Rear rim sizes and fitment questions

38F3E1 · Jul 20, 2006

A couple of quick questions regarding rear wheel rims

My car currently has 17" 8J ET52 rims fitted at the rear (7J ET55 at front). They are genuine Cup 1s with the size/offset stamped by the valve stems.

So my questions are

1/ Would early 964s have had this rim rather than the more common 9J ET55 rears?

2/ I am going to keep my eye out for some 9J ET55 Cup 1s for the rear and if I find any do I have to make any mods to the car to fit them? Were there any changes made to later year 964s for fitment of these wheels?

3/ If I change the rears can I fit the now spare 8J ET52 rims to the front instead?

BTW the current 8J ET52 rears already have the same tire size as that fitted to 9J ET55 rims.

Ian.

Dave Wilkinson · Jul 20, 2006

Ian,

As far as I can see (on PET), the 9J ET55 wheels were fitted to the Turbos and the TL cars - not the NB cars. The 8J ET52 seemed to be the standard 17" rear wheel for the >92 MY NB cars. There were also 9.5J ET68 wheels for the Turbo and TL cars but they were fitted with spacers and longer wheel studs. I'd guess you'd be OK with 255/40 tyres on both 8 and 9J wheels. I don't know if there would be a clearance issue with the 9J wheels on a NB car - I somehow doubt it, but it would be worth checking.

You may have a similar clearance issue if you fit the 8J wheels tto the front. You'll need narrower tyres for the front (225/45).

Hope that helps.

Regards

Dave

38F3E1 · Jul 20, 2006

Dave.

I was guessing 9J ET55s would fit because you see lots of 964s fitted with Cup 2s and 9J ET55 was the size I thought Cup 2s came in. However now I think more about it I have seen different size Cup 2s fitted to the rear of early 993s so perhaps this is what people use when fitting Cup 2s to 964s.

Anybody out there with Cup 2s fitted? and if so what are your rear sizes and offsets?

If you look at Adrian Streather's list of wheels for 964s then 9J ET55 Cup 1s are listed and it doesn't say which model but you are suggesting only wide body cars can take these wheels.

Ian.

Dave Wilkinson · Jul 20, 2006

ORIGINAL: ian_uk
If you look at Adrian Streather's list of wheels for 964s then 9J ET55 Cup 1s are listed and it doesn't say which model but you are suggesting only wide body cars can take these wheels.
Ian.

Ian,

I'm not suggesting that - I just suggested caution. I suspect the 9J wheels are fine but since my car is different in that area I've got no basis on which to judge. My car has turbo arches and 10J ET47 wheels on 28mm spacers!!

Regards

Dave

38F3E1 · Jul 20, 2006

ORIGINAL: Computamedic

I'm not suggesting that - I just suggested caution.
Regards

Bad phrasing on my part .... I was suggesting you were suggesting in a helpful way rather than a negative way.

Ian.

Jamie Summers · Jul 20, 2006

Yes, no problems with 9J Cup 1s wearing 255/40/17 on a narrow body (even lowered) car. This is what I have on mine. 8s on the front could be a squeeze - the RS ran 7.5 and had rolled wings. If you run a lot of neg camber and spacers on the front you might get away with it, but I suspect not with anything wider than a 225 tyre. I run 215 on 7 inch fronts with a 6mm spacer without clearance issues (running RS geometry but no rolled lips).
Generally those who run Cup 2s use 9 and 7 ET 55 same as the Cup 1s.........

Jamie

Dave Wilkinson · Jul 20, 2006

ORIGINAL: ian_uk
Bad phrasing on my part .... I was suggesting you were suggesting in a helpful way rather than a negative way.
Ian

Ian,

I didn't - don't worry about it. Jamie's input is far more useful since his car is NB.

The problem on the front is the wheel contact with the chassis on full lock. The factory did introduce slightly larger (10mm) stops to reduce the lock which solved the problem but it may not be enough with 8J wheels. I have 8.5J wheels on mine (with 18mm spacers) and don't have a problem - but that's a very different situation to a NB car.

Regards

Dave