I need to replace a D90 style wheel. Its ET is 9 52

Can I use a 52.3?

How much difference is there?

Does anyone have a 52?

 

Front or rear?

 

The 928GT with Design 90 wheels has a 9 inch rim with ET52 on the rears.

There is an 8 inch Design 90 rim with ET52.3 - that has a 964 part number.

Obviously one would not fit an oddball sized wheel but you could run with a pair of them. No idea if that wheel has the RDK kit capability

 

He wouldn't be the first person to try and put the 9" D90's on the front, hence my question.

 

Nothing wrong with your question whatsoever - I dare say folks have driven around with half an inch of rubber sticking outboard of the fender and wondering why there was a rub.

Given the OP is talking about a single damaged wheel I would tend to assume he is smarter than that. Thus I addressed the question the OP asked.

 

The largest fronts fitted on the GT were the 89 GT/88 CS wheels which were 8 inch and had an offset of ET 60.

As for 964/944 D90s, they did not have the RDK.

 

If the other wheels were 8", that 52.3 is 0.3mm different tin offset - that's a rounding error, which means the 1" width difference gets split equally internal and external to the existing wheel, so 1/2" closer to the strut and 1/2" poking further out. If the original wheel was 8.5" it's 1/4" further in and out.

 

So now im thinking about buying a completely new set of wheels as it seems unlikely that I find a 16x9 52 D90 replacement and the other three are in really nasty condition.
what does anyone think about going to 17" Cup wheels ?

Like these here:

https://www.rosepassion.com/en/parts...-3159-0-258643

 

I suspect those wheels are Cup 1 replicas as the original items are something like US$5000 a set. Most likely they will not have the RDK sensors fitted [not that I consider that an issue].

The front offsets are incorrect- with a front offset option of 52mm they will fit but as I am concerned they will not "work". The offset is required to keep the car travelling in a straight line if you hit a condition that induces yaw such as standing water on one side of the road. To be clear the chances of needing such are slim and ET52 should give you a slightly better corner handling characteristic. If you do go for them do not get ET47 option for the front wheels whatever you do.

On the plus side the Cup 1 look is classic Porsche and looks period correct- the wheels also have TUV approval which is essential for Germany [as I understand].

 

I have the Cup 1 replicas, Mille Miglas, with those offsets. I use a rear spacer to bump them out some, but they fit just fine in the fenders, front and back. No rubbing or handling issues. I think they are the best looking and best performing wheels for the 928.

 

So Im hearing 17 inch wont be an issue for rubbing etc.

The fronts on the Cup replicas are 8 ET47 I think.

That the RDK is no longer functional doesnt matter too much.

Im more concerned with safety and good handling.

 

ET47 is too low an offset on the front and will cause rubbing issues.
8" ET52 is doable. Higher ET would be better.

 

I have Mille Miglia Cup 2 replicas.

Fronts are 17 X 7.5 ET52

Rears are 17 X 9 ET47

No spacers, rubbing, or handling issues. They also clear the larger rotors in the front. Hope this helps.

 

Agreed; for 17" cup 1's, you need 52 offset for front, and 47 for rear. That's what I have. No spacers needed. However, I use spacers on the rear to bump them out some.

 

Kevin,
thanks - this helps alot.
best,
G