Porsche Enthusiasts Club Forum

Hello everyone and hope you're all well.
This is my first post and will probably be very simple stuff to the more experienced owners.

When i bought the car 1992 928GT a couple of years ago I could see it had the wrong wheels fitted ( Borbett alloys 7.5 x 17 et17 front and 9 x 17 et 23 rear ) as the front wheels were sticking out further than the wings though the rears looked ok as the car has the wide rear arches . Is it called a GTS body ? or another term I have no idea.

I started looking on you tube for any info about which wheels should be fitted and decided on D 90 16" x 7.5 et 65 front , 16 x 9 et 55 rears . The ones i got had had the tyre pressure sensors fitted and it turned out the car was fitted with the 17" tyre pressure system and the different sizes won't pass each other. So i got a set of Cup 1 17" x 7.5 et 65 front and 17" x 9 et 55 rears , the fronts looked ok but the rears terrible and i bought a pair of 30mm spacers to bring the rear wheels out and now look ok . After lots more You tube i must admit the large diameter wheels usually seen on the American cars do look good .
Can anyone tell me which set up i should have and what is the possible max sizes and et for the GTS body style ? ,thanks.

During the summer I took the car for the MOT which it past without problems , on the way home the gear stick lost connection with the gear box , luckily it was still in gear and i managed to get home . After getting the car up on blocks i could see the ball and socket joint at the front of the gear stick linkage had come apart , a large jubilee clip around the torque tube and gear stick linkage seemed to work while waiting for the new parts to arrive which i still have to fit.

And finally while driving on a very hot day the car seemed to run out of fuel , after letting it cool down for a while it started and ran for a while more , this happened several times while getting home . I changed the fuel pump relay but not had chance to drive the car since . Does the relay fail or should i be looking elsewhere ?

Many thanks Ralph

Are you certain about the model year of your car? The final MY for GT was 1991. From 1992 all 928s were GTS, so if you do have a 92 it's one of the very rare RHD manual GTS. As you say, the GTS body was different with the flared rear arches

The GTS came as standard with 17" wheels, with the offsets you've described. The wrong offsets you had on the original 17" wheels that came with your car would have had a bad effect on handling, tram lining etc.

The tyre pressure monitoring system was introduced in MY89 on the 928 only, having been tried out on the 959! It was discontinued by start of MY93. The first couple of years of GTS were equipped with RDK, and with 17" wheels that would have been set up for 36psi all round. The 16" wheels ran 36psi front, 44psi rear so you can at least use sensors — they're switches strictly — on 17" fronts from 16" front wheels.

People have successfully run 18" wheels on 928s, but it's not recommended! This article from Angus Fox's 928.org.uk page has chapter and verse on 928 wheel sizes, designs, offsets etc:

https://www.928.org.uk/articles/60-wheels.html

Just curious about where you found set of Cup 1s which are specific for 928s with those offsets?

On the fuel pump relay question yes they are the relay most prone to failure, as they switch the highest current. The other suspect relays are for ignition (EZK) and injection. You may have intermittent fuel pump relay so see how the new one behaves, after which we can look at other possible causes for cutting out. With 928s an awful lot of mysterious problems are solved by replacing one or more of those three critical relays.

Hello Stratford

Thanks for the info it was very helpful.

I've looked at the log book and the car was first registered 4 - 8- 92 and the first service was 8 - 10 - 92 so i can only think it must've taken a long time to sell when new.

As for the wheels i think i'd best check the numbers again before confirming them and i do find it difficult to see the difference between cup 1 and 2. I can confirm the spacers i bought for the rear wheels were 25mm not 30 mm as stated.

I have seen people on you tube saying the front wheels on a 928 need to have the correct wheels/tyres but the large dia do look good.
I don't keep the car where i live so with the lock down it may be a while before going to see it.

Thanks Ralph

Hi Ralph

Porsche model years run from Sep, so MY92 cars (sounds like this is what you have) were built from Sep 1991.

GTS models sold pretty well at that time. It was the outgoing S4 cars that hung around a bit (some MY91 S4 cars were not sold/registered till 1993), and the very last 1995 GTS cars which were also very highly priced by then - into six figures.

The Cup 1 and 2 designs are similar, but when you view them next to each other the difference is obvious. Cup 1s are smoother and more of an ‘organic’ shape. Not sure which GTS years were fitted with Cup 2 as standard - certainly by 1995. I have Cup 1 wheels on my S4.

Oh and welcome to 928 ownership! One thing that’s brilliant about them is the level of technical knowledge among owners, shared very freely.

Cheers, Adrian