DigitalWidgets

I've just started autocrossing my 2011 GS. What a blast. I've searched for an exact answer to my question, but haven't been able to find it in the stickies or using the forum search:

Being new, I don't have any track day "accessories" like an air pump or tank, so for now, I'm just showing up and running what I brought. That being said, what should it set the tire pressures to before I leave the house? I read somewhere 5 over normal cold (not a Corvette specific recommendation), so I've been filling all 4 tires to 35psi, but to be honest, I have no idea if I'm in the right ballpark or not.

I've examined the tires after my two events (a total of about 35 runs), and the tires don't appear to be rolling over or have undue wear on the sides. I have yet to try some chalk or anything to confirm.

Anyway, I figured the CF brain trust would have some solid advice to help me out before I start throwing a lot of money into extra equipment for this endeavor.

Tinnit

35 is about right. I went to a Corvette club autocross school and several experienced racers recommended slightly higher in the front. Like 3-5 psi. Personally, I run 38 up front, 35 in the rear, but I don't have the runflats anymore, so YMMV.

As for not having the proper tools, go pick up one of these. It has everything you need for $50 and it's available at any Walmart. Amazon has 'em, too. I've been using the pump from the kit all season and it works well. The gauges you'll find in this kit and elsewhere in Walmart or any other local auto store leave a lot to be desired. At some point, you'll want to pick up a better gauge. I use a Longacre gauge. It's pricey for a gauge, but you'll be glad you did it.

also, how the hell are you getting 35 runs in two events? Most Solo events are 4 runs. The Corvette club event had a fraction of the cars and we still only got 9 runs in. I would love to get 17 runs a day...

DigitalWidgets

Thanks for the advice Tinnit. I'll push a little extra in the fronts and see how that feels this weekend.

I've only been to two events...the first was a Solo event at El Toro airbase (about a month ago) and I only got 4 runs (plus one extra with an instructor driving). I then found an event billed as a small Charity Practice type of thing. No work assignments (local college volunteers), no competition, no classes or run groups, just a course with cones and a clock. Just get in line and if you want to track your time, you had to write it down yourself. I started the day by logging every run into my iPhone. I was doing groups of 5 or 6 and then resting for a few mins. After 20 runs, I stopped logging my time, turned on the radio and just relaxed and enjoyed it. I found some consistency about 4 secs faster than I started the day.

It was great because I could work on some specific weak spots that the instructor identified in my competition event, and I also identified some new weak spots that I could use some instruction on for the next time I have an instructor in the car. I also got to ride with some Miata guys (and had a few ride with me) and learned some good stuff from them.

To be honest, at this point, I couldn't care less about the competition, I want to learn the car and practice. Kinda hard to do when you only have a few runs at an event.

Also, thanks for the hardware advice. I did see a few guys with air tanks and one with a little compressor that hooked to his battery like the Slime Power unit as well. My current air pressure gauge is a little $6 Walmart special. It gets the job done, but I don't know that it's all that accurate. But, without any source for air, it's kinda useless at the events at this point.

Tinnit

That sounds AWESOME! I would love to find something like that around here. I've even debated picking up some of my own cones and finding a large empty parking lot to practice slaloms, but I think the po-po would frown on that.

Heh. I said that my first half dozen events. After about the 5th or 6th one, I stopped trying to fool myself. The competition is way fun. I'm not even remotely competitive with the experienced folks, but I've discovered a nice crew of fellow novices and we're all real close time-wise. It's fun, friendly competition and I couldn't be more thrilled about those events.

I guarantee the $6 Walmart special is inaccurate. I'm pretty sure that Walmart QC would've pulled it off the shelf if it were remotely close to the right pressure. Here's the tire pressure gauge I have: Longacre 50413. It's accurate, easy to read, glow in the dark, and has a fast air-down button for tweaking the pressure. $50 on this and $50 on the pump from Walmart and you're all set.

I'm harping on this because tire pressure can make a big difference on the autocross course and it's one of the very few things you can tweak there at the event. Street tires have a sweet spot. They like to be mildly warm before they stick well, but they'll get real greasy if they get hot. One way to keep tabs on how hot they are is to watch the pressure rise. If you're letting out 1-2 psi per run, that's about normal. If you've had to drop 3-4 psi a few runs in a row, you can expect to see some loss of traction from overly hot tires. I've seen some of the more competitive guys running street tires spray down the tires with water. Plus, maintaining tire pressure gives you something to do between runs. I enjoy the routine. It calms my nerves.

DigitalWidgets

Oh, make no mistake, I'm very competitive and I'll be playing to win soon enough. I'm just very conscious of my inexperience and know darn well that I've got a lot to learn.

Quick story: In my family we're very competitive. We have a wonderful racing insult line: "There's a racing term for that...it's called losing!" The phrase surfaces on occasion, and whoever the target is, has to own it. Heck, I took my boys karting once for a birthday party and one of the kids in our group broke his foot in a crash. They red flagged the race for a bit, but my boys and I didn't get out of our karts to go help this poor kid...we were knee deep in the heat of battle (ok, we're not that cold, my wife did go help him)! Anyway, we find out he broke his foot the next day, and we went to talk to him. Sure enough, "Oh, you broke your foot dude? That's too bad. You know there's a racing term for that.....!"

Anyway, my very first autocross run was a big friggin deal to me (been a racing fan all my life, just never got around to doing it). It was a pretty big competition and there were some serious race cars in my run group. I signed up in the SS class with all the other Corvettes (didn't know there was a novice and street tire class). I figured I'd just roll with the big boys right out the gate. I grabbed an instructor and headed out. I missed one slalam cone, but as I screamed across the finish line, I thought to myself...hmmm...not bad for a rookie! Then I hear the announcer over the PA (with just a hint of sarcasm in his voice): "That was Randy Gonzalez in car 696 with a 95.286. That puts him comfortably in 12th place!"....out of 12 in my class...I have to admit, it did actually make me laugh for a moment. So I pull back in line and jump out of the car to talk to my whole family (that had come down to cheer me on). There's my 14yo son. "Hey Dad, did you hear the announcer! You know there's a racing term for that......!!!!" I deserved it, and I knew it!

My best time for the day, didn't beat anybody else in my class worst time. But that's OK, I looked at the novice times, and I wasn't a complete disaster. Either way, I had a blast and am determined to learn what I can and at least get in the game.