911 Carrera RallyCross Project

4 minute(s) of a 245 minute read

It's time to start thinking about tires (and wheels) for autocrossing and track days for this thing. The car will be running in SCCA Street Touring class so DOT R compounds are out. Thats good as they wouldn't survive many track days anyway.

The hot tire in this class appears to be the Dunlop Direzza ZII Extreme Performance Summer



Suitable sizes available would be 205/55-16 front and 225/50-16 rear mounted on BRAID (of course) Fuchs replicas in 16x7, ET23 front and 16x8, ET10 rear. We all know this fits the Carrera body well.


But is this enough tire to be competitive?

How about Bridgestone's Potenza RE-11 in 225/50-16 front and 225/45-16 rear?




Perhaps not as grippy as the Dunlop but a lot wider. These could be fitted to the same wheels as the Dunlops though 8" front and 9" rear may be better but what offsets are needed to clear? Surley not the ET23 and ET 10 above? I know these tire sizes can be made to fit the Carrera body but I'm not sure what offsets work.

Any thoughts?

2-15-2013

Round two tomorrow. Currently lying first and second in Prepared Rear or, as it is now known "Porsche Rear". Wish us luck. Report, pics and videos next week.




Detroit Region SCCA: News

2-19-2013

I must say, this car is amazing. Considering it is basically stock it performs remarkably well. After all we are only in Prepared class due to our wheels being too far from stock spec ( 6.5" width) yet this thing just kicks arse. No understeer, loads of traction, plenty of power, narrow enough, short enough and fast enough. Incredible. It feels like cheating.

Detroit SCCA did another stellar job putting on the event based around a twin dirt oval in mid-Michigan. Needless to say we don't just go around the oval. See the video for a ride on course with my fellow driver Scott Harvey. (yes, he beat me)

Detroit Rallycross 84 Porsche 911 - YouTube


The challenge of this event was all about changing course conditions. With temperatures in the 20s all day were were greeted by frozen dirt for the most part. This had the consitency of sandpaper making for a very fast but twisty course. Except if the sun came out whereby the top 1/4" of surface would change almost instantly to liquid soap and prove a devil to drive on. This happened to me for my last two runs of the day resulting in them being a full 10 seconds slower than my previous runs. Never-the-less we came out in 1st and 2nd place again beating another couple of Porsches, these being 944s.




Some pictures at speed. It goes "all right" doesn't it?







There's supposed to be some helicopter-cam footage of the car too. Hopefully I can snag that soon.

It wasn't all roses though, there were a few casualties. This is what happens to a Porsche fog light when it hits a frozen solid traffic cone at 40mph:




and somehow my skinny tires on 35 offset wheels managed to contact the fender lip and bend it down. No big deal but what's going to happen when we lower it on 205s?



The new Corbeau seat and Momo steering wheel were excellent but we did have to remove the seat cushion to stop our helmets banging on the roof. Need to figure out how to lower it before the next outing.



Only rally guys would find eating lunch outside at 20F fun.






Next RallyCross is March 10th but we might get an opportunity to do some ice racing this weekend. Let's hope the weather cooperates.