kboustani

i have 16 inch wheels with 70 et.i also have a 25 mm spacers.witll this combo works in the back of my 89 c4?

altarchsa

bassam

think it does, i had ET 65 with 25mm spacer on 18" wheels.

Computamedic

Why is it that when people ask for advice about spacers, the most important part of the equation - the wheel width - is so often omitted?? Without knowing the width of the wheel it's impossible to give a meaningful answer. The diameter of the wheel is largely irrelevant in this instance.

A wheel having an offset of 70mm will be reduced to 45mm if using a 25mm spacer. It will fit (given that the width is acceptable) but whether it looks good will depend, again, on the width.

Dave

bassam

wheel width is very important, mine was a 10", I doubt KBOUSTANI is going to fit wider than that.

kboustani

good point.they are 9 s

Gus

Question - If the wheel width is 9 inches and the ET is 15 - can you machine down to a greater ET if there is substantial metal to work with. Reason I ask is that there are a lot of 944 / 928 wheels have a small ET, but it looks like there is enough metal to machine the center down to acceptable ET for the 964. Just wondering if anyone has done this?/

Computamedic

I'm having a hard time convincing myself that Porsche would specify the design of a wheel with so much excess metal as to leave sufficient "meat" for it to be machined out. Why would they put such an excess there in the first place??

The question has been asked many, many times in the past and I have NEVER EVER seen a reply which suggested that it was a good idea. Admittedly it's your life you're playing with but I don't think I'd be keen to put my life on the line in that way.

Regards

Dave

Gus

Dave - understand your thought pattern - and it is probably correct - I was just thinking that in todays world a manufacturer does not develop a cast for multiple wheels variables. Instead he has one cast and then machines the wheel to the specs desired for the car the wheel is to be mounted on.
Lets take a 9 x 17 Cup 1 - the same wheel designed is used on the 964/944/ 928 all with different ET's .
The wheel is cast, then cleaned. After coming out of the cast the ET may be a ET= 0 or dead center. Then the wheel is machined to the desired ET. The height of the center hub starts at one given height based on the casting. then the ET is cut. But it is manufactured with sufficient area depth in the center hub to accommodate all the variable ETs that are required.
Don't know if any one else can/or will chime in on this or not.

Computamedic

Gus,

It may be that your assumption is correct but I would offer an equally credible scenario which, personally, I think is more likely to be the case. A wheel design is largely about the centre part and I suspect the casting mould is designed to produce a standardised centre which can be varied in terms of it's position relative to the rim. In this way the same centre cast can be used to create a limitless number of offsets without the additional cost in time and material to machine the excess away. All that is required is to move the relationship between centre and rim. Multi-part wheels are created the same way, it's just that the two (or three) parts are put together after casting/machining.

Regards

Dave

Gus

Very viable - wish we had some real bases to go on -
So if your scenario is right then the position of the center hub and spokes ( for lack of better term) would vary in position to the out side rim. If it was a 50 ET then the center hub and spokes would be closer to the outside rim edge. And a 23 ET would have the hub and spokes set IN a little more, moved towards the inside rim edge.
Am I following you correct.

Computamedic

I think so.

Dave

ltc

FWIW, my 964 Euro Cup runs ET68's in the rear (OEM 9.5" 17" Cup 1s) with a 21mm OEM spacer (I probably have the P/N somewhere). Quite common for the Cup cars, just used longer studs.

kboustani

thanks for the replies.i will be using my 25 mm with th spare wheels i have.