Entered my second ever Auto-x last weekend.

And somehow pulled off a win in B stock !!!!

Driving an all stock 05 w/ the original dunlops. (12 k miles on them)

I ran the pressure at 38.5 - all four.

The 8 rules!!!!!!!!


results:
http://www.scca-susq.com/results/200...axresults.html

 

Congrats on your win. Guess Tim is out of town this past weekend. Philly SCCA will give better competition if you really want to step up the game, and he's not around.

Job well done on street tire nonetheless!

ps. Tim's "05MazdaRx8" on the board. We ran a few times in the past.

 

He He .... yes I'm fully aware that would have not won if Tim was there!! - He was at the last one; and he was smokin' fast. Perhaps he'll be at the farmshow.

 

Haha not to bad man, not to bad @ all. I just finished my second event and placed 1st for the fastest raw time in novice class!!!

 

[Luke blows up his first TIE fighter]
Luke: Got 'im! I got 'im!
Han Solo: Great, kid. Don't get cocky.

http://members.tripod.com/~RodneyT/cocky.wav

http://cocky.ytmnd.com/

 

I am doing my first autocross with the 8 tomorrow and searched for a good starting tire pressure. OP. thanks for including that info . . . I had a feeling that would be the ballpark. It will be a hot day so I'll probably start with 38psi cold all around.

Wish me luck!

 

With a stock alignment this is a good starting point, but with a more agressive aligmnent , I have -1.2 camber front, -1.5 rear I've found that my pressures are down to 35psi front and 32psi rear. Also these are hot temps, not cold. Brought the times down by 2.1 sec to 48.6 on a 50.7 avg., 44.08TTOD course with new alignment and temp tweeks. Still running stock everything.
When i was running stock alignment, I was using 38psi front and 35 psi rear, HOT. I was getting +3 psi average with 88-90degree day. So my cold tempratures were 35 front, and 32 rear to start, then adjusting as necessary after the first run to get the tires to roll where i wanted and correct any handling issues.

 

If you have the RE040's I would reccomend a drastically lower cold pressure. The sidewalls on that tire are really stiff and I found the 32F 30R was the way to go on those when I did a few events before I got my R comps

 

I'm on the stock Dunlops. The sidewalls are pretty stiff, but I have no idea how they compare to the Bridgestones. They are nothing like the RE070's that my STi came with.

I do have a good alignment (front -1 camber / 7 caster / 0 toe; rear -1.5 camber 1/16" toe in). I'll have my pump with me, but its still easier to remove pressure quickly than to add it. My first run will be a learning experience anyway.

At my last HPDE track day, I was targeting 40psi HOT, and by the end of the day, I was down to 32-34psi cold. Hot day with much longer run times, obviously. I have a hard time understanding how the tires will actually heat up enough to gain pressure on the autoX course with such short runs, but I'll find out today.

Thanks for the suggestions . . . I'll post results later!

 

Concur with Cosmosmpower, After a practice day yesterday, I'm down to cold, 32F, 29 rear. Be ready to pull 5psi at a time to make best use of your runs and get the max out. Good luck.

 

OK, so I think you guys were right about the pressures. Having said that, today was not the day for me to worry about that. Not only was it my first Autox, but it rained half the day so course conditions changed alot. I was looking for traction all day.

Early on, I had a lot of oversteer on throttle. Lowering the rear pressure to 1 psi below the front made the car a lot more neutral overall. I kept bleeding pressure over the course of the day, and by the time I got home and cooled everything off, they were at 36psi all around (the fronts were 1psi higher when hot, 38psi vs 37 in the rear.) I think I will start with 35 cold all around (which seems to give a higher hot temp on the fronts) next time and work from there.

The car was a lot of fun. My best time was a 40.7sec, with the fastest times of the day in the mid to upper 30's. I did not use the car to its fullest potential. I have a lot to learn!

Some pics below . . . also check out my brother's bone stock '84 GTI

 

You now need to start looking at how far you are rolling over to the sidewall. Depending on how much you care about tire life, you would like to see the tire roll to the little triangles that are indicators of the limit for normal use.
If you were searching for traction on a course that short, I would guess that you needed to seriously look at lowering to get max grip. Again, depending on the alignment, the course speed etc., your going to have to tweek the pressures to give you the best performance based on the sidewall indications.
Be aware too that as you get better and are able to push the car more, you will have to continuously adjust for that and the track temps.
In the end it cost you nothing other than time and can be the difference between a couple seconds per run.

 

Congrats!

 

Well, as the only B stock car, my times were "PAXed" into A stock and I ended up 5th out of 6.

Results:
http://www.cumberlandmotorclub.com/R...renzy_fin_.htm


The good news is, my three runs without an OFF or DNF (oops) showed consistently improving times, and I am now certain that I could have done better with lower pressures. My outer tire wear is nowhere near the triangles mentioned above, and there are absolutely no scrub marks on the inner 3cm of tread. I can definitely use more of the tire than I was.

Thanks for the input!

 

Well - I will be putting my new Potenza s-03's on for the next event ... And I think I'll go a bit lower in pressure.

Thanx - Chris

 

Maybe I'm old school, but don't people still use show polish anymore? Or chalk?