Tire pressure in road racing??

[Indiefab]

This is for you guys that do autocross and road racing on street-legal tires. What pressure do you run?

I am about to finish off my stock Goodyears and replace them with Nitto 555's (not DR's). I'm sticking with stock size and Bullitt wheels. I currently have stock suspension and brakes that needs upgrading badly to keep up with the stinking WRXs and RX-8s.

Do you run them slightly lower pressure than street for better grip or keep the pressure a little high to help with sidewall stiffness?

I'm doing a high-speed touring series here at Hallett in Oklahoma. Track is 1.8 miles, 10 turns, extremely technical. My max speed on the front straightaway is ~95. The rest is left/right/brake with several short straights into tight hairpins that really make the tires squeal. The series is basically a practice session- no passing in corners, spin too many times and your're out, etc... It's really to have fun, learn how to drive and see if we want to go further.

I noticed after my first four sessions on Saturday that overall my tread was in pretty good shape, despite already having 30K miles on them. However, the very outside edges had taken quite a bit of wear, much more than before Saturday. I was running 30-32# of pressure and it looked like the tires were rolling over too much in hard cornering.

I noticed one very fast Cobra running Goodyear F1 GS-D3s. I have decided on Nittos mostly for cost reasons.
Any suggestions on pressures, especially on Nittos?

 

[No Control]

I'll probably get flamed here, because everyone thinks that Nitto is the ****nit, but.

If your serious of going road racing/autox'ing/open tracking and staying on your same daily driven tires, go with either Sumitomo HTRZ II's or Yokohama AVS ES100's. Much better tires for what you're thinking of. I've gotten 20k out of a set of the sumo's and just switched to the yok's.

If tire wear is not too much a concern, and you live in a climate that isn't too rainy, go with Kuhmo Victoracers. Best tire for autoxing and open tracking.

The best advice is to buy a set of lightweight wheels and put either the victoracers or a set of Hoosiers on them. That way, you don't have to worry about tire wear. And last but not least, an hour of seat time is worth more than a thousand dollars in mods...

Take it from someone who's done autoxing for a while, and open track'd just as much.

 

[4.6_02_Black_GT]

IndieFab....

hehehe funny you should mention Goodyear F1 DS-G3, thats what I choose to run on my car, after a lot of research you just cant beat this tire for wet and dry performance. They are hands down the one of the top 3 rain tires you can buy, and are equally high marks for dry traction. I run 275s on all 4 corners

I'll have to go down to the car to read the sidewall but maximun psi is 51 to 55 psi(yes 50+). Here in Charlotte they where going to let us on the road course and required all tire pressure to at 40-41 psi( I guess they didnt want anyone rolling their sneakers off). 40 psi range is what I have heard.

 

[Barnaby]

Start high (40psi-ish) and drop it as needed.

 

[Indiefab]

IndieFab....

hehehe funny you should mention Goodyear F1 DS-G3, thats what I choose to run on my car, after a lot of research you just cant beat this tire for wet and dry performance. They are hands down the one of the top 3 rain tires you can buy, and are equally high marks for dry traction. I run 275s on all 4 corners

OK, quit your bragging.

Thanks for the opinions. I'll try 40-45# next time. I think it will give me more predictable traction slip in corners.

Anybody else?

 

[4.6_02_Black_GT]

Indiefab..sorry

I saved a long time for them, so I like talking about them.

 

[racegirl1]

I also run with Nitto 555 RII these are not the DR'S although they have the same tread pattern obviously the side walls are stiffer then that of the DR. The tire pressure I run with the Nitto's are about 35 PSI in rear and with the Falken's I run about 36 PSI in front. This seems to work great for me in weather ranging about 100 degree's.

I run the Nitto's in the rear because they only make the 275 X 40 for the 555 RII. I run the Falken Aziens in the front with stock application 245 X 45. The Nitto 555 RII is a great choice and they stick like glue. However for a daily driver you might notice that you will wear these out quite fast as the treadwear is only rated at 100 very sticky tire. If you are staying with stock 245 X 45 all around then next time go for the Falken Aziens. Solo2 and PCA and SCCA use the Aziens for all Auto-X events. There treadwear is a 200 rating and they will last as a daily driver tire as well.

Happy Auto-X and Road Racing days ahead. Its a blast, I sign up for both every chance I get. Currently going to run at a track in Rosemond, CA called Willow Spring International Raceway its considered the fastest track in the West about 2.5 miles long. Can't wait took Friday June 4th off work just to drive the two hours to get to the track run all day and come home that evening. Anyway thanks for reading and again happy motoring

 

[loav8r55]

One of the best ways to check if you have the right pressure is to check the tire with a hydrometer. It will check the heat in the tire. You want to try to get the tempreture as even as possible on the outsides and the middle. pressure varries too much depending on the track temp.

 

[007]

One of the best ways to check if you have the right pressure is to check the tire with a hydrometer. It will check the heat in the tire. You want to try to get the tempreture as even as possible on the outsides and the middle. pressure varries too much depending on the track temp.

I just use a Tricorder, then beam the data up to Spock and Bones and wait for them to tell me what pressure to run.

 

[bads]

ha

When i was on stock goodyears and stock suspension i started at 38 all around, but usually end up running 36 up front and 37 in the back. I like to tighten the back up a little bit and take some plow out of the front. Once you get some seat time in you'll know more where to put the tire pressure. Anyone else run MidOhio much?