Tire Pressures for Hoosiers (ITA CRX Si)

[grimmer]

I run my 88 CRX Si on 205 Hoosiers at 36 psi. Once the tires are hot, I like the feel of the car. But it takes almost 2 laps at a 2 mile course to get the tires hot- kinda sucks at the start of a race. I've talked to other guys running as low as 30 psi (and running faster than me) and am thinking of trying something lower. Is it right to think this will get the tires slipping more so they get hotter sooner? I know Hoosier says too low a pressure limits ultimate grip and increases wear. What's everyone else doing?

Thanks,

John Grimmer

[Tom Blaney]

I run 33 on my 90 CRX, but a lot depends on your driving style. However 36 might be a little too high. Heep in mind that a pound goes a long way...

Tom Blaney
ITA # 26

[lb2]

I run 37 on the front and 35 rear on hoosier and this is what I have been told to run by one of the best CRX driver in the SOuth Tom Fowler from OPM Motorsport.

Louis Boustani
ITA CRX 2

[B Breon]

I second Louis's comment, I run 36 front and 35 rear, have pretty much all year. Nice wear, good temps, car feels good, at least for the setup I am running.



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Brent Breon
Cendiv ITA #26
www.360racing.com

[USGUYS]

When we first started running in IT we ran cold pressures in the area of 35-36. The car was very prone to locking up tires under braking. Lower pressures seemed to work better.
Since Road America and Blackhawk Frams put a lot of pressure of the left nfront we tried staggering the pressures.
We settled on 27/LF 28/RF 29/LR 30/RR. The hot pressures is 35 in all four tires. The car is loose for the first lap, so some caution is needed. Try this. I think you find it works if you have your corner weights right.
We have run 2:46s at RA and 1:23s at BHF.
Tony Machi
Milwaukee Region
ITA CRX 96

[lb2]

Again I run 37 front and 35 rear and the best I did at Road Atlanta is 1.44.70 last ARRC, Tom Fowler from OPM Motorsport runs the same pressure and last ARRC we was in the high 1.43. at Road ATlanta.
Trust me stay with 37/35.

Louis Boustani
ITA 2 CRX SI

[Jon Nelson]

These are HOT pressures, right?

[lb2]

37 Front
35 Rear
cold pressure.

Louis B.

[USGUYS]

Louis
What are the pressures hot? What kind of spring rates do you run? I ran 46s at Atlanta, but I need a lot more track time to get quicker.
We run 450/700 springs with swaybars ft and rear.
Do you find that the tire go off at end of a session? I have not found any unusual tire wear either.
I can't run the ARRC, but I will try the higher 37/35 next year. Can't stand still the Nissans are coming.

[Tom Blaney]

Originally posted by lb2:
37 Front
35 Rear
cold pressure.

Louis B.

Louis:

I would be interested in knowing what your hot pressures end up to be. I run a lot less pressure, and have not run my 90 CRX at Atlanta yet?

Tom Blaney

[grimmer]

Thanks for all the info and discussion. I'll add a little more of my own. I just received this from Hoosier:

---------------
John,

About your air pressure, the 36 psi cold does sound good. Running 30 -32 psi
is too low and can cause the tires to roll over and wear the edges out
prematurely. Also, rotate your tires to help even the wear out as well.
I hope I have helped.
- Jeff Speer, Product Manager
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Also at my last race on Sept 30, on advice from Dave Volante, I ran 34 psi front and 35 psi rear cold. The tires seemed to heat up a little quicker and the difference from front to back made the car less prone to oversteer. It seemed like the cornering limit was slightly lower but much more forgiving. I was able to bring it closer to the limit without risking a spin. My best lap at Blackhawk Farms with this setup was 1:26.3, down from 1:27.2 previously. Turns 3 and 5 were definitely faster, but Turn 3A required some trailbraking to rotate the car.

BTW, Tony, I'm racing Jake Krizan's old car with Midwestern Council.

John Grimmer
still #28 Yellow

[lb2]

Hot pressure runs around 43/41 after a session, I am running 700 spring in the back and 500 front no sway bar at all on Koni double adjustable Race valved shocks.
As for tire going of at the end of session, I run my car loose in the back so at the end it is neutral so really I have no problem with tire at the end, wear is even also with running -2.5 camber on rear and -1.75 Front.
Arrc looks that is going to be not a big hit this year, all the guys that I know are not planning to run due to the bad economy, Nissan will be here of course and that is his last season since Bob Stretch is going to Speedvision Challenge next year.
Louis Boustani

[USGUYS]

John which one of Jake's car are you running. I bought my car from him, but crashed it at Road America. Much of the same stuff is in the current car.
Sent me an E-mail at [email protected].