Tyre Sizes 8/9.5 x 17 "Cup Car Cups"

[65 mat]

ORIGINAL: Hacki Use 225/45 x 17 front and 255/40 x 17 rear. Watch that you need the original 21mm spacers for the rear due to the offset. Neutral balance no problem with these sizes, it depends on the set up (ARB, camber, toe in, corner weighing, etc.) Not too much experience with wet weather tyres. Hope that helps, Hacki P.S.: These sizes are also the recommendation of the factory for road legal Cup cars.

QUESTIONS? Why didn't the factory use Magnesium "Cups" (as used on the RS and N-GT) on the Cup Cars and why didn't they have the above wheels manufactured with the correct offsets, so eliminating the need for spacers and extended wheel studs? Did the Cup Cars come with the extended wheel studs as standard? Cheers, Matt.[]

 

[Hacki]

ORIGINAL: 65 mat QUESTIONS? Why didn't the factory use Magnesium "Cups" (as used on the RS and N-GT) on the Cup Cars and why didn't they have the above wheels manufactured with the correct offsets, so eliminating the need for spacers and extended wheel studs? Did the Cup Cars come with the extended wheel studs as standard? Cheers, Matt.[]

Matt, years ago I read that these wheels were designed to stand the extra torture of close racing over the curbs as they are definitely stronger than RS mags. 8" and 9,5" due to slick tyre dimensions, long studs yes (otherwise no way to put those rear wheels on). Rear offset, why? No idea. I can only guess that maybe brake cooling is better with the spokes further to the outside (??) Anybody else? Rgds Hacki

 

[pncarrerars]

I think that it is more likely that they just used what was in the parts bin. Pete

 

[65 mat]

ORIGINAL: Hacki

ORIGINAL: 65 mat QUESTIONS? Why didn't the factory use Magnesium "Cups" (as used on the RS and N-GT) on the Cup Cars and why didn't they have the above wheels manufactured with the correct offsets, so eliminating the need for spacers and extended wheel studs? Did the Cup Cars come with the extended wheel studs as standard? Cheers, Matt.[]

Matt, years ago I read that these wheels were designed to stand the extra torture of close racing over the curbs as they are definitely stronger than RS mags. 8" and 9,5" due to slick tyre dimensions, long studs yes (otherwise no way to put those rear wheels on). Rear offset, why? No idea. I can only guess that maybe brake cooling is better with the spokes further to the outside (??) Anybody else? Rgds Hacki

Sounds like sense to me Hacki!

 

[65 mat]

ORIGINAL: pncarrerars I think that it is more likely that they just used what was in the parts bin. Pete

I agree that this is a common method with Porsche, however those wheels are specific (have their own part numbers) to the '90/Early'92 Cup Cars...I think [8|][]

 

[timarnold]

I might be completely wrong in this particular case, I'm just guessing, but where a racing series is involved it's not always down to the manufacturer it's very often specified in the rules by the club running the series, and the governing body (MSA/FiA) and what wheels are allowed is often decided with running costs in mind; so Hacki would be right in that durability will be a factor and so would actual cost of the wheels as genuine magnesium wheels would be much more expensive than aluminium alloy ones. In other classes like for example the Golf GTi championship, steel wheels are compulsory on the race cars where the equivalent road car may well come with alloys as standard or at least an option. The manufacturer may have little say in what is allowed but will have to produce cars that comply with the regs.

 

[Melv]

ORIGINAL: Hacki In Spa you better watch out for a Cup car in full camouflage and a determined guy with steel helmet and that certain "I´ll be a hero soon face" behind the wheel..... Oh, I forget, don´t mention the war. Hacki mitdemnolongerwhitenowcamouflageCupcar

Sneak preview of Herr von Hacki's new Uberwagen:-

And BTW, I didn't mention the war!![]

 

[Melv]

ORIGINAL: 65 mat ........those wheels are specific (have their own part numbers) to the '90/Early'92 Cup Cars...

The 'Cup' wheels were especially commissioned by Porsche. Roland Kussmaul's philosophy when designing the Carrera 2 Cup cars to race was to reduce weight. The new wheels saved a total of 11kgs...... PS Matt -do you have to wear a tinted visor when you drive your car......[]

 

[chfs911]

Did I mention I have set for sale! ;O)

 

[Melv]

ORIGINAL: chfs911 Did I mention I have set for sale! ;O)

You did........[8|]

 

[65 mat]

ORIGINAL: Melv

ORIGINAL: 65 mat ........those wheels are specific (have their own part numbers) to the '90/Early'92 Cup Cars...

The 'Cup' wheels were especially commissioned by Porsche. Roland Kussmaul's philosophy when designing the Carrera 2 Cup cars to race was to reduce weight. The new wheels saved a total of 11kgs...... PS Matt -do you have to wear a tinted visor when you drive your car......[]

Welding goggles Melv![8D]

 

[pncarrerars]

What are the cup wheel part numbers? I thought they were off a 928. Pete

 

[chfs911]

965 362 126 01 965 362 128 05

 

[65 mat]

That may be a Turbo part number actually. I know Ian964 has a couple of sets...what part numbers do you have Ian? Perhaps you are right Pete? Hacki...where are you?[8|] I think my old ones did have the same numbers Charles.