Hi guys - I figured instead of experimenting, I'd ask...

I picked up a set of 18x8 and 18x9.5 BBS Motorsport wheels for my C2. Offset as I understand the wheel is 52mm. With a 9.5 rear compared with the 10" rear I had with the MY02s, I think I'm about 10mm off right now (inboard). 52mm + 6.5mm (1/2 of the 1/2" differential) = 58.5mm net "how it sits" compared with the 65mm MY02. I needed an 18mm adapter to make the MY02 sit perfectly at a net 48mm. To get the BBS there, I'd need a 10mm spacer. Sound right?

1/4" spacers are readily available and very inexpensive ($25 a pair), but... I found a source at $80 a pair for 10mm - anyone have any other options?

Thanks!

 

Full disclosure, I don't own one of these
but
the info I have says that the guys w/ 9.5 ET 68s use 21mm spacers for a net o/s for the 9.5 of 47mm

flatened oil line and rolled lips

subtract the width of the spacer from the native wheel ET to find the effective ET

let us know what you do, I can add it to my wheel page

 

Will do Bill. Right now at et 52 9.5" and a 265 rear, I've got minimal clearance to the oil line. I could run the car this way. But I've got about 20% of the available clearance to the inside of the car vs. 80% to the fender (without rolling). Trying to get it right in the middle and I think my math / observation is correct at 10mm... Also, BBS RS-GT in 9.5 built for the 964 comes with an et of 48...

 

An ET of around 47 is right for the 9.5J/10J wheel. I don't know if your BBS wheels are anything like my LMs but I had a big problem with mine and spacers. The LMs have hardly any space behind the wheel for protruding studs (assuming you are using spacers with integral studs). I initially had 18mm spacers on the front (it's a wide body conversion) and the studs on the hubs protruded too far to allow the wheel to sit on the mount - they just balanced on the top of the studs. I had to fit 26mm spacers in order to reduce the length of the protruding studs for the wheel to fit.

I already had big spacers (32mm) on the rear but you may have a similar problem if you try fitting 10mm spacers.

Regards

Dave

 

Dave, move your front suspension to the outboard position and you can remove your front spacer. That is how all 964 widebody suspension is mounted.

 

Geoffrey,

It's not that I didn't consider it, but remember that it's a C4. That means that the drive shafts would have to be changed as well as the sway bar - and I wasn't prepared to swallow those costs.

Regards

Dave

 

Ron, 10mm is too much for ET of 52mm. It will give you 42mm. I have 45.5mm offset with a 9.5 wheel and guys running 10s have a 44mm offset with a few degrees of negative camber. Like Dave mentioned, I don't think your BBS wheels will allow spacer with studs cause I doubt the hart of the wheel is cut to let the nut pass through. The only time the original nut don't get in the way is way you use a 30mm spacer.

I would opt for a 3mm shim to get your offset to 49mm and leave it like that. Anything bigger than 6mm, you'll have to get longer studs.

Good luck

 

My shop has the car now and says 1/4 will help and that 10mm may be perfect. Longer studs will be needed regardless. The wheel stickers say et 52, but I'm not sure I believe it because of how inboard they sit compared with the OEM Cup 1s and the MY02s with 18mm spacers (net 48). Then again, offset all depends on how wide your wheel is... If you have 52mm with an 8" wheel, it's going to look much different than et 52mm with a 10" wheel.

 

That's correct, if the o/s stays constant, 1/2 the width increase is inboard and 1/2 outboard

 

The picture of your rear wheel does not seem to be a 9.5" with et52. Looks like there is room for more than 10mm ie needed.

 

Ron, did you buy those wheels from Paddock? If so those where the wheels that were on my Cup usa. Both front and rear need spacers on a 964. You will need a 1/4" spacer on the front and longer wheel studs. My cup had 20mm factory spacers on the rear and longer studs. Looks like you dont have the spacers .. will be too close the the oil line and need to be closer the the fender. I am guessing the fronts dont look right either without a spacer. Geoffrey and Joel Reiser helped me with sizing on these.

 

All that to say that you got yourself a nice set of wheels.

 

That's the set - very nice I might add... The front is fine for me, just the rear needs to kick out about 10mm for me to be happy. I'm not racing, just DE... What tires were you running such that you needed 20mm at the back - no rolled fenders here? How ironic, I had a set of 18mm adapters that I sold off last week not thinking I needed them - they pushed the MY02 rears to the limit and had et 65 vs et 52 for the BBS.

 

Well The cup came with the 20mm spacers. They are a factory RS part I think ... so you can get them from Porsche. Yes they are nice wheels. I had 275 on the rear and they fit fine. You may have to flatten the oil line .. which is pretty easy. You may not need to roll the rear fenders .. but that is also a pretty easy job. You can really stuff them in there. Good luck with the car .. it looks great. I will keep an eye out for you this summer.

 

OT did you get the car repainted and from which vendor did you get the brake ducts??