The Autocross thread. Got questions? Get them answered here!

[ATaraxias]

TY!

[strat61caster]

If the FP has a cat all you have to do is swap off e85 and you'll be STX legal. E85 and/or no catalytic converters at all puts you into CSP or SM, both classes allow non-street tires (Hoosier A7) so you won't be competitive with Bridgestones but that won't bother anyone.

Per 3.6 you can only run E85 in Street or Street Touring if the car is designed for it:

3.6.A Fuels comprised of more than 15% ethanol may only be used when specified by the manufacturer (e.g., in the owner’s manual for flex-fuel vehicles).

CSP should be slower than SM, but just head out and have fun anyway.

[jay_reef15]

I got a quiestion i have a Personal Grinta steering wheel in my brz would thst be able to pass inspection for autocross?

[14stu]

Originally Posted by jay_reef15

I got a quiestion i have a Personal Grinta steering wheel in my brz would thst be able to pass inspection for autocross?

For now it should be legal, as long as it is the same weight as the OEM (with mounting hardware).

There is talk about no longer allowing aftermarket steering wheels because of the airbags (they could change the rules as early as next year so that you will no longer be allowed to change or modify anything that had an airbag like seats and steering wheels).

[cjd]

Note, the steering wheel allowance is for ST* not Street (CS/DS) or SSC.

Whether it passes tech is not itself related to whether it is legal, only whether it is safe.

[jay_reef15]

Its not the same weight as the oem since it dosent have air bag on it i still have al my oem parts i think i am going to get a new steering wheel that has the air bag and is alcantara

[Qc86]

I did my*first autocross of the year recently and i have a couple question to solve my problems,

First here is my actual setup:
Fortune auto 500 with 9k/8k swift springs
Grimmspeed strut bar
Whiteline LCA*
Nitto invo 245/40/17 tires
And my alignement is set to -2.5 / -1.8 camber (cant remember caster and toe)

Now here's the thing:
My car has tons of grip in the front but it tends to oversteer in slaloms or when im in a quick turn.

1. I know i dont have the best tires i just got them because i had a crazy deal on them. What would be the best tires for autocross and DD? (I cannot have 2 sets of wheels and tires)*

And should i upgrade to 255 instead of 245?

2. Should i add a little bit more camber in the rear or play with the toe? (My car is a DD lets not forget about that)
My camber is already maxed out front and rear, i think i would need adjustable toe arm to achievemore camber in the rear if i need to.

3.Should i downsize the rear swaybar for like a Mann engineering? I have a 2017 so bigger swaybar than previous model

******

[strat61caster]

1. Shot in the dark but Hankook RS-4 would be my guess, size will be preference, buy what's cheaper and focus on seat time, use the Nittos for awhile longer, low grip teaches you good things. There are a few other 200TW tires that could fulfill the same purpose. Give up a run and have an instructor drive your car with you sitting shotgun, I learned a lot more doing that than any passenger shouting any advice at me possibly could teach. Videos are useful for comparison too.
2. Toe in may help, take it to a different shop if they're saying you're maxed, you don't need toe arms and the Whitelines should be able to get you over -2.5 in the rear with stock toe arms. Every nationally competitive 86 STX car has stock toe arms, I've heard as much as 1/2" and run as much as 1/4" but that's a work in progress on my end.
3. Just try detaching it first, see what happens, no cost tuning, can probably do it in between runs.

A good driver can make any car feel ok, a bad driver can make the best car in the world feel like crap, don't start throwing money at the car when the nut behind the wheel can have the biggest effect. You may be unsettling the car and creating problems not related to the way it's set up. Damper adjustments also may be playing a part in what you're feeling as well, maybe softening the rear will get you what you want.

[14stu]

A second set of wheels and tires often pay for themselves due to reduced wear on the race rubber. You can store them just about anywhere. I used mine for a "grownup" racecar bed for a while where they were my bed frame, and you could throw a plywood top and cloth over the top to make a table. Or you can just stack them in a corner since they take up as much space as a large trash can.

[Qc86]

Originally Posted by strat61caster

1. Shot in the dark but Hankook RS-4 would be my guess, size will be preference, buy what's cheaper and focus on seat time, use the Nittos for awhile longer, low grip teaches you good things. There are a few other 200TW tires that could fulfill the same purpose. Give up a run and have an instructor drive your car with you sitting shotgun, I learned a lot more doing that than any passenger shouting any advice at me possibly could teach. Videos are useful for comparison too.
2. Toe in may help, take it to a different shop if they're saying you're maxed, you don't need toe arms and the Whitelines should be able to get you over -2.5 in the rear with stock toe arms. Every nationally competitive 86 STX car has stock toe arms, I've heard as much as 1/2" and run as much as 1/4" but that's a work in progress on my end.
3. Just try detaching it first, see what happens, no cost tuning, can probably do it in between runs.

A good driver can make any car feel ok, a bad driver can make the best car in the world feel like crap, don't start throwing money at the car when the nut behind the wheel can have the biggest effect. You may be unsettling the car and creating problems not related to the way it's set up. Damper adjustments also may be playing a part in what you're feeling as well, maybe softening the rear will get you what you want.

Thanks for the advice, i head the BFG rival s 1.t arent bad but i dont know about how long they last.

Next autocross event ill try to have an instructor drive my car and will ride shotgun for sure, wish i could have another set but all the events a 5hrs drive and i cant bring the second set with me when im going.

I will try detaching the sway bar.. no risk doing it right?

And i tried playing with my damper, it did a difference when i went full soft in the back i saw it was more grippy.

And my wallet dont really care throwing money at my car for things i dont need


Thanks for the feedback!

[Zoid]

Are SPC LCA's safe for autocross? They look awfully thin.

[cjd]

Originally Posted by Zoid

Are SPC LCA's safe for autocross? They look awfully thin.

Safe? Yes. Not much different than stock. Stock bushings in them aren't legal for STX though. You can get them with a legal replacement bushing.

[Zoid]

Originally Posted by cjd

Safe? Yes. Not much different than stock. Stock bushings in them aren't legal for STX though. You can get them with a legal replacement bushing.

I read that in a much older thread while looking around and that a lot of people seem to go for Whitelines instead. I think I read those were legal for STX but I also read that they're noisy where as the SPC's aren't which is a big factor in which I end up choosing since this is my DD. Do you know anything about this? Where would I get the SPC's with the bushings you mentioned and would that affect the noise?

[strat61caster]

Originally Posted by Zoid

Do you know anything about this? Where would I get the SPC's with the bushings you mentioned and would that affect the noise?

I think I've only seen FRSport offer it installed.
https://frsport.com/dif-10595-adjust...uring-fr-s-brz

Bushing on its own:
https://diftech.com/products/street-...r-s-brz-445911

I don't know for sure, but I think this would be noisier than most solutions, delrin is basically solid plastic, a softer bushing like what Racer-X used to offer would be more DD friendly but I don't know if there's anything like that on the market still.