Autocross setup

[Corpo]

Ok, so I did a little search for "autocross setup" and it didn't really give me what I was looking for, there is a lot of disscussion about what part to change for a better setup, but not much for making what you got work well. And that will be my question.

So, first, I realize I may not have the best stuff for autocross. But I'm working on that. However the local club puts on races faster then I can afford new parts, lol. It's strictly for fun events that allow us to get seat time should we actually compete. So my focus when I go is to improve my self with what I have. And beat my dad who double drives my car, we kinda push each other to improve.

Now, the parts I have..

Tokico d-specs (5 turns from full hard rear, 4 turns front. Max of 7 is full soft)
eibach pro kit springs
j&m camber plates -1.5 camber
bmr front adjustable and rear (front set to full stiff)
umi lca brackets (lca's adjusted to level with ground)
gt500 brakes with stoptech ss brake lines (rear ss lines too)
18x9 w/ nitto555 (300 treadwear) 275/40/18 front (40 psi cold)
18x10 w/ nitto555r (100 treadwear) 305/40/18 rear (29 psi cold)

I know, terrible choice for tires but it's what I got right now. Working on a set of 18x9.5's at all 4 corners and I will get a even set of rubber for autocross. That's my next big spend.

The settings I listed were what I used at the last event. The ambient temp was really cool though and my rears are almost wore out. I still had oversteer.

But now that weather has warmed up I think it may end up going back to horrible understeer like I had last year with the tires. But, the suspension is also new to this year. I have been to 2 events this year, I started on the middle setting for my front sway bar but the stiffer rear made the car really loose in the back. Since I can't adjust the rear stiffness looser, I tightened the front. Feels more balanced.

So, using what I got, where is a good place to start with the settings and what would you suggest changing as far as the settings go to combat understeer/oversteer.

And finally, any thoughts on drilling more holes in the front sway bar using a slow drilling technique with lots of lube (to keep the process cool againts wrecking it while doing it) there is room for more holes... The rear sway bar is way stiffer then the stocker..

Future plans include a adjustable rear. Possibly different front, like strano's. Rims and tires for autocross only. Change my camber plates to caster and put some extra caster and buy camber bolts to get -2 camber. Better brake pads. Techco watts.

Thanks for the advice.

 

[Sleeper_08]

Camber bolts are not suggested for auto-x. If you are running really hard then you should consider upgrading to the newer fine thread stock bolts that allow 166 ft-lb of torque.

Tighten up the Tokico's much closer to full hard unless the auto-x track is really rough.

 

[darkstar november]

i have my tokicos 5.5 turns from full soft in front and 5.25 in the rear


MM caster camber plates are a good way to go

 

[darkstar november]

also the steeda sway bars are a good choice as well. the front is adjustable with 3 holes. and if you get adju endlinks there is a trick to giving you the ability to go from 3 setting to 9 possible by adjusting the preload on the sway bar with those endlinks.

 

[Sam Strano]

To start with, I'm actually an autocrosser....

I already see issues with your setup and can understand why you have understeer, even beyond the typical overdriving many do.

You have smaller front wheels vs. rear, you have sticker rear tires than front. You have the front bar way too stiff. The adjustable rear bar would help you dial in the car better too.

You don't have enough negative camber ideally, but about as much that is prudent for a everyday driven street car.

 

[Corpo]

Yeah Sam, I know. My setup is junk, lol. But for now, I gotta make it work. Setting my front sway bar stiffer helped make the car feel less ass happy. Since I put a larger rear on. I guess I could go back to stock rear but then I'll end up with horrible understeer again..I think.

 

[Sam Strano]

The problem is things aren't well balanced... You are kind of moving from one band-aid to another. I'd also have stiffened the front bar because of the rear bar you are running, but probably not to full stiff. And the ass-happy part given what I see is more than likely right foot and lack of a good limited slip induced.

 

[Corpo]

There is only 3 holes in the bmr bar. I started in the second. Full stiff is the 3rd. It in the middle of the flat part on the bar. And there is room to drill more holes, don't think I need to. But I could.

What do you mean by having a good limited slip induced? Also I haven't spun out or anything, the car just feels like it has less grip in the back then last year. Like I can spin my rear out easily. After I stiffened the front the lessened the feel.

But what about valving on the d-specs? Think I should try softer or harder? It effects the rate at which the car's roll happens correct?

 

[Vapour Trails]

I would definitely firm up the D-specs, especially if your autocross lot is pretty smooth. Last time out I ran 3 turns out front, and 4 out rear...on a rough airstrip. On a good lot I would try 2/3.

I think what Sam is trying to say is, most car complaints, (understeer/oversteer) are induced by the driver. I know when I started this was certainly true, as I treated the brake and gas as on/off switches. Good driving requires a lot of touch, which requires a lot of practice.

 

[Thevesh]

I am using 2 front and 2 1/2 rear on a very good pavement. I regret not buying Konis though.