will C2S wheels fit C4S

[pdavis1]

Will the Sport Design wheels from a 2006 Carrera 2 S fit a similar year Carrera 4 S?

[Loren]

Yes and No, the offsets on the rear wheels are different.

C2S Sport Design Wheels:

Front: 8 J x 19 H2, RO 57

Rear: 11 J x 19 H2, RO 67

C4S Sport Design Wheels:

Front: 8 J x 19 H2, RO 57

Rear: 11 J x 19 H2, RO 51

[pdavis1]

Does that mean that the rears would fit with 16mm spacers?

[Mijostyn]

The rears have less offset so the C4S wheel will stick out 16 mm further. We all need to get this spacer issue straight. You can not just stick any old spacer you want on these cars. The limiting factor is the length of the wheel centering flanges on the hubs. Wheels ARE NOT LOCATED BY THE LUG BOLTS. They are indexed to the hub by the hub flanges through the wheel's center hole.

Here you have a C4S front hub with the Porsche supplied 5mm spacer. The hub flanges also center the disc and the spacer. What you see left is 7mm of flange sticking out. I already have to be very careful taking my wheels off. If I do not hold the wheel tight against the disc when I remove the last bolt the wheel comes crashing down on the brake caliper.

Here is a shot through a mounted wheel with the center cap off. See the flange?? It is holding on to the wheel by a mere 5 mm! If you put a 1 cm spacer on the car the flange would be holding on to AIR==NOTHING==NADA!!! It is now IMPOSSIBLE to center the wheel. This will result in a CRAP ride, SCALLOPED tires, DESTROYED wheel bearings and god knows what else.

Unless you know someone who makes custom wheel hubs for these cars with longer flanges, DO NOT use anything more than Porsche's 5mm spacers and even these are a pain in the neck (experience talking). There are spacers that have a centering ring to index the wheel by its center hole. These spacers fit over the hub flanges and are centered by them but I still do not like them as they compound errors, the ring is machined out of the aluminum spacer which means the spacer itself has to be thicker to support the centering ring and you can not make a spacer this way at all that is thinner than the hub flanges are tall. Spacers between 5mm and 1.5 cm are pretty much out of the question. All this stuff also adds unsprung weight. You can get 17 and 21 mm spacers from Suncoast Parts that have centering rings. Best is just to stick with wheels that have a 51 mm or slightly less offset.

Edited August 6, 2013 by Mijostyn