Recommendation for Autocross Tires & Wheels

[bkw5150]

I have a 991 C2 Cab and am looking to start AXing regularly. I am a novice, but serious about getting better. I am looking for a recommendation for tires and wheels from folks with much more experience than me. Any help would be greatly.appreciated.

[marcus981]

Hi Keith,

I'm sure others will chime in that have more experience than me, but I'm replying since I went through a very similar experience one year ago for my 981 Cayman S. Here's what I learned after doing 6 track weekends and 15 AX's with PCA-SDR/OCR/LVR and SCCA in the past year.

I did a lot of research on wheel/tire options and combinations for the 981, since the stagger and different rolling diameters makes the selection more tricky for us compared to most other cars. Here's a link to a spreadsheet (PDF) that I put together, primarily for tire options. It won't directly apply to your car, because of your wider rear wheels/tires, but it should still help.
https://www.dropbox.com/s/s13pypi0959hv2z/981_Wheels_Tires_Research_2014_10_19.pdf?dl=0
Out of those tires, I've used the Bridgestone RE-11, Hankook R-S3, and currently the Dunlop Direzza ZII-SS, all of which are popular choices for AX's. I had good luck with all of them, but the R-S3 shoulders started to wear very quickly until I modified my car to get more negative camber than stock, and then they were great. The RE-11's are known for stiffer sidewalls, so they didn't have that issue, and I believe the Direzza's fall somewhere in-between.

Wheels seem to be the more subjective of the two topics, and there are many options to chose from.
The OZ wheels from TireRack.com are a popular choice that you'll see on several cars at our events, and that's what I selected for my dedicated AX/DE/TT set. I went with an 18" set (while stock is 19" or 20") to give me more options for tires, and so the tires would be less expensive. It also gives you some flexibility in a lower ride-height, if desired. I believe the 18" wheels should also fit on your 991, since I think your front brakes are the same as mine, so 18" wheels will clear the calipers. I'm not sure about other 991 models though, since I believe some higher HP models use larger brakes. You'll want to pay particular attention to the wheel offset. My spreadsheet has some info on that, but a Tire Rack rep can also help make sure you're selecting the right offset, especially if you want to try to get wider wheels/tires than stock.

For tires, you'll probably want to focus on the "Extreme Performance Summer" category from Tire Rack. That will ensure that you're getting a good trade-off for dry grip and tire durability for AX or track use, while sacrificing some cold and wet weather traction. I started chunking my stock Pirelli tires after only 2 AX events, so stepping up one category to one of those "Extreme Performance Summer" tires made a night-and-day difference in my tire wear. There seems to be some folks that run AX's on their stock tires without problems, but I also know of several others that had similar experiences to mine.

I hope this helps get you started. See you at one of our AX events!
Marcus

[ttweed]

... started to wear very quickly until I modified my car to get more negative camber than stock, and then they were great.
... I started chunking my stock Pirelli tires after only 2 AX events...

Marcus has given you some great advice, Keith, but I would emphasize this element above. If you are going to start AXing regularly, do your car a favor and get a 4-wheel performance alignment. You might be able to get away with an event or two on the factory alignment when you are beginning and not pushing too hard, but once you start cornering and transitioning at the limit, you could see some abnormal wear pretty quickly with a factory alignment (which has some pretty wide parameters and is optimized for safety rather than best handling balance). Just the normal accelerated tire wear is bad enough on the wallet, as you will find out.

Have fun,
TT

[Kim Crosser]

... you could see some abnormal wear pretty quickly with a factory alignment (which has some pretty wide parameters and is optimized for safety rather than best handling balance).

Amen... My Boxster had positive camber on one front wheel from the factory - talk about outside tire wear...
Talk with others about your particular model and how they set up their suspension, but you probably want to increase your negative camber and usually minimize toe-in (I have zero toe-in on my front wheels). Factory setups have wide allowable parameters, and usually have quite a bit of toe-in to make the car track smoothly over freeway concrete grooving.
New tires will help, but a "performance alignment" will make them work even better.

[surferr]

Really nice of you Marcus. A lot of knowledge for 1 year of tracking.

Hi Keith,

I'm sure others will chime in that have more experience than me, but I'm replying since I went through a very similar experience one year ago for my 981 Cayman S. Here's what I learned after doing 6 track weekends and 15 AX's with PCA-SDR/OCR/LVR and SCCA in the past year.

I did a lot of research on wheel/tire options and combinations for the 981, since the stagger and different rolling diameters makes the selection more tricky for us compared to most other cars. Here's a link to a spreadsheet (PDF) that I put together, primarily for tire options. It won't directly apply to your car, because of your wider rear wheels/tires, but it should still help.
https://www.dropbox.com/s/s13pypi0959hv2z/981_Wheels_Tires_Research_2014_10_19.pdf?dl=0
Out of those tires, I've used the Bridgestone RE-11, Hankook R-S3, and currently the Dunlop Direzza ZII-SS, all of which are popular choices for AX's. I had good luck with all of them, but the R-S3 shoulders started to wear very quickly until I modified my car to get more negative camber than stock, and then they were great. The RE-11's are known for stiffer sidewalls, so they didn't have that issue, and I believe the Direzza's fall somewhere in-between.

Wheels seem to be the more subjective of the two topics, and there are many options to chose from.
The OZ wheels from TireRack.com are a popular choice that you'll see on several cars at our events, and that's what I selected for my dedicated AX/DE/TT set. I went with an 18" set (while stock is 19" or 20") to give me more options for tires, and so the tires would be less expensive. It also gives you some flexibility in a lower ride-height, if desired. I believe the 18" wheels should also fit on your 991, since I think your front brakes are the same as mine, so 18" wheels will clear the calipers. I'm not sure about other 991 models though, since I believe some higher HP models use larger brakes. You'll want to pay particular attention to the wheel offset. My spreadsheet has some info on that, but a Tire Rack rep can also help make sure you're selecting the right offset, especially if you want to try to get wider wheels/tires than stock.

For tires, you'll probably want to focus on the "Extreme Performance Summer" category from Tire Rack. That will ensure that you're getting a good trade-off for dry grip and tire durability for AX or track use, while sacrificing some cold and wet weather traction. I started chunking my stock Pirelli tires after only 2 AX events, so stepping up one category to one of those "Extreme Performance Summer" tires made a night-and-day difference in my tire wear. There seems to be some folks that run AX's on their stock tires without problems, but I also know of several others that had similar experiences to mine.

I hope this helps get you started. See you at one of our AX events!
Marcus