Sabenza

Would fitting 04 'GT3 wheels with offset 40mm/63mm to 02 C2 Coupe lead to bumpsteer? Currently I am using 18" Carrera 5-spoke with offset of 50mm/65mm. I raises this issue with my local shop today and the mechanic says that there won't be any bumpsteer with the GT3 wheels. Is he right or is he just trying to sell me those wheels? Any comments is appreciated.

Steve in FL

As I understand it lowered cars are prone to bumpsteer due to changes in the steering rack geometry/alignment (on old 911s you installed spacers under the steering rack to compensate). Even with a different offset from the wheels you have now I expect the GT3 wheels will maintain the centerline of the wheel in relation to the hub so that would be minimal change in suspension geometry there.

Bill_C4S

Seem to recall that the GT3 front wheels are outsized for the C2 wheel well....the C2's front cowling impeding the full range of steering

Wheel Enhancement (no association) should be able to give you a definitive answer.

SPR

I have/had a set of bbs re's and with their offset even at 56 v. 52 it gave the car noticable bumpsteer. However when I fitted the pss9's those same rims wouldn't fit back up! needless to say Tom from Lucent is letting me borrow his rims 52mm sport designs and BTW there is no bumpsteer with those fronts- FYI to make the bbs re's fit with my pss9's it required 15mm spacers which screwed up the offset even more.

Basically you encounter bumpsteer when you change the centerline of the tire, i.e. offset. it's really a shame because I do like the look of the re's but they just do not work for me period. I am also a very sensitive driver, and I would expect most people wouldn't notice the problem as marked as I would. I am hopefully going to work out a deal with Wheel enhancement where I bought the re's and have been waiting for a call back for a week now, to see what we can do about this issue.

SPR

btw front gt3 rims are 40mm offset with an 8.5 rim. BBS re's are 8.5 with a 56mm offset and stock rims are 8" with 52 mm offset, dunno what the 7.5's are for offset or what the 17's are -

Sabenza

I thought the Carrera 5 spoke has 50mm offset at the front. This was show in Carnewal's website. Would your 56mm offset make the wheel go deeper towards the wheel hub versus the 40mm GT3 wheel offset which pushes the wheel towards the outside?

Has anybody try fitting these GT3 wheels on the C2 Coupe?

SPR

deeper in. I guess the 5 spokes are 50 whereas the sport design/gt3mk1 wheels are 52. I have seen the rims on a few other cars but I haven't driven them but was told there was no bumpsteer. I find this hard to believe given my problems with spacers giving me basically 40mm give 1mm of offset with those bbs'ers

Sabenza

I have my local shop installed the 04 GT3 Wheels yesterday and the shop agreed that I can test the wheels out for one week and if there is any problem, I can return the wheels. Meantime, I still keep my Carerra 5-spoke. Since I do not want to spend any money on new tires (235/295) yet, I reuse the tires on the Carrera 5-spoke which is PZero Corsa 225/285. I went for a casual drive after the installation and at this stage, there seems to be no problem with the wheels: the tires are not touching the fenders from lock to lock. I will go for a hard drive this weekend to see whether there is any bumpsteer.

The shop does not have any access to a bumpsteer measuring device. What does a bumpsteer feel like?

Sabenza

So far so good after a real hard drive on Sunday. No rubbing on fenders or bumpsteer yet.

01 C4 Cab NYC

Is there a chance that once you put on the 235/295 tires they might rub? You might want to check since the shop was nice enough to give you a week to try out the rims...