Hey guys, I'm looking to see what kind of tire pressure's you all are running. An aggressive setup preferably.

I just got some Sumitoma HTR Z III's on the car and I want a good baselinge to start with. I was experiencing some drastic understeer right before my BFG G-Forces popped...

 

do 34/ 32.

 

What suspension mods do you have? What are your alignment settings? Under what conditions were you having understeer?

 

I have the same tires, plus a Whiteline rear anti-sway bar (24mm), a Carbing chassis lower arm brace, RS trunk brace, front and rear strut tower bars, and Swift springs.

Front: 38 psi (street) / 45 psi (autox)
Rear: 35 psi (street) / 43 psi (autox)

 

With understeer I up rear pressures. Ex: 34 front / 36 rear.

 

You know when the tires are hot the psi go up right? going 45 psi is not safe. and running high PSI like that gonna eat ur tires up.

 

at the autox today, i noticed if i lowered my back pressure it would push through EVERY corner. put it at 38 in back, and 36 in front. still not as good as i would have liked to have done, but it didnt push as bad anymore

 

This is the combo I've found to work best at autocross to prevent the tires from rolling over. Why do you say it'll eat my tires up?

 

Can move up more then - this is what we all do to tune for the surface.

 

You seem to be working hard to impress this crowd. Its ok. But we have a lot of knowledge and professional experiences (well, few of us) with tires, susp, brakes.

I think you are confusing AX and track tire pressures. In AX, you can start with a high psi. Tires don't heat up that much.

But on the track, you know that on the track a cold psi of 35 will easily go to 45 psi hot? Tires work great still.

 

Auto Cross 32R/35F
Drag 19R/22F
Street 29R/32F

245/40-18's

 

Not really trying to impress anyone since I don't know most of you guys in real life nor I am trying to act like I know it all. I was just asking him a question.

I do not autocross and do mostly track and canyon runs , so yeah those are based from my observations.

Well it's good to know something new. Thanks for the comment.

 

Before the OP's question can be answered, we need to know what rim size and tire size.

As an example: I run my stock Advans (235/45-R17) at 32-34 psi (cold). In contrast I run a set of Eagle GS-D3 (265/35-R18) tires at 38-39 psi (cold).

l8r)