ep hatch

sorry if this is a noob question, but i've been looking around for a while & been finding opposite things.

to get more oversteer would you have more tire pressure in the rear or the front (in a front wheel drive car)? ... i'm thinking that more in the rear will give more oversteer, but not too sure

i've heard that less psi will give a greater contact patch but then i've also heard that greater psi spreads the threads out more to gain more traction.

this one guy running a 4th gen civic hatch told me to increase more in the front. he says he has 4 1/2 yrs of experience & his times were extremely fast. i gave him a ride during a solo2 practice and after he gave me some tips & increased front tire pressure i managed to shave off a whole second, but not sure if it was because i drove differently or if the increased psi helped

on the other hand, one of my friends went to one of those solo2 schools they offer once in a while and his instructor told him to increase the rear tire to get more oversteer. to me this makes more sense because of that greater contact patch idea.


i've only gone autocrossing 2 times so I haven't had much time to experiment. plus i never had a compressor to change my pressures between laps (had to borrow, but felt bad if i were to borrow for the whole session).


also i've heard that increased pressure in the front will give faster turning response & lower pressure (in the front) will give faster braking/accelerating response/power. is that true too?

thanks

00R101

The answer is - it depends :-)

There is an ideal pressure for a specific tire on a specific suspension on a specific track surface on a specific day. Any pressure above or below that pressure will produce less grip at that end of the car. So, if all your tires are at ideal pressures then you can raise or lower the pressures at the end that's gripping too well and get more balanced handling.

What I usually do is get the pressures in the fronts so they grip the best and then add pressure in the rear until its as loose as I am comfortable with.

The key is not too run too low. If you are running street tires than start out at 44f 40r and play from there. Since you only have a few events under your belt, tire pressures are not that important. Your times will vary more because of your changing skill than changing setup.

So, set the tire pressures so that the tires don't rollover before you run and then ignore pressures for the rest of the day. Always use the same pressures each time you run. That way you will always be working from a stable, known platform. Remember, auto-x is 90% driver. Work on the driver first!

clm

When I autocross my del Sol, I put about 42 PSI in the front and a tad over 50 PSI in the rear and get some decent oversteer; not as much as I'd like, though.

A lot of it is driver and track dependant, and like 00R101 said, just experiement.

CivicSiRacer

To add what Alan said it's a biased thing. IN my opinion if you are a newbie to autocross having less pressure in the rear (relative to the fronts) you will get a slower rotation/oversteer which is easier to catch. To get faster times eventually you want more pressures in the rear which will prevent squat (off the start line) and the tires will break away quicker, which for a novice will be hard to catch.

tnord

remember your front tires will heat up more and reach a higher "hot psi" than the rears will. so even if you want your pressures to end up even, you'll need to stagger them a bit........especially you FF guys.

matt j

i noticed at the last event my car rotated alot better with 40f 30r pressures, i usually ran at like 34f 36r, the car didnt push as much and it was holding the slolom very well (except for the fact that a course worker jumped in front of me).

Vracer111

I run about 35psi front/ 27psi rear on my BFGoodrich KDW's...of course I have a Toyota Tacoma though....too much psi in the rear equals horrible traction issues.

B16b2b

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by matt j &raquo;</TD></TR><TR><TD CLASS="quote"> the car didnt push as much and it was holding the slolom very well (except for the fact that a course worker jumped in front of me). </TD></TR></TABLE>

haha.