2012 BRZ/FR-S Stock Class Autocross Discussion

[dwx]

I guess the stock wheels are +48 not 42. The section width of a 225/45/17 star spec is 8.9" on a 7.5" rim. A 245/40/17 A6 is 10" but measured on a 9" rim... My guess is on a +50 rim it isn't going to fit without a spacer, with more camber.

I tried running larger diameter tires on my old SM WRX to get some more out of 2nd gear and I hated it and it didn't keep me from having to shift into 3rd most of the time. I used to autox in milwaukee which has a large lot with fast courses. Now I'm in Atlanta where things are tighter and slower.

[Scooby South]

NEWS: I have it on Good Authority... that the BRZ/FRS is 'OFFICIALLY' C-stock..as of about 3 weeks ago... the new Fastrack will indicate that... We all kinda knew that anyways...didn't we???

Bill

[Sccabrz192]

Sounds like I will be ordering my class magnets tomorrow for next weekend

Bill, if you are in the mood for a trek the GLSS divisional event #2 is in MI next weekend, 2 days at a long, fast, albeit a little broken up, asphalt lot. It's going to be a good time!

[MTeator]

Good news.

My first attempt at an alignment for the car blew. I made it too lively. I underestimated the front grip I was able to get with the additional front camber. Any mid corner throttle just brought it around.

Gonna throw it back up on the rack today and adjust it again. I think it's going to be an amazing CS car with some development.

[Scooby South]

Originally Posted by MTeator

Good news.

My first attempt at an alignment for the car blew. I made it too lively. I underestimated the front grip I was able to get with the additional front camber. Any mid corner throttle just brought it around.

Gonna throw it back up on the rack today and adjust it again. I think it's going to be an amazing CS car with some development.

yep...know the feeling...couldn't put ANY throttle down as it wanted to just spin and spin...:LOL: heres what was suggested to me on Nasioc on my Build Thread..

Originally Posted by solo-x

Are you actually running zero rear toe on a rear drive car? If so, that's probably a LARGE part of your over steer issue. Try an 1/8" total toe in on the rear and put the rear bar back on, see if that fixes your over steer issue.

so I am going to take his adivce...since all I have known is AWD Subies... and see what happens..


Bill

[MTeator]

Originally Posted by Scooby South

yep...know the feeling...couldn't put ANY throttle down as it wanted to just spin and spin...:LOL: heres what was suggested to me on Nasioc on my Build Thread..

so I am going to take his adivce...since all I have known is AWD Subies... and see what happens..


Bill

I came from an ES MR2 which I had to beg to rotate. I'm thinking the same amount of toe in for the rear and either 0 or slight out for the front.

[Scooby South]

Originally Posted by MTeator

I came from an ES MR2 which I had to beg to rotate. I'm thinking the same amount of toe in for the rear and either 0 or slight out for the front.

I ran 0 and 0... the front end was Planted, that is with -2.4 of front camber.. and -.5 on the rear... mine was like a top..

Bill

[MTeator]

Originally Posted by Scooby South

I ran 0 and 0... the front end was Planted, that is with -2.4 of front camber.. and -.5 on the rear... mine was like a top..

Bill

I was neutral rear and I think 1/8 out in the front.

I've only got 1.3/1.4 camber in the front (just using the smaller upper bolt) and my rear is messed up (0.3/1.9)

[Kido1986]

When you say smaller upper bolt, do you mean the OEM bolts? I thought they were limited to about .75 on camber

[MTeator]

Originally Posted by Kido1986

When you say smaller upper bolt, do you mean the OEM bolts? I thought they were limited to about .75 on camber

Yes, the OEM bolts. We also loosened the top of the strut. Pushed on it real hard and torqued it all down and that's where we ended up.

[Kido1986]

Sorry for a dumb question, any safety issues with that? I want to run competitively (eventually) locally in C-stock so as much front camber is possible. I'm still learning as I've only gotten serious about suspension modding in the past year or so on my Mazda and it's on coilovers with camberplates so it's a little easier.

[MTeator]

From adjusting it in this manner? No.

[jdrxb9]

Just a quick post to agree with MT and Bill - the car is easy to get loose. I was feeling it last weekend (6/9-10), but coming from FWD 10+ years ago, I wasn't sure if I was interpreting it correctly. This weekend (6/17), I had a pretty damn good driver take a ride along or two and then a couple fun runs and he agreed the car is loose. My RWD driving still has a LONG way to go, so I don't want to chase setup too much, but I am going to put it back on the rack and dial in some rear toe in and see how that goes before I put on a front bar.

[Scooby South]

Originally Posted by jdrxb9

Just a quick post to agree with MT and Bill - the car is easy to get loose. I was feeling it last weekend (6/9-10), but coming from FWD 10+ years ago, I wasn't sure if I was interpreting it correctly. This weekend (6/17), I had a pretty damn good driver take a ride along or two and then a couple fun runs and he agreed the car is loose. My RWD driving still has a LONG way to go, so I don't want to chase setup too much, but I am going to put it back on the rack and dial in some rear toe in and see how that goes before I put on a front bar.

yeeeep...same with me


Bill

[ubersoph]

Keep in mind, my frame of reference is autocrossing Miatas (both stock and modified) for the past 3 years. Also my setup was on stock alignment and stock sways, only change was switching tires to Dunlop Star Specs.

That said, I didn't feel like the car was insanely loose. The tail end would step out, but every time it did that I could tell it was happening before it happened, felt similar to an AP2 S2000 suspension setup. I did get faster when I didn't get the car stupidly sideways all over the place, but the car felt controllable and fairly easy to drive.

I'm thinking when I do my alignment, I might keep the F/R Camber bias pretty close to whatever is stock to keep the same kind of behavior at the limit. Also thanks again Bill for hooking me up with the camber bolts

[MTeator]

Originally Posted by ubersoph

That said, I didn't feel like the car was insanely loose.

it's not, with the stock setup I just wanted "a little more loose" and way the crap overshot it.

[Getagrip]

This past Saturday I took my BRZ out for its first autocross. I consider myself a seasoned driver as I have been autocrossing since 1996. I’ve driven mostly Subaru AWD cars in stock or lightly modded ST classings.
The car is set up with 245/40-17 StarSpecs on 17x8 +48 Rota G-Force. I have not checked or messed with alignment yet.
The pavement does not get all that warm here so I started with about 32 PSI and ended up with 30 front and 29 rear.
The car did push some going into turns but was easy to rotate from mid-way through to the end.
I’d like to get a little more front bite without making the rear too twitchy.
I finished 3rd in PAX with 30 or so drivers.

Sorry for the quality on the left side, I found a smudge on the lense.
Here is my best run.

http://youtu.be/VtUcofh2Vso?hd=1


And my best run, although dirty.

http://youtu.be/1jIckL3QBR4?hd=1


Just realized this is a stock class thread, oh well the car is basically stock.

[AX_FRS]

The July Fastrack is out and it says CS for FRS and BRZ. I thought it interesting they didn't place it in any ST class though.

[Mitch]

Originally Posted by AX_FRS

The July Fastrack is out and it says CS for FRS and BRZ. I thought it interesting they didn't place it in any ST class though.

Last week I pre-registered for an autocross in CS. Glad I don't have to change! Curious on the lack of noise about ST. Where do most CS cars end up when they transition to ST_?

[Sccabrz192]

Rx-8 stx solstice/miatas str 350z/370z not classed

[FTD]

Originally Posted by dwx

I guess the stock wheels are +48 not 42. The section width of a 225/45/17 star spec is 8.9" on a 7.5" rim. A 245/40/17 A6 is 10" but measured on a 9" rim... My guess is on a +50 rim it isn't going to fit without a spacer, with more camber.

I tried running larger diameter tires on my old SM WRX to get some more out of 2nd gear and I hated it and it didn't keep me from having to shift into 3rd most of the time. I used to autox in milwaukee which has a large lot with fast courses. Now I'm in Atlanta where things are tighter and slower.

Phil, what didn't you like about the 245's?

From my testing on 17"x7" wheels the main difference between the 225/40's and 245/40's was the 'feel'. The 245's were more spongy and slower to react, but run times were on par. The MX-5 isn't gear challenged so sticking with the 225/40 was an easy choice (63.5mph in 2nd). On a gear challenged car such as this I would try to make the 245's work. Another upside for the 245's is they will last longer before cording/wearing out.

[AX_FRS]

It looks like the 350z is classed in STR (though it makes me wonder if only the roadsters run in that?)

I don't think a car can compete nationally in a ST class unless they are specifically classed in the rules, and I know there are people on this site that would like to do just that and have been pushing to get it classed. That's why I was confused as to why they chose a Stock class and not an ST class, aditionally.

Thinking about it though, most of the modifications that are allowed for ST class have yet to be released for the cars and so SCCA really has no way to judge (aside from pulling it out of the air) just how effective the car will be after modifications.