ttreat

Well, I was able to get to my first autocross with my '01 996 C2. I have had the car since January and my comparisons are to my previous autocross car, a 91 MR2 Turbo. I must say on the street the 996 feels so much more stable. I was concerned that would translate to a much less nimble feel while autocrossing. Wow, was I wrong. The 996 is every bit as or more nimble. Unfortunately, I have Conti SportContact 2s on the 996 and I was using Hoosier R6s on the MR2 so I think I left a lot of time out there due to grip.

I have a few questions and would appreciate some advice.

1. The front end feels very light on the 996. Is that mainly due to not having R compound tires or is it due to my comparison of a mid engine versus rear engine car?

2. What are some techniques that I could use to get better grip from the front end (setup, weight transfer, etc.)?

3. Are there more competitive non R compound autocross tires? How many people use R compound tires for autocrossing? Does anyone take heed to the owners manual about not using R compound tires?

Also, I was using around 38 psi up front and 40 psi in the rear. That seemed to get about the best sidewall rollover.

Thanks.

Scootin159

Nothing 996 specific, but I used Toyo RA1's for a while autocrossing. They're not as quick as Hoosier's, bit still much better than any street tire. They will also last MUCH longer than Hoosiers, and can even be used for track days.

Heidster

I autocrossed a 911SC for ~ 13+ years that was fairly modified with R compound tires and suspension mods. I could run ~95%+ of FTD. Now I have a stock '99 996 with no LSD. I was a bit worried that I'd have to go modding again (even before I autocrossed it) to have fun. I was surprised that I had fun @ even ~90% of FTD. (Old P-0's dont help.) The extra low end power and ABS was new to me.

Low speed understeer is usually the issue in stock form for these cars. I think the least expensive/intrusive thing would be more neg camber in the front to reduce the low speed understeer. Tire pressures as you mentioned would be seem to be in a good range. As always you have to adjust driving style on the fly to compensate.

Any mods (adj. sways, R-1's etc) would put you into a prepared or improved class.

Having fun without spending $3-5K for the extra 5%, is more my style now.

MechanicalEng

I AXd an 02 996 C2 for 3 years and as Heidster said you need to add as much camber as you can up front (push the struts all the way in), get R-compounds and run the widest tire you can up front and leave the rears the same size..

utkinpol

Suspension issues do not have such a critical impact on auto-x as on a track, so, if you ever going to run car on DEs - some work there is worth doing. Stock max front camber is about of -1.1 degrees, having that with 0 toe and -1.5 degrees rear with 0.10 toe helps, but it is not nearly same feel as with GT3 front LCAs that give up to -3 degrees camber, GT3 rear swaybar to cut down understeer, and tarett rear toe links to be able to get max negative camber in rear axle while keeping toe at 0.10.

I never understood why Porsche is not using same GT3 LCAs and upper mounts on all models they make, it is just odd. They do fit and make a heck of a difference. Going from -1 degree camber to -2 degrees also makes a heck of a difference. All of that cumulative totally transforms your car to its full potential.

springgeyser

#2 Get some
-GT3 ARB.
-you can slot the front tower to get more negative camber.
-wider front tires reduces the understeer greatly.

ttreat

Thanks for the advice on mods but I do want to keep the car stock. I can use different rubber and have the camber adjusted to its max limits but I slotting the strut mounts would put me out of A stock. I also could install a larger front sway bar if that would help (I am surprised that nobody mentioned this). The problem with mods is that you can't just do a few. If you do one that puts you into another class you need to put a lot of money into it to be competetive.

Nobody commented on other tires aside from R compounds. Has anyone used any other tires other than R compounds that give relatively good grip without going to R compounds? Something comparable to what many use in the ST classes.

porrsha

Horse pucky sir. The correct caster, toe in, etc means a ton.

If you slot the front tower go immediately to a nasty class like Street Prepared or Prepared.

Great response as you clearly have an end class in mind versus adding something and finding out after the fact that you are in modified all of a sudden.
Tires...R compound tires in stock class are a must have unless the club you are running with has a stock stire class, usually with wear index of 140+. Zone 1 PCA has a stock tire class. The Zone 1 site may have some rules you need to follow. I always ran R hoosiers for years..now running in ST-R so it has a spec tire.

ttreat

I used R compounds on my MR2 and they felt great. But, it was a pain to switch tires when I got to each event. I also could fit the four wheels in the MR2. I don't know if I could fit the extra wheels in the 996 nor do I really want to. I can have a lot of fun with the car as it is but I think I would like a little more stick with the front. I used to run a car in STS with Falken Azenis tires and I think that type of tire would be a good compromise. My local region really doesn't have a huge turnout and the larger classes are SM, SSM, and ST. I was the only one in AS at the last event so it is more about having fun and learning how to drive this car than beating others in my class.

00r101

I recommend driving the car on street tires for a little while longer. Although you are an experienced autocrosser and could go to R tires at any time, I believe you will learn more about how to make the car do what you want on street tires. Getting the fornt end to turn in is about driving technique. Get more weight on the front end by trail braking into corners or by a quick lift at the right time. The street tires will give you a lot more aural feedback than the Rs so you can more quickly adjust your technique to what works best for the car. Then you can carry over that hard won knowledge to R tires.

My first year with the Boxster was spent on street tires even though I have autocrossed on R tires for over ten years.

ttreat

Can anyone answer my question about the best option for non R compound tires? The car has 265/35-18s on the back and 225/40-18s on the front.

edfishjr

I decided on Yoko Advan 08's for my rather heavy CTS-V that I autocross. Other popular auto-x tires in 18" sizes are the Bridgestone Re-11, the Kumho Ecsta and the Dunlop Direzza Stars. These are the 4 in general use at this moment. For me it was between the stones and the yokos. The yokos had a perfect size for me that would max out available space in the front.

00r101

Dunlop Direzza Sport Z1 Star Spec
265 - $236 each
225 - $175 each
At Tirerack.com

They are a little on the noisy side, useless in the snow, have tons of grip in the dry and pretty good in the rain.

I recommend going wider in the front than 225 (235 or 245 should work on your OEM size front rims) to reduce understeer.

MechanicalEng

put 245s on the front

utkinpol

As of sway bars you do not need to have stiffer front - for reducing understeer you need stiffer rear sway bar and you can get GT3 one for that - it has 3 adjustment points and is very easy to put on. get tarett droplinks for it too. front sway bar is not easy to put on.

as for tires - PS2 are pricey but are quite good. IMHO they are still the best.
RE-11 are good. There are other tires and reviews online

http://www.racingtireguide.com/autoc...eet-tires.html