We corded a front Kumho today on a friends GS-R, so tommorrow we will have to run 205/50-15 Falken Azenis and I really have no idea what good pressures to start with. I did a search and got a thread on road racing air pressures, but thats a big difference.

Anybody have recommendations? The car is a 95 GS-R with Tein SS Coilovers, header, SuperTrapp, etc. The surface is pretty abrasive concrete.

Thanks in advance.


[Modified by Brett@SoloRacer.com, 12:45 PM 7/6/2002]

 

I just did a huge trial and error on this last weekend at an auto-x. I don't have anyone else in my class so I didn't have to worry about "the competition." We had 6 runs total (2 run groups back to back so it seemed like one big group) which is why I wanted to experiment in the first place.

I started at 42f/45r which was just ridiculous! The car was all over the place and I couldn't control it to save my life. Long story short, the more I took out the better it handled and the cooler the tires were after each run. I cooled the tires with a spray bottle after each run (one of the vets there recommended that one) so I could really tell with my super-precise pyrometer (my hand) how hot they got

I figured out that my car (with 205/50/15 Azenis and Buddy Club coilovers) loved 34f/37r. As it turned out, the top STS driver there also uses these tires on a Celica GT-S and uses almost exactly the same pressures (also with modded susp.).

Hope that gives you some sort of starting point anyway. Good luck tomorrow

 

Well, just came back from the SD auto-x today. As usual, I ran the Integra in STS down in SD. I'm on 215/45R16 Azenis with 16x7 SE37K (TEIN HA - full stiff in the rear and mid way in the front). I ran with 40f/50r, nice rotation and the tires didn't roll over too much. They just rolled over to where I wanted (barely at the tip of the wear bar arrows). BTW, I won the class with that setup. The second place was a Sentra SE-R also on Azenis (195/60R14), but he ran with 50f/38r. However he's on stock springs with (I believe) KYB shocks.

 

That seems like crazy high pressures to me, I just finished my azenis and ran 36f 39r, anything over 40 and they slide around like crazy. this was with the 14's. I don't know about the other tires.

 

I was real happy with 36/36 on concrete at Griffis AFB in NY.

My car has a relatively mild setup though. H&R OESport springs (a little stiffer than ITR) and a ST 19mm rear sway bar.

 

I think your Buddy Club coilovers kinda help you to use that air pressure and have no rubbing on sidewall.
Cus the last time when I still using my Falken at AutoX, I've to use 38F/ 41R (cold), otherwise the tires may rub the sidewall.

Btw, can you tell me what setting you're using on the Buddy Club when you at AutoX??
THANKS

 

38/36 (hot) at the track for me... worked out to about 31/29 cold. Anything hotter they got really greeezy and didnt feel as good. For a street tire, they like very low pressures.

RJ

 

For me on my 2000 Civic Si: 39f/35-34r HOT.

 

37-39 front
31-34 rear

both temps hot, and depending on surface.
205-50VR15 Falken Azenis with ~-1.2 degrees camber in front.


[Modified by PseudoRealityX, 4:02 PM 7/7/2002]

 

My last three autox events on the Azenis I got a very experienced autocrosser to drive the car with me specifically to get my new tires pressures and suspension setup well.

As with all street tires I've ever ran on, higher pressures (even on the azenis) is the only thing keeping them from rolling on the sidewall too much. We tried different pressures and we ended up running 42f 47r. Any less up front (we did try 40,41) would start rolling the front tire to much to the sidewall. Any higher in the back and it didn't seem to make any more difference in rotation, while any lower and the car would not turn as well. For autox a lot of people start running maybe 1-2 below their target pressure (hot) on the first run and then bleed it down after every run to keep it at your target pressure. Otherwise you might waste more that half of your runs just in getting up to your temps. Keep in mind this is on a car 400+ lbs heavier than yours, with about 1.2 neg camber up front and 1.6 in the back. So consider the other people's advices first. Good luck!

 

We ended up running 38 front and 36 rear. The car had alot of push with that setup though, and I was a little dissappointed. The car still needs alot of sorting, so it could have easily been other things besides the air pressures.

A friend of mine running an E30 M3 in STX runs 33 all around with his Azenis! He tried higher pressures, but got alot of push that way. I realize thats a totally different car though.

Thanks for the tips everyone

 

I've had no roll-over issues, but then again my car weighs in at ~2300 lbs, and i have about 1.5 degrees of camber. 33 does seem very low though. 36/38 (hot) i bet would be a pretty good autocross setup. Funny, those pressures are a tad lower than what i ran my Victoracer's at. Strange...

RJ

 

Try running 5 more psi in the rear next time just to see how it is. The pressures you ran with the azenis were the pressures I started out with when I had the V700s and with 38f and 44r the car was rotating significantly better. Do a degree this works the same as with street tires.


[Modified by Hracer, 7:23 PM 7/7/2002]

 

Yep, thats what we were going to try, but ran out of runs. The car still has the stock rear swaybar, so rotation is pretty tuf to get. It handled real neutral on Saturday with Kumho V700's (not sure what the pressures were), but today the car was pushing like crazy and I hated it. I think the guy might put a rear swaybar on next, and I'm pretty sure he's going back to Kumhos and DSP. He'll be getting 225 fronts and it should work nicely like that.

 

I'm with Mike and Jesse on the front rear combo in my Civic DX. These have a very stiff side wall so with 38psi in the front I have very little if any roll over with my 205/50-15s.




[Modified by Civic242, 9:29 PM 7/7/2002]

 

My instructor at the track for June Jam was questioning my use of relatively low for street tire air pressures as we went out for the morning session Saturday. I went on what i read here, and sho 'nuff they worked great! 31F/29R cold. I was amazed that a street tire has sidewalls that stiff. They were almost as hard to mount (on 6" wheels) as my Kuhmo Ecsta V700's, which were 225/45(!) on a 6" wheel (!).

RJ

 

After running the Azenis all year long, I'm finaly finding out how to set them up. I used 36F/28R and was able to get pretty good rotation. I have stock sways, but stiffer springs 400F/450R so that will help a little. A stock R was running the rears as low as 25psi to get rotation. I would try reducing the pressure in the back as opposed to adding. I tried higher pressures all the way to 48psi and it did not help. Only reducing the rear pressures was I able to get a good handling car.

 

I had my first weekend autocrossing the bone stock ITR in STX with the Azenis. Through about 12 runs I've got tire pressures that work very well for my car. 35F, 25R. Mind you this is very sticky concrete and the only way I could get the car to rotate was to lower pressures to obscene levels. fwiw - I started at 31 in the rear and went down till the car would turn.