Autocross Lessons Learned

**phredden** · #1 (**permalink**) 07-18-2008, 11:02 PM

I now have a couple of events under my belt with the car prepared for SCCA AS, and/or COM Stock, and/or PCA "Production" class. I fitted an exhaust(FabSpeed), Bilstein (non adjustable) sport shocks, and tires. Being a creature of habit, and cheap by nature (

) I went with Kuhmo 710s, 245/285 on 18" TireRack aftermarket (read: cost effective) rims in stock "S" size. Other than that, bone stock...no desnorking, no chip, etc. (According to my math, this cost about 1/2 what Hoosiers on factory rims would have cost...)

Verses a 911 or BMW 3-series, which have dominated my car collection for the past 25 yrs, this is a unique creature. This whole mid engine thing just might catch on! It's taken me a while to really fully comprehend the grip and balance to a fraction of it's full potential. Last season I ran it in "strictly stock" at PCA events and had a lot of fun dicing it up with some fast Boxsters. I won two events, came second in two events, both to the same guy. But once I fitted the r compounds the car really came alive.

Here's what I've learned over the past month, so hopefully this will make it easier for others in their learning curve....

1. go much faster than you think you can in slaloms....the car has almost unlimited ability to do slaloms, about as fast as your eyes can focus, MUCH faster than a 911 or front engine car.

2. go with very low pressure if you're running 710s, I mean 25 lbs max...which is around 3-4 lbs lower than we thought just last week. My codriver (the brains of the operation) dropped them during his PM runs and handed over the car to me and it was absolutely a different car, and I took nearly 2 seconds off my time.

3. experiment with pressures front/rear. being an old 911 guy I naturally migrated toward the 2+ in the back...not so much with these cars. we had great results with dead even, or even 1-2 + in the front.

Other than that it was back to basics: don't be afraid to use the brakes...remember, when in doubt slow in fast out; look and keep ahead, always do most of your turning BEFORE you get to the gate, not at the gate, or even worse, after the gate; don't be afraid to spin...it's like falling skiing, if you're not doing it at least once a day you're not trying hard enough; charge those slaloms HARD, remember to turn when your first headlamp crosses the line between the cones, nearly everyone turns too late.

Net result is that in a field of 60 we put this little 2.7 only 0.5 seconds off FTD all classes combined, just getting nipped by a modified GT3 RS, and a 2200 lb 375 hp all out carbon-bodied 911 race car, both on race rubber. These cars can do it, guys. I hope these hints will help....

jmazz · #2 (**permalink**) 07-19-2008, 01:54 PM

Thanks for the tips. I've done a few autocrosses this year and would like to get a lot more serious about it next year. Getting more serious of course means getting some better rubber. That's one downside with the Cayman. There's no way to transport your race rims without another vehicle. Are there any good tires that I could drive to an event?

I'm curious, but wouldn't your exhaust take you out of the stock class since you removed most of the cat?

FT · #3 (**permalink**) 07-19-2008, 09:21 PM

Quote:

Originally Posted by jmazz

Thanks for the tips. I've done a few autocrosses this year and would like to get a lot more serious about it next year. Getting more serious of course means getting some better rubber. That's one downside with the Cayman. There's no way to transport your race rims without another vehicle. Are there any good tires that I could drive to an event?

I'm curious, but wouldn't your exhaust take you out of the stock class since you removed most of the cat?

I haven't kept up with autox tires lately, but you may want to consider the STU class if the car qualifies, which I am not sure that it does. Otherwise, may want to try R888 tires, shaved, which you can drive on the street with. Depending on what you mean by 'getting serious,' you may have to buy one of those small tire haulers and have hitch mounted on the car. My opinion is that I would not get too serious with the CS in autox, I don't think it can really do much against its competition in the class it is now. May be if it is moved into SCCA's AS class, but otherwise not worth spending any money on the car to be competitive.

http://www.moutons.org/sccasolo/Lists/2006/stockc.html

For PCA autoxing, in stock form it performs the best and I don't think any other P-car can touch it, so no need to spend any money, except putting some Falken Azenis or Bridgestone 050s.

**phredden** · #4 (**permalink**) 07-20-2008, 06:44 AM

Quote:

Originally Posted by FT

I haven't kept up with autox tires lately, but you may want to consider the STU class if the car qualifies, which I am not sure that it does. Otherwise, may want to try R888 tires, shaved, which you can drive on the street with. Depending on what you mean by 'getting serious,' you may have to buy one of those small tire haulers and have hitch mounted on the car. My opinion is that I would not get too serious with the CS in autox, I don't think it can really do much against its competition in the class it is now. May be if it is moved into SCCA's AS class, but otherwise not worth spending any money on the car to be competitive.

http://www.moutons.org/sccasolo/Lists/2006/stockc.html

For PCA autoxing, in stock form it performs the best and I don't think any other P-car can touch it, so no need to spend any money, except putting some Falken Azenis or Bridgestone 050s.

Yup, those (Azenis and 050's) would be what the tire geeks are recommending this season for non-R compound sneaks, and perfectly capable of driving to and from events. If you hit a downpour on the drive home, and they're shaved, things get pretty exciting, thou. There's definately a lot to be said for staying absolutely stock. But, in my area right now the best competition happens to be in the PCA "Production" class, by far. Also, in the local time trials there are no classes which ban r compounds, so, if you want to be even remotely competitive you have to go there, even in the most stock classes.

Regarding exhausts, my understanding is that PCA production classes list exhausts as "free". My exhaust retains two cats and easily passes emissions, so I can't imagine there'd be an issue. As far as I know this is also the case with SCCA, and certainly is with COM, the TT sponsors.

Not sure which variant "jmazz" is running, but my 2.7 seems pretty much in the game with SCCA, and yes, I think the S will struggle where they put it as there's not really a huge difference in the two on an autocross circuit. To that I'd say seek out the PCA events. We had around 16 Boxsters and Caymans last weekend and some great, close battles. Our local chapters just lump the S's and normals together and it's still the driver who determines the outcome. I find it a lot of fun to run against a "one design" field, where everyone has pretty much the same hardware....rather than agonzing and speculating whether or not it was the man or the machine that determined the outcome.

**Fort Felker** · #5 (**permalink**) 07-20-2008, 07:24 AM

Quote:

Originally Posted by jmazz

There's no way to transport your race rims without another vehicle.

Not true! See Roof rack tire transport - My Articles.

jmazz · #6 (**permalink**) 07-20-2008, 03:44 PM

Thanks for all the replies guys. Sorry to hijack the thread.

That roof rack scares me a little. I wonder if you slanted it forward if you could get any downforce.

I've got a 2.7 and would be mostly running SCCA AS. I don't necessarily want to be competitive, I just feel like with good tires I'd get a lot more out of the car. Of course being competitive does make it more fun. Looking at those tires I would consider getting some R888s. If there is rain in the forecast I could just leave the PS2s on.

NoCones · #7 (**permalink**) 07-20-2008, 08:36 PM

Quote:

Originally Posted by phredden

Regarding exhausts, my understanding is that PCA production classes list exhausts as "free". My exhaust retains two cats and easily passes emissions, so I can't imagine there'd be an issue. As far as I know this is also the case with SCCA, and certainly is with COM, the TT sponsors.

From SCCA rules (13.10.A):
"Modifications of any type, including additions to or removal of,
the catalytic converters, thermal reactors, or any other pollution
control devices in the exhaust system are not allowed and the
system must be operable. Replacement catalytic converters must
be OE."
None of the cats can be messed with, even if you still have others that are operable and/or you can still pass emissions.

I think someone has asked the SCCA for some clarification on exactly what you can legally do with system such as the Cayman's.

**roadmaster** · #8 (**permalink**) 07-20-2008, 10:02 PM

Nice and helpful comments, phredden. I'm curious as to if you run with PSM on or off ?

**phredden** · #9 (**permalink**) 07-21-2008, 03:13 AM

Okay, thanks NoCones, I guess I've been told! If anyone challenged me I'd point out that the car has two (100% OEM) cats, they perform their function perfectly, and the car passes our state's rigorous emissions easily.

But you know what, it's all pretty academic because frankly I don't have the patience to sit around all day, at least the way it is in our area, at an SCCA event for 3 runs/day, when I can go to a PCA or BMWCCA event and get 8. The later PAX non-BMWs on the SCCA system and certainly don't go around counting cats...if the car has cats and passes emissions it's cool. And at PCA events the system is 100% legal hands down in production classes.

Regarding PSM, I assume that's the PCar traction control system? Oh yeah, definitely off autocrossing. I typically recommend students keep it on at the track for their first couple of days, and monitor how often the light flashes on. If it's lighting up like a Christmas tree all the time, might want to do a few more days with it on. If it only comes on from time to time, the brave may want to start experimenting with it off at the track. But autocrossing? No way, off from day one. This is THE place to spin. Get it out of your system now. It gets a LOT more expensive after this!

Finally, Jamazz...please note that the R888s, great tires as they may be, are "r" compounds and will knock you out of the "strictly stock" class in PCA. You'll suddenly be in "Production" where folks will have lots of suspension mods that could be discouraging to compete against. And, while I love the RA1/R888 tire as a durable track tire, it's not a great autocross tire by any means...it takes too long to heat up vs. a Kuhmo 710 or Hoosier A series. If you want to go with a Falken Azenis or similar you could skip the roof rack/trailer route and just drive to and from events no problem, and stay in strictly stock. If it's a long drive to events, just go easy on the shaving.