17" Cup Wheels on 928S4?
#1
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17" Cup Wheels on 928S4?
Hello,
I found nice Cup Wheels. They are actually from a 993.
They are 7Jx17 ET55 and 9Jx17 ET55.
Would they fit on my S4 (without rolling!) and what would be the right size for the tires?
Thanks 1000x
Volkmar
I found nice Cup Wheels. They are actually from a 993.
They are 7Jx17 ET55 and 9Jx17 ET55.
Would they fit on my S4 (without rolling!) and what would be the right size for the tires?
Thanks 1000x
Volkmar
#2
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That is indeed the setup for the 993. The 928 version had 7.5" front wheels with ET65 - the 7" ET55's will fit, though. Not sure on what tires to run on 7" fronts (the 7.5" was fitted with 225/45/17), the rears came with 255/40/17.
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Not ideal ... 928s are under-tired in front already on 7.5s and going to 7s makes it worse. Also, the lower ET number reduces the car's designed-in negative scrub radius (http://en.wikipedia.org/wiki/Scrub_radius)
#4
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They will bolt on and 'fit', but the front isn't the best choice. The 993 came with a 205 section front tire on that rim IIRC, with 255 rear on those wheels. A 225 is better for the front and probably the max you'd want to install on the 7" rim.
#6
Burning Brakes
225x45x17 in the front and 255x40x17 in the back
I have exactly the same setup and it works + looks perfect.
Lots better than the previous imitation cup II's I had with ET 47.
Cheers
I have exactly the same setup and it works + looks perfect.
Lots better than the previous imitation cup II's I had with ET 47.
Cheers
#7
I have the same 993 Cup wheels on my '89 GT with 225/45/17 front and 245/40/17 tires in the rear. 255/40/17 is not available in the Michelin Pilot Super Sport and the 245/40/17 tire is almost exactly the same diameter (.14% taller) as the 245/45/16 tires that came stock on the S4. 255/40/17 is 1.42% taller than the stock tire.
My car has exactly the same width tires as the OEM 16" set up so there is no concern for me with adding width to the rear and not the front as with 255 rear tires. My tire setup will have the same balance as the factory intended.
The 10mm difference in offset is a minor change from the 928 Cup II wheels. The 993 Cup wheels are 7" vs. 7.5" for the 928 Cup II. This means that the outside edge of the front 993 ET 55 wheels is roughly 4mm farther out than the 928 ET 65. I think this looks perfect and is a small enough difference from stock to not be of concern.
My GT has factory 17mm spacers on the rear and rolled fenders. The 245/45/17s in the rear are close to the fender, but don't ever contact it. A regular S4 or later GT without the spacers & rolled fenders should have no issues with fender contact even with 255 width tires.
My car has exactly the same width tires as the OEM 16" set up so there is no concern for me with adding width to the rear and not the front as with 255 rear tires. My tire setup will have the same balance as the factory intended.
The 10mm difference in offset is a minor change from the 928 Cup II wheels. The 993 Cup wheels are 7" vs. 7.5" for the 928 Cup II. This means that the outside edge of the front 993 ET 55 wheels is roughly 4mm farther out than the 928 ET 65. I think this looks perfect and is a small enough difference from stock to not be of concern.
My GT has factory 17mm spacers on the rear and rolled fenders. The 245/45/17s in the rear are close to the fender, but don't ever contact it. A regular S4 or later GT without the spacers & rolled fenders should have no issues with fender contact even with 255 width tires.
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#9
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You will NOT be happy with how the 55 offset tracks on the front of your car. I have tried it and it was terrible.
I have 65 offset 17s on the front and 10 inch wide 18's on the rear. is the perfect combo..... though not cheap.
I do have a set of 18s @ 8.5 with a 52 (I think) offset I put up for sale here several months ago and got zero interest, which tells you something.
I have 65 offset 17s on the front and 10 inch wide 18's on the rear. is the perfect combo..... though not cheap.
I do have a set of 18s @ 8.5 with a 52 (I think) offset I put up for sale here several months ago and got zero interest, which tells you something.
Last edited by Gretch; 11-12-2013 at 11:30 AM. Reason: corrected stats on MM wheels
#10
Are you sure the tires weren't the problem? I've seen massive differences going from unevenly worn 235 width tires to new 255 width tires on my Audi. The 255s tracked extremely well when I expected them to tramline much more. The excessive tramlining I had been experiencing was due to the worn 235s not the width.
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Thanks for all the interesting comments. I can get them for $ 475 - wheels only. There are scratches on the rims so they need to be refinished. Still a good deal?
#12
#13
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In regards to the 928 series 86.5 onwards with 993 cup wheels on the front ( ET 55 ) and with new tires , they drive OK ish , until the new tyres bed in ( say 5,000 miles later or so ) & the dreaded tram tracking becomes quite noticeable , then as the tires get even older ( rolling resistance of the tires increases ) the tram tracking gets even worse .
Naturally , if the current owner of a 928S4 with 993 55 ET cup wheels ( that a previous owner fitted ), then this owner knows no better & thinks that is how these Porsche's drive ,meaning his 928S4 tramtracks & has nervous steering ( owners description ) , we know because we had a customer here a year ago ( aprox ) with exactly that ,then we fitted the wheels of my 928S ( 65mm offset ) & I asked the 928S4 owner to drive it & he felt the difference .
Normally this is the thing we see with 928S4's with the old Mille Miglia 17" Cup copies with their 52 ET ( which is even worse on a S4) , but this time we had the 993 fronts & with its half worn tires it was very similar to how the Mille Miglia wheels felt like to drive , meaning it tram tracked to the point where it would be hard to live with ( compared to the 65mm offsets that have no tram tracking at all )
Naturally , if the current owner of a 928S4 with 993 55 ET cup wheels ( that a previous owner fitted ), then this owner knows no better & thinks that is how these Porsche's drive ,meaning his 928S4 tramtracks & has nervous steering ( owners description ) , we know because we had a customer here a year ago ( aprox ) with exactly that ,then we fitted the wheels of my 928S ( 65mm offset ) & I asked the 928S4 owner to drive it & he felt the difference .
Normally this is the thing we see with 928S4's with the old Mille Miglia 17" Cup copies with their 52 ET ( which is even worse on a S4) , but this time we had the 993 fronts & with its half worn tires it was very similar to how the Mille Miglia wheels felt like to drive , meaning it tram tracked to the point where it would be hard to live with ( compared to the 65mm offsets that have no tram tracking at all )
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I wouldn't do it.
I run 245 fronts and 275 rears on 18" CLWs - much improved handling.
Think about the 993 and why they want fat tires in the back and skinny tires in the front.
The 928 does NOT share the same characteristics.
Wait for a set of 18" Carrera Lightweights or 996 wheels. Much better offset and waaaay more tires to choose from in 18" size.