both)
-If offered by the manufacturer, crash bolts are legal (Please Subaru/Scion!)
-Provided it passes sound, exhaust is free after the cat.
-A few other odds and ends

Tires:
The 245/40/17 A6 seems like the natural fit. 225/45/17 and 225/40/17 are other options if the front inboard strut clearance proves too tight.

Any thoughts?

[Sccabrz192]

I'll be competing stock class if/when I no longer have a seat in the solstice. I'm reserving all decisions on modifications until I atleast have the car, take some measurements and take a few runs. I dont like making changes until I have a baseline... The only exception to that is wheels... Which as mentioned in the other thread, not a lot of options at the moment. Though I will say i anticipate the 225/40 being fairly useless, sounds like the car is gearing challenged and a shorter sidewall will make it worse.

[EMguy]

I'm copying over some info from another thread. I'll do my best to keep a running list of some of the stock sized wheels that would work well for autocross.

The stock class rules allow +/- 0.25 in (6.35mm) in offset. So any offset between 42 and 54 is legal. Spacers can be used to acheive maximum offset allowance. Given the relatively tight inboard clearance to the front strut and the fact that you'll want to stuff as much tire as possible in there, I'm thinking that shooting for a 42-43mm offset is probably a good idea.

Lightweight Wheel Options in 17x7, 5x100, ET 42-54:

-Kosei K4R (14 lbs)
-Buddy Club P1 Racing SF (17.4 lbs)
-Team Dynamics Pro Race 1.2 (17.3 lbs)*
-Motegi Traklite 1.0 (14.5 lbs)

*These won't be in stock in the right size, but TD will custom make individual orders to your specs with a 6-8 week lead time. They're reasonable priced, and 17.3 lbs.

[Sccabrz192]

Following bill's lead, you do have some rota options...

GR-A, Boost, and circuit 10 are available in +48
Subzero in a +45

Ill edit this Post if i find others.

[Scooby South]

Originally Posted by Moto-P

I can't disclose what's in plan at HRE yet, but something VERY nice for the FRS/BRZ is coming yes

Ideally though, for race track use, I like to use probably something like 18x8.0 or 8.5, with TRD N1/Taikyu- specified tire size of 225/40ZR18 +45~48 on all four to keep the inherent balance and alignment data.

For street, just about anything goes as I am of the 80's tuner mentality, and I like them low, flush, and functional... The last word 'functional' being the key word though. not mad camber and not hellaflush widebody ride on sidewall craziness...no.. LOL! So perhaps a 18x9? 19x9? slightly pulled tire and agressive offset of about +30 on deep rim 3 piece? I dunno. I'm curious what HRE will pull out of the bag (though they are not casually affordable by any means), as well as new line from Volk, Work, SRR, and Enkei as well for this car rumored. Pro-Drive in white would be nice and racy too though!

There seems to be more options coming.. ummmm HRE...$$$$$$

[Dark_Angle]

So this means that you cannot go to a 17x8 wheel in the stock class?

[Scooby South]

Originally Posted by Dark_Angle

So this means that you cannot go to a 17x8 wheel in the stock class?

true....you never could...you have to run the Stock Size wheel..in this case 17x7... 17x8 would put you into street touring...

Bill

[MTeator]

Originally Posted by Dark_Angle

So this means that you cannot go to a 17x8 wheel in the stock class?

Nope... Have to stay stock dimensions... You can only play with offset a bit.

[Dark_Angle]

So what class would this boot me to? Theoretically

[Dark_Angle]

Sorry I posted too soon. Thanks Scooby South

[Scooby South]

Originally Posted by Dark_Angle

So what class would this boot me to? Theoretically

Whatever Street tire class it gets assigned... assuming right now...STX

Bill

[Sccabrz192]

Originally Posted by Scooby South

There seems to be more options coming.. ummmm HRE...$$$$$$

Based on those comments id be surprised if hres were in a stock legal size.

[AX_FRS]

Would it be a good idea to get an oil catch can? I heard that the boxer engine has an especially hard time with blow-by. Any thoughts on this?

[Scooby South]

Originally Posted by AX_FRS

Would it be a good idea to get an oil catch can? I heard that the boxer engine has an especially hard time with blow-by. Any thoughts on this?

not necessary...unless you plan to boost the motor...I am pretty confident that the Factory Breather system is sufficient for the 12.5:1 compression the engine is producing...

Bill