darth

Hi All

Were OEM Cup 1 wheels made in Italy and if a Cup 1 is made in Italy can I be sure they are OEM? What is the ideal offset for a 7J and 9J 17
inch Cup 1 wheel and will an offset of 55 for both front and rear be OK with 205 / 50 and 255 / 40 Kumho ESCTA tires? I remember a recent thread which gave this info but I can't find it and I seem to remember an ET of 47 on the rear and 52 in front being ideal. I know this info is probably in Adrian's book but I don't have it near me. Currently I have the 928 6J 16 inch front and rear rims and I'm experiencing some scrubbing on the turn in with 205/55 tires and I'm concerned if I get anything wider I'll see more scrubbing.

Thanks in advance
Bill
90C

Andy Roe

55 front. 47 rear.

Christer

these are the very wheels i have...errrr....i mean had on my C2 and 55 offset front and rear did not cause me any problems whatsoever. In fact I believe the offset on the rear should be 52 not 47. Go for it, but make sure they are not heavyweight aftermarket wheels....and how do you do that? Good question....

Andy Roe

I had ET55 wheels on my C4 & they rubbed the oil line in the wheel wheel arch. 5mm Spacer fixed the problem. Wheels now on my C2 are ET47.


Where's Adrian when you need him!!

Christer

yeah C4's are funny that way. And accident damaged cars...

darth

Thanks for the responses so far.

I'm wondering what an OEM lightweight rim/tire combination would weigh - anyone know what I should expect if the rims are not the heavy weights and have a tire comparable to the above mentioned Kuhmo's? I can't imagine there is much variance in weight between brands or how much they are worn.

Thanks again in advance
Bill
90C2

joey bagadonuts

Ask the owner to weigh them (if they don't have tires on them).

A lightweight Factory wheel/tire combo comes in at or below 40 and 45 lbs front and rear. And yes, there is a difference between tire weights:

DaveGordon

Hi,

To quote from the 'Streather Source of Knowledge':

Approved wheels for 964 series:

(just the Cup design 92 listed)

7Jx17, ET55
7.5Jx17, ET55 (need spacers)
7.5Jx17, ET65 (need spacers)
8Jx17, ET52
9Jx17, ET55

Hope you don't mind, Adrian.

Also, I believe on OEM wheels, the offset appears next to the valve.

I have 2 sets, both 7"/55 and 8"/52 which fit on my C4 fine...

Dave.

DaveK

As "the book" is the reference for most things - I wonder how long it will be before you can actually get the whole book by cutting and pasting answers in rennlist!

ian c - u.k

that's what i'm hoping to do !!!!
save £50.00

adrian has this scam covered by his "see my book " standard answer .

adrian , you doing this is not helping me !!!!!!!

Cupcar

The Cup style wheels used on the rear of early Cup cars were 9.5" X 17" ET 68 wheels which required longer studs and a 21 mm rear spacer, effectively resulting in a 47 mm offset.

Later Carrera Cup cars used 3 piece 9.5" X 18" wheels with a 47 mm offset and required no rear spacer.

Maybe that is where the 47 mm came from mentioned above.

Kahdmus

Realize the humor on offer here but still hafta say that I have never seen Adrian state this 'in place of' an answer. Maybe in addition to an answer or 'for extra information please see the book.'

Adrian

Actually it was Alois Ruf who worked out the 47 mm offset wheels first. First available in 1990 in 17 inch and then in 1992, 18 inch for the RCT.
Then they was copied by PAG but not for road use
Ciao,
Adrian
964C4

BGLeduc

FWIW, I have Millie Miglia Cup 1 replicas in 7.5" and 9"x17 size.

I don't know what the offset is, since they were on the car when I got it, but have made an inquiry to Tire Rack, since they appear to be a vendor for these wheels.

I can say that the rears do not appear to rub anywhere with 255/40 Kumho Ecsta Supra 712's. The fronts (205/50) DO foul the inner wheel well at full lock (just like the photo in Adrians Book).

I have yet to fit the steering stops or spacers.

BGL

darth

Hi All

Thank you for your responses they've helped tremendously.The P/N stamped on the back of the Cup 1's which were originally on an 87 944 Turbo is 965.362.128.00 - I know this is a Porsche P/N but does this assure me that they are in fact OEM and are light weight? The back of the spokes are cupped out and I'm still waiting to have the weights of them in order to compare with the listing above.. Will my center caps off my 928 style rims fit these Cup 1 rims?

Thanks in advance
Bill
90C2