DHS928

Well my newly on the road 87 five speed, was bought with 22 year old tires! They got me from Marathon Key to Atlanta and some use while it got the top refresh and Kroon engine harness. So today it was time for new tires and four wheel alignment at Grand Turismo East. Well I got the tires but no alignment since the mechanic found a bent wheel and both front ball joints really worn. Well the car has 178k on the odometer so I guess that is no surprise. I have seen some signs of slight damage under the car while fitting the chin piece and installing the belly pan so I am guessing that is when the wheel was bent, he said it is not bad and can be fixed. My question is what wheel is this, he said it is a Porsche wheel but he thinks it was for a different model. They are 17” and the front and back are different widths. So what wheel is this?

Bent on the inside, he said not to bad it will be an easy fix. What do I call it?
Tnx
Dan

hacker-pschorr

Cup 1 Wheels

Most likely a replica by Mille Miglia, Borbet, or some other brand. Many copies of those were made. Most OEM Porsche wheels have the width and offset stamped next to the valve stem. Look on the back of the wheel, should be some markings of a brand, part number, offset etc....

https://marqued.com/listing/fff97b37...1-style-wheels
https://www.fvd.net/us-en/WCD901747T...-approved.html

FredR

The wheel style as Eric says is the Cup 1 design as fitted to the early [1992/3] GTS models. In OEM form the rears are 9 inch and the fronts are 7.5 inch as I recall.

Chances are you will find that the front wheels have an offset somewhere around the 52mm mark whereas the real deal wheels have an offset of 65mm and for a very good reason. The trained eye can [to some extent] tell the front offset just by looking at how the wheels sit in the wheel well. With 65mm offset the wheels have a more "tucked in" appearance whereas with 52mm offset they actually look "better" because they "fill" the wheel well better.

The generic aftermarket wheels were not after the 928 market but the general Porsche market and 52mm offset better suited the 911, Boxster and probably 944 crowd.

Mrmerlin

I have those same 17 in wheels on my 84 Ruby car, they are aftermarket Borbet.

Now its good the front end parts were replaced ,
I would suggest you drive the car for about 50 miles before you get it aligned ,
as once the suspension has been moved with no weight on it ,
then it will take time to settle.

NOTE make sure to tell the service tech that you dont want the car lifted prior to them aligning it ,
as this will throw off the front end toe enough that the new tires will wear to the belts on the inner edges in about 2K miles.

NOTE the WSM has a pull down procedure for the front end prior to aligning the front end, so thats an option.

I have done many 928 alignments and the 50 mile drive works great for me,
as the rest of the suspension also gets a chance to settle back into position.

Randy V

As those wheels are not original to your model year, you might consider upgrading to an 18" wheel. this provides improved handling (less tire side wall) and a much greater (and cheaper) selection of tires.

The 5-spoke Carrera Lightweight 18" wheels are a perfect offset and bolt right on with no fitment worries. Like these on my former GTS:

DHS928

Thanks all, good to know! I was looking to replace the steering rack first due to a small leak on the right. Now will go with the ball joints and hub bearings first to secure the front end. Then go after the rack leak. Will stay with the 17” for now with a fixed rear and will check out eBay and see what comes up.
Dan

Dads928

Opinions vary widely but the majority opinion on this forum is that 17 is the sweet spot. More tire choice than 16 and they look better. 18s look great but the diminished sidewall produces a harsher ride. The 928 suspension was not engineered for an 18 inch rim . 17s were put on the GTS. That’s as big as Porsche went. I have 18s on mine because they were on it when I purchased the car and they look great. I don’t mind the ride but it’s not as smooth on crappy roads as the stock size.

OZ Futura 18s

DHS928

They look great, but since I am looking for a nicer ride and I have to deal with the open road I like the extra sidewall to protect the wheels. Found an 17x9 on eBay so I will get it and have a backup rear, will also get a 17x7 and have both!

Mrmerlin

Hello Randy, how are you doing?
I think of you every time I make a Cayman Island Rum Cake.
Nice Bentley in your Avatar

Randy V

Hey Stan! Yes, the rum cake is always a winner.

The Bentley replaced the GTS. A bit of a step up but I will always have a fondness for the 928.

Mrmerlin

Randy V Cayman Island Rum cake, Use while working on your 928

Randy V

LOL - love it. Good memories.

Now back to Dan's wheel troubles (I still think the 18" wheel is the way to go - drive a 928 with 18" wheels before thinking it creates too harsh of a ride).