Hi everyone. I appreciate this topic may have been dealt with to death - it deals with offsets and the usability of other Porsche rims on a 928.

I have just purchased a set of 993 rims. They are 16". The fronts are 7.5", with an ET55 offset. The rears are 9" with an ET70 offset. Do any of you out there, who have a much greater knowledge than I, have any comments or quips about potential fitment issues.

Hope to hear from you soon.

Tuk

 

they will fit, but you will probably want spacers to push them out a bit, especially in the rear.

 

The fronts won't need spacers though.

 

My experience is that the stock 21mm spacers on the 84 push the outside edges of these rear 9" wheels against the body.

You will need to roll the fender lip or procure some spacers that are somewhat less thick.

 

what size tires are you going to have if the rims fit? 225 front and 275 rear?
i also have a 84 and i do want to change rims and tires in the future so once it's done ...love to see some pics
Barry

 

with the ET70, you'll still be short to the fender.

Our Blue Car, 1980 with 38mm spacer -
9" with ET55 hits by ~10mm with 275 tire
8.5" with ET50 is right at the limit with 255 tire...very slight lip roll and perfect no rub.

ET70 is a lot to make up, so you'll want a bit more spacer than 21mm, to sit at the fender edge.

 

Now I am confused because there seems to be conflicting opinions being expressed here. There seems to be a consensus that there is no issue with the front rims. As to the rear, some seem to say the rear wheels will be a bolt-on fit; others that a spacer is necessary, and others over the size of the spacers.

At this point, to the extent the spacer aspect deals with the placement of the wheel within the well, I am not concerned about aesthetics, and how it looks sitting in the well. My only concern is whether the rear wheels will rub against the outer wheel well or the brakes or the interior.

I admit I am so d*mned confused about the whole offset thing, I am lost.

Finally, as to the tire widths, I understand I need to keep the diameter as close to 25" as possible so as to not screw up the speedo readings. Suggestions are welcome.

 

I made a mistake. 55 offset 9" 993 hit my fenders on the rear with spacers.

You were speaking about 70 offset rear.

 

In order to really understand what it is about, let see the OEM wheels. On a '89 GT rear wheels are CS design 9x16 ET 60 with 245/45/16 tires. Those wheels are mounted with a 19mm spacer to fit correctly. Later model was mounted with 9x16 ET 52,3 "90 design". Those wheels seem to seat more underbody as the CS design and it is abvious as the "real" ET of those wheels is lessen by 11 mm

So for the rear, it seems that under certain condition the min ET is near 41 mm and would increase by 5 mm as you mount larger and larger tires.

For the front, there is very little space to mount whatever wheels you want. OEM parts are ET 60 wheels in 8x16 for the CS design wheels and those wheels really flush the fender. Normal ET is 65.

Puyi

 

Does anyone actually have their rims and tires changed on the 84 and earlier and let us know the size and offset? Thanks

 

VIS1GOTH - the ET70 will not hit the fender lip and will fit over the stock caliper just fine.

Once mounted, then you can address the look.

Tires: 225 with 255 are a match, but 255's in a 16 are limited, so you may have to stick with only 245's to have any choice.

Edit: seems closest will be 225/50 with 245/45. TR has these in a decent ZRi Fuzion.

 

Thank you anonymousagain for the clear and direct answer. Will post pics of the car once the rims arrive and are on.