davidcross
New member
I have a 1995 C4 with 17" cup alloys....will i need to add "spacers" or the like to fit 18" turbo or techno wheels?
18" Alloy Wheels
- Thread starter davidcross
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davidcross
New member
So concise u have totally confused me! its a yes with no spacers then?? just slot right on??
Yes, providing you purchase the correct Narrow Body (NB) wheels I quoted.
Just be careful when buying as there are a wide variety of Cup 3 (Turbo/Techno) wheels out there. Front are generally the same accross the 993 range, although there is a 7.5j front. Rears are a little trickier as they come in various widths and offsets.
If you're after a new or refurbished set then speak to ChrisW as he deals in these wheels and will make sure the offsets are correct.
C.
davidcross
New member
Very helpfull tks. So theres a chance i can keep the front alloys i have and just get rears by the sounds of things. Then just get the whoel lot refurbed
davidcross
New member
Will do top man
Andy B Aces High
New member
David, Check out the technical section at the top of the forum as when fitting 18's you also need to install a brace across the steering rack fasteners.
Andy B.
Andy B.
Andy B Aces High
New member
The article is in FAQ's, title "Important Retro Fit of 18in Wheels". The part number of the brace is 993.347.131.02.
Andy B.
Andy B.
davidcross
New member
Tks Andy. I'm gonna speak to the guy mentioned on this thread although he is a long was from where I live.
38F3E1
PCGB Member
Make sure you get the right wheels as there are wheels out there with a 993 part number that are not for a 993. Specifically the 7.5 inch fronts with a 993 part number are not for a 993 as they are really too narrow.
As posted above the correct sizes are
Rear 10 inch width ET (offset) 65
Front 8 inch width ET (offset) 52
The 10 inch rears for the wide body cars have an ET (offset) 40 and these cannot be fitted to a narrow body car.
Ian.
As posted above the correct sizes are
Rear 10 inch width ET (offset) 65
Front 8 inch width ET (offset) 52
The 10 inch rears for the wide body cars have an ET (offset) 40 and these cannot be fitted to a narrow body car.
Ian.
orangecurry
New member
Opinions differ - I have the 7.5J fronts. The car handles very well.
As the car was specified with 7J fronts, I can't see how 7.5J is 'too narrow'.
As the car was specified with 7J fronts, I can't see how 7.5J is 'too narrow'.
davidcross
New member
Tks Maurice. Ive decided once the tyres need replacing then the wheels will be changed. I had a real expert over today who confirmed the wheels i have are not original wheels although the preious owner had the car 6 yrs and confirmed they were on the car when he bought it from an OPC. The ones i have are offset and protrude slightly rather than look flat as per the official ones. Ill be after 18"s carrera cups when i replace and not turbo wheels.
orangecurry
New member
If you mean 'at the factory', I didn't say they were?
I don't understand your comment - could you explain please?
orangecurry
New member
Snide repost? A Porsche OPC fitted the 7.5J wheel to my car, which is why I clarified your point for you.
Am I on the 'right' forum? Odd question as I'm providing some information on wheels fitted to the 993. You can argue about whether they were fitted at the factory, or even by an OPC, but as they are commonly fitted to the car, (and perform well) the information is both valid and useful.
Your last comment about optimal tyre widths on a rim is erm how can I put this.... wrong.
Accepted knowledge is that a 7.5 rim is a match for a 225 width tyre. For instance Porsche supplied them as such on the 996 and Boxster.
Am I on the 'right' forum? Odd question as I'm providing some information on wheels fitted to the 993. You can argue about whether they were fitted at the factory, or even by an OPC, but as they are commonly fitted to the car, (and perform well) the information is both valid and useful.
Your last comment about optimal tyre widths on a rim is erm how can I put this.... wrong.
Accepted knowledge is that a 7.5 rim is a match for a 225 width tyre. For instance Porsche supplied them as such on the 996 and Boxster.
orangecurry
New member
Oh dear.
I've kept everything factual, as can clearly be seen above. You don't seem to be following your own rules.
You said:
A 225 should have tread around 8.85" wide, so already quite wide for an 8" wheel. Putting that on a 7.5" wheel is not optimal, period .. [8D]
Its not just a Porsche thing, its basic matching of wheels and tyres ..
So you are not going to admit you are wrong? I guess not.
I've kept everything factual, as can clearly be seen above. You don't seem to be following your own rules.
You said:
A 225 should have tread around 8.85" wide, so already quite wide for an 8" wheel. Putting that on a 7.5" wheel is not optimal, period .. [8D]
Its not just a Porsche thing, its basic matching of wheels and tyres ..
So you are not going to admit you are wrong? I guess not.
davidcross
New member
I wish I hadn't started this!!! Time to move on gentlemen. I'll b taking the little beauty to duxford bank holiday weekend so I Can get some official verdicts then. Cheers
38F3E1
PCGB Member
David.
There are a lot of interconnected facts around wheel size. It's not just the relation of the tire size to the rim size but also suspension set up. The effects on the suspension of toe-in, camber angle and ackermann angle are all affected by the rim size and offset fitted. Another effect is that rim size and offset will determine how far within the rim the lower balljoint sits on the front suspension and this effects the geometry and handling behaviour.
If you stick to the factory recomendations you know the car is operating as designed at the factory. Incorrect sizes are not going make your wheels fall off, and you may not be able to notice the difference. It's personal preference but the factory are very clear what the standard is.
Also Porsche make in the Cup 2 17" wheel and the Hollow Spoke Turbo 18" wheel two of the best and lightest wheels available with the correct offsets. Unfortunately they are not the cheapest, especially the hollow spokes. If you like 17" and want relatively cheap you cannot beat genuine Cup 2s. Many owners would say that on typical british roads the 17" is the better wheel to fit.
Ian.
davidcross
New member
Yup ive already been thinking that its the suspension i may want to adjust more than anything. To me there seems a gap between the rear wheel and the wheel arch thats bigger than it needs to be so an adjustment to the suspension may address this??? BEst place to get this done?
38F3E1
PCGB Member
The gap between the rear wheel and the wheel arch is determined by the wheel. There is no adjustment in the suspension to change the gap. Wheel spacers are the only way to change it.
The common size for 17" rears is 9" rim with 55 offset. Depending on the size and offset you have you could have a bigger gap. You should get to see a few 993s with 17" if you are going to the show to compare.
Ian.
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