I have my first autocross event coming up this next weekend. I have the requisite helmet and some stick-on numbers. I am working on getting my hands on an air tank for purposes of playing with tire pressure.

From A to Z, any advice would be appreciated...gear selection, tire pressures. etc. I'll be driving my '07 z51.

Thanks.

 

Check out the Autocrossing and Road Racing section of the forum: http://forums.corvetteforum.com/forumdisplay.php?f=23

Better answers - it's where the racers live

 

Ride with some of the experienced drivers then let them ride with you. Ask questions and listen. Smooth is fast.

 

I found that the GY tires on the Z51 were not that responsive to tire pressure changes. I was running around 35psi front & 30 psi rear.

If you decide to use this as a starting point, check the scrubbiing or scuffing pattern on the tread after a run. This'll give you a general idea as to how much of the usable tread you're using based on tire pressure.
You'll probably find that you got what you've got because of the tire not responding to pressure changes.

That being said, the GY tires on the Z51 were not all that bad IMO (I'm currently running the PS2's, which I like a bit better).

As far as the drive, initially, just 'drive thru' the course. Don't worry too much about late apexes, trail braking, etc. You'll get into this more
later on. That being said, the most important thing I'd try to do is make sure that you look ahead at least 2 gates. This will make sure
you don't get suprised by the turn -- things will be happening really quick.

I still end up telling mentally myself to look ahead during a run.

Finally, make sure that you HAVE FUN!

 

Emphasis on bold part.

Your first time out I would not worry much about the car itself. Put in about 34#s front and rear and just worry about your driving.

In order to be smooth, one lesson I learned was to get it into second gear and leave it there. Very few courses require third gear. The problem with going back down to first gear until you get more experience is that you are going to get way more acceleration than you are likely able to put to the ground without spinning the car. Even if second gear feels too high, you will be much smoother and be able to get back on the gas a little earlier with less risk of spinning.

I would make all runs in the competitive mode.

 

With the stock GY Supercar EMTs, I found the street pressure of 29 psi cold front and rear worked very well. Pumping the tires up to a higher pressure will reduce your grip.

 

I tried 37psi front and 32 psi rear based on a recommendation from this forum and the car was almost undriveable due to understeer. I lowered the fronts down to 32 and it was much better.

 

I concur with both of these posts. I ran the GY runflats a full season last year. My datalogger which captured G-forces said that once the runflats get above 36 psi on the front the grip falls off a cliff and almost gets as bad as a wet track.

Street pressures of 30psi are a fine starting point.

 

Thanks for all the posts. I would add that I have BFG KDWs (non runflats)- any additional thoughts on tire pressures?

[Two of my GYs bubbled in the sidewall in the first 5k miles (despite the fact that Ive never so much as hit a speedbump hard in the car) and GY would not replace them. Claimed that the treadwear was too significnat to warrant them with such low mileage. No more GYs for me EVER.]

 

I ran an autocross recently on the KDW's. I only autocross once every few years, so (as my advice above said) I don't spend a whole lot of time prepping the car. I know the car is better than I am. I ran 34 all around. The rear end will try to get away from you - trust me. Just drive smoothly. I might be inclined to drop them to 32, but I really don't think that should be a huge concern.

BTW, out of around 30 total Corvettes, I finished second overall (as I have the past four times I've autocrossed in the past seven years).

 

It helps to have someone experienced at autocross ride with you the first few times.

 

I agree. 30 psi and concentrate on learning the track and being SMOOTH!!!!

PS take your wife along for some good fun!!!

 

Silver is the fastest color for autocross. My wife has also ridden along and she really surprised me on how much she enjoyed it!

 

I just autocrossed this last weekend... Here is the drill:

1- Empty your car of EVERYTHING. That includes the floormats. I run without the top; it is unecessary weight where it hurts the most; up high.

2- I started out with 40PSI all around and worked down from there. Found 36PSI front 34psi rear to work well on my Michelin PS2s

3- Tried competition mode, but it didn't work as well on that particular track.... I had the same experience with the Z06. I found that I could generate plenty of wheelspin with traction control and a/h on and my times went down, so I just ran with them both on; this is specially true if you don't know the car well.

4- Take it easy; if you are sliding around you are being slow. I learned a lot by riding with pro drivers and having pro drivers ride with me... I'm still not good, but I get a little better every time; you will too.

Most importantly: HAVE FUN!!! Every place I go there is always that one douchebag who shows up trailering his car and 2 extra sets of race rubber and spends the day running around his car after every single lap, checking tire thread temperature at different spots on each tire, watering the tires to keep temps down, monitoring and adjusting the pressure, icing his intercooler, refusing to answer any questions about his setup or talk to anyone... I refuse to believe these people are actually having any fun.. I'd much rather show up on my daily driver, burn some rubber, learn where the limits of the car are, learn how it behaves at the limit and how to handle it once those limits are exceeded...

 

Best advice is get all the crap out of your car.
Start at 32 with the KDW's and adjust from there based on scrub marks on the edge of tire, there are little arrows there to show you how much of the tire you should be using.
I would run with the TC and active handling completely off.
If you have it on and you are fast, it will prevent you from doing the things that make you fast. If you have it on and you are slow it inhibits the learning curve of controlling the car yourself and learning to go fast.

Oh yeah, have fun, you will love it.
Definitely check out the autox roadracing section on the forum, lots o track heads over there.

Are you coming out to the Lone Star corvette classic autoX on friday at the TMS bus lot?
if not hurry up and get signed up and get as much seat time as you can.

 

Great advice... probably the very best "first step" you could take! Have fun!

 

I wont be able to make it Friday, but am headed to the SCCA event in Mineral Wells on Sunday. Thanks for the advice.

 

Oh yeah- one last set of questions:

- should I take a novice designation or not?
- I dont have any mods that should bump me up (only Flowmaster mufflers and a basic cold-air intake), so what class do I run- is it super stock (ss)?

Thanks again.

 

I'd take the novice designation if I were you. It doesn't change anything though.

I believe only the Z06 is SS; C6 is AS.

 

Both the Z06 and the C6 are in SS. Doesn't seem fair, but unless it's a wide open course the Z06 only has a slight advantage.