C4TT

Any wheel experts (Adrian) know if this will work on the C4?
Thanks!

Greg

Fronts:
18 x 7.5 (50mm offset)
Part No. 993 362 134 06
Michelin Pilot Sport 225/40 ZR18

Rears:
18 x 9 (52mm offset)
Part No. 993 362 138 01
Michelin Pilot Sport 265/35 ZR 18

Computamedic

Greg,

These are the Boxster/996 Turbo look (Cup 3) wheels. I had the fronts on my car although since I've got turbo arches there was a 26mm spacer fitted as well. If you fit them without any spacer I would check for contact with the chassis towards the rear of the wheel when on full lock. You might find that some size of spacer is required to eliminate contact.

I think the rears are fine.

There will be plenty of people telling you that 18" wheels are not approved for the 964. They will be absolutely right - but it doesn't seem to have stopped a load of people fitting them. Just take a look at Christer - loads of work done by Colin Belton at 9m - and that's got 18" wheels. I'm sure Colin would have said something if he was unhappy about it.

I think the Cup 3 wheels look really good on a C4. Because of my turbo arches I've now got 8.5 and 10s on mine (Mille Miglia wheels) with 16mm and 30mm spacers.

Hope you like them.

Best regards



Dave

asbi

Your main issue is going to be with the offside rear wheel where there is a metal pipe that runs across the back of the wheel to the oil tank.

If your car has the original pipe then you will almost certainly get a rubbing problem with larger than std wheels. When Porsche went to 17" CUPS as an option (1992 MY I think?) they changed the design of the pipe to follow the body contour more closely and also introduced a flat on the pipe at the point it crosses behind the wheel rim. You can either replace the pipe or remove it and carefully flatten out a section and bend it to fit the inner wheelarch profile more closely.

In my case I got my specialist to gently tweak the existing pipe, this removed the rub issue I had (17 x 9" Mille Miglia CUPS et47mm), obviously this should be done carefully since if the flat is too extreme you could end up restricting the oil flow-my specialist used the newer pipe as a "pattern"
Cheers,

Bill Gregory

In 1992, when Porsche went to 17" rims, they added thicker steering stops (6mm=>10mm), so, that's one update that should be done, if not already. Generally, when fitting larger rims in the rear, you need to watch for rubbing several places: on the body at the 12 to 3 o'clock position on the drivers side and 9 to 12 position on the passenger side, the swing arms, and the passenger side oil line.

joey bagadonuts

These should fit. While the rim diameter is an inch bigger, the tire is virtually the same size due to the shorter sidewalls. Based on the specs, their overall diameters are 25.09" f and 25.30" r but the rear tread width is approaching the limit. While it's only an additional 10mm (0.4") over a 255, there isn't a lot of wiggle room in those rear arches.

If your car's suspension is in good shape, you shouldn't have a problem. The offsets are the key specs. With stock being 52.3mm f/r for a 964, the 50mm f and 52mm r will work just fine.

C4TT

Awesome guys! Thanks so much!