Whiskey11

I want to say when my car was stock the tire pressures I ran where 38F/35R on the stock KDWS tires. With the Star Specs I have it is 31F/32R and the scuffing on the sidewall is pretty spot on and the car is very willing to change directions. Could be a number of things causing the fronts to be lower than the rears, but the pressures are way lower than most of the local guys running the same tires on different cars who are up in the high 30's.

jlwdvm

Ran this weekend on a tricky (for me) course. Fastest in my class went a 74+ (cobalt ss) and I was at a 77+. I ran in STX because nobody can tell me exactly what class I should be in. In a field of 36 cars, a great driver in an Audi TT turbo all-wheel drive was at a 69+.
I set my tire pressure at home, since I don't have a pump to adjust it at the track. 25 front and 30 rear. Tires gained over 5# each after heating up with ambient temps in the 90's and hard driving. Set my front sway bar in the middle hole and the rear in the stiffest hole. The car will oversteer with too much throttle, but seems fairly neutral. Koni's set to full firm in front and 1/2 turn out in rear. I tried going more firm in the rear, but the car didn't seem to like that. I know the car has a lot more in it, if I can figure out how to adjust it, and more importantly how to drive it!

Norm Peterson

Too much rear tire pressure, probably not enough front.

To a point, cornering response improves with more pressure but mechanical grip goes up with less pressure. I think more people are running the pressure stagger the other way with the fronts higher.


Norm

Sam Strano

3 big issues.

1. Air pressures, backward (and not enough). I don't recall recommending those pressures or the rear be higher.

2. Front bar should have been middle, rear either soft of middle to start. Full stiff rear, full soft front is not what I recommended.

3. The stock tires aren't great, and those other cars might well have been on something as good and likely better than you were. This car is very tire dependent for speed. You have a heavy car, it needs grip to work. Light cars better get away with less grip. We don't.

jlwdvm

I was trying to make the car neutral to just a hair oversteer. I started the year with both front and rear bars in the middle hole and had all tires at 35#. This weekend I set the rear bar in the closest hole and had the air pressure a little lower in the front to help take out some understeer. I know that total air pressures were probably too low, but I remember someone saying: "you can't really go too low". I know my tires aren't the greatest and that they aren't R compound tires and that my car is heavier than most with a longer wheel base. Just trying to learn and I'm sure nothing replaces seat time, but my free time is limited, as well as local events.

BlackBetty

In my opinion you shouldn't trust that person's advice. On street tires in general you want higher pressures than, for example, R-compounds. I run the Bridgestone RE-11 and use about 38 psi all around. It's probably a bit on the high side but I found this to work a lot better than low 30's.

Sam Strano

Yeah, I don't know who said that but I'd file it under "crap you read on the internet".

Was the car better?

jlwdvm

"Also more rear tire pressure, or maybe (not always you can't run too low) less front pressure." ....from post #2. I ended up with 30 front and 35 rear hot pressures. Maybe I took your advice a little too literally? The car was improved at the last autox as compared to the previous one with different settings on sway bars, tire pressures, and shocks. There was only 1 time that I can remember where I pushed the front too hard and I got that vibrating-tire screeching sensation/sound going into a hard corner.

Sam Strano

You misunderstood.... I meant you can't always run less pressure, you can't run them too low. I wasn't clear in how I typed it, that's my bad...

jlwdvm

With my exhaust: Corsa extreme axle backs, I can't get my rear bar in the softest hole. It is currently in the stiffest hole and my front bar is in the middle. Should I put the front bar in the stiffest hole and return the rear bar to the middle? What might this do to the car? Thanks for all the info.