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gen3rx7 07-02-04 04:53 PM

BFG autocross tire pressures
 
I'm doing an autocross tomorrow w/ new BFG TA KD's.
Anybody ran these on an FD (stock)?
Just looking for a place to start for tire pressures.......

Any help would be appreciated!

Thanks.

Fatman0203 07-02-04 06:22 PM

Are they BRAND new, you should heat cycle them a bit.

DamonB 07-02-04 08:52 PM


Originally posted by Fatman0203
Are they BRAND new, you should heat cycle them a bit.
Aren't those street tires? No heat cyclig necessary.

gen3rx7, take this with a big grain of salt as I have not run those tires. Try 38 front and 34 rear and go from there. You want to scuff about a 1/4" down the sidewall. Too far add air, too little decrease air.

Fatman0203 07-02-04 08:57 PM


Originally posted by DamonB
Aren't those street tires? No heat cyclig necessary.

gen3rx7, take this with a big grain of salt as I have not run those tires. Try 38 front and 34 rear and go from there. You want to scuff about a 1/4" down the sidewall. Too far add air, too little decrease air.

I thought it was all tires, since it makes the compound go through a cycle, I heard if not it can chunk off. Yet you could be right.

I know there is a site I think by Petit but not 100% sure that says pressure levels for under or oversteer and etc etc. I rebooted by comp so I lost most if not all of my favorites.

gen3rx7 07-02-04 11:10 PM

They're pretty new, about 200 miles of not too agressive driving. I'll be running on concrete if that makes any difference....I know they will be much better when broken in.

I'll try the 38/34 recommendation as the car tends to oversteer a little... I'll probably not be too agressive on early runs to see how they handle. I will be running Sunday also, so maybe 5 runs in the heat (forcast for 95 degrees) might cycle them tomorrow....

Thanks for the advice!

Fatman0203 07-03-04 12:13 AM

Search around for tire pressure, and you should find the website im talking about.

Carl Byck 07-03-04 09:53 AM

Those are pretty stiff, I would say 32 HOT. since it's an AX I would start at 32, and see where your pressure goes, keep letting air out until you stay at 32 after the run. So use the chalking as your first indicator, and the pressure as your second. Once you get those right, you can play with the pressures, or shock/sway bar settings to get the car neutral. Just remember, understeer, make the front softer, oversteer, make the rear softer. Also after 2000 miles they are "cycled". Take care abourt your pressures, too high, or too low, and you will have ruined some very pricey(but good) tires. Carl

gen3rx7 07-03-04 11:05 PM

I ended up running 39 front and 37 rear which produced a good wear point on the side. I assume that as the tires wear in I'll be able to lower pressures somewhat. I did OK today, I believe I took 2nd behind a 2004 Z06.

Thanks for the advice guys!

BTW, no chunking or problems on the new tires.....

Fatman0203 07-04-04 01:16 AM


Originally posted by gen3rx7
I ended up running 39 front and 37 rear which produced a good wear point on the side. I assume that as the tires wear in I'll be able to lower pressures somewhat. I did OK today, I believe I took 2nd behind a 2004 Z06.

Thanks for the advice guys!

BTW, no chunking or problems on the new tires.....

Congratulations, did you find the site I mentioned? Mind telling us what your suspension set up is. Congrats once again, thats really good.

gen3rx7 07-05-04 03:56 PM

I haven't checked the site yet....As for setup, none really. Since I bought the car 2 years ago I have done nothing to the stock suspension. I Know I would benefit from a good alignment (camber and caster are factory settings still), sway bar (and upgraded mounts) and possibly upgraded shocks.

I really am not planning on doing much racing with the car as it's in near showroom condition with only 36 K original mi.. It's just fun once in a while to do an autocross or track event to let it do its thing.

Thanks again for the help!

Bob

Fatman0203 07-05-04 07:57 PM


Originally posted by gen3rx7
I haven't checked the site yet....As for setup, none really. Since I bought the car 2 years ago I have done nothing to the stock suspension. I Know I would benefit from a good alignment (camber and caster are factory settings still), sway bar (and upgraded mounts) and possibly upgraded shocks.

I really am not planning on doing much racing with the car as it's in near showroom condition with only 36 K original mi.. It's just fun once in a while to do an autocross or track event to let it do its thing.

Thanks again for the help!

Bob

Ahh that explains alot. Your shocks, bushings, and all suspension are still in great condition (unlike mine with 140k miles?!) So that helped you alot. Congrats once again, I hope to fix my suspension one day and reach that level.


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