18" RUF Speedlines on 78SC Euro Advice Needed

[acapella8]

I just got a killer deal on an 18 x 9.5 RUF Speedline rears. (less than $200 including shipping)

I have a 78SC Euro (already low).

1. What is best advice for mounting these wheels?
2. Do I need rear spacers -- what size?
3. What range of tire sizes should I be looking at?

Forgive so many questions, but the deal was too good to pass on -- but now I need some advice on how best to implement.

[PorscheGuy79]

Tom, I got your email...im not good with the big rims but let me go ahead and shoot around what I can figure...

As far as mounting wheels, that depends on the offset of the wheel. Do you know if they are made for a 79-89 car? Or are there offsets made for 964...993? They are most likely for a 993 or 964 which isn't bad but its just not ideal. What you will most likely need are wheel adapters (not spacers) from somewhere, I know Wheel Enhancement sells them but im not sure which are good and where else to find them. Also I would put money on you having to roll the rear lip of the flair to stop them from rubbing...cause thats gonna be TIGHT. Thats all my knowledge can give but try and find someone who has gone down this path already.

Conveniently there is a thread that might be able to help you out, or at least point out some guys who have walked a similar road before.


18" on narrow body Carrera


Good luck Tom! As usual...we should get dinner sometime.

[ZAMIRZ]

Those are meant for the 964 and as such, will need pretty thick spacers to fit. You might be better off selling them for a profit and getting the 17" RUF wheels.

[acapella8]

So for an 78SC, would I be looking at 3" or 4" spacers most likely?

I'm not quite sure what my next step should be....

[buster73]

Great deal. If the offset is around 18 mm, the 9.5x18 might just fit. Tires would be like 255/35/18.

[acapella8]

Thanks Guenter, The offset is 18mm as it's included with documentation. Is there a guide to tires?

What size in spacers would be best to investigate?

[PorscheGuy79]

Call Wheel Enhancement they should know which to use because the offer wheels like that quite a bit and should know which would work in your situation.

http://www.wheelenhancement.com/index.php?t=AccSpacers

[acapella8]

Thanks Matt for the link/info. I didn't know they specialize in Porsche, been a bit confused searching today on Tirerack and others, as I don't get a comfort level with them.

Going to call them on Monday!

[efhughes3]

Sell them. IMO, it's not worth the effort to get them to fit. You're going to have a compromised setup at best. On top of that, an 18" wheel looks too big/bling on an SC, IMO.
what will you do for front wheels? 18" up there will be really fun.

[Bill Verburg]

If those are truely +18mm ET wheels then they will bollt on w/ no spacers needed, tire should be a 265/35 @ ~25.3" or a 255/35 @~25". For the front you want ~ +25 - 30 mm ET 8s w/ ~25" tire
probably a 225/40 if you stay w/ 18s.

The question is are they really +18s?

[PorscheGuy79]

FYI Tom, PCA rules I believe state no spacers for DE events, so if you want to get out on the track you might want to think about making sure you dont have to use spacers and/or keep the stock wheels. If Bill is right, which he probably is, then those wheels woud work allright. Even so I would keep the stock wheels for at least one track event to make sure the 18s dont light up your fender lips.




That said our PCA tech inspections are...not that intensive.

[Bill Verburg]

19.5ET w/ 275/40 tires gives you this much room on the inside after the bolts have been shaved



265 will likely have a tad more clearance but it depends on the tire, they are all a little different.

[Bill Verburg]

+18 moves the tire 1.5mm outboard from the above shot.

The 275/40 also required lots of work at the lips to give the necessary clearance.

[acapella8]

Thanks Bill - thanks for the great pics. That's far too close for my blood for sure. 1.5mm considering pressure differences, cornering shifts etc.

I think I may need to sell these after all...

[buster73]

With 9.5X18 and 18 mm offset you should not need spacers. Ruf built these wheels to sneak them into the narrow body cars (meaning non-turbo). Attached picture shows 9.5x18 (18 mm offset) with Dunlop 255x35x18 (tire can make a difference in clearance) . You might have to roll the fender lips and increase camber a bit, but otherwise they should fit. Of course Porsche warns not to use 18" wheels on pre-964 cars but there have been threads on this issue before.

[acapella8]

They are 18mm offset, I checked the box again today.

Wow. Just when I think I may need to get rid of them.

Guenter - did you try others before settling on Dunlop 255x35x18s? I'd be curious to know of your trials.

Matt - Yes, I'm definitley keeping the stock fuchs, I love them and will keep them for my first DE's this spring for sure.

[maxnine11]

.... just by looking - and knowing what car that style of wheel was meant for, I doubt the wheels have a 18mm offset (regardless of what the box says)
Most Ruf wheels I have seen have the offset cast near the valve stem or on the inside of the wheel. It will have the letters "ET" and the offset number.

max

[buster73]

Unfortunately the car in the photo is not mine, but I know that they tried Dunlop, Continental and Michelin which all fit (255x35). If you follow Bill's advice regarding tire dimensions you should be fine. Problem is that tires of the same size (e.g. 255x35x18) might still have slightly different overall dimensions and shape of the sidewall. Check the manufacturer specs (e.g. tirerack) to see the difference or compare the tires at your tire dealer if they have them on stock. As shown above, 265 or 275 are a really tight fit and one tire might fit and the "same" tire from a different manufacturer might not.

[PorscheGuy79]

Tom, basically it comes down to the million dollar question...

How much do you want them?

I dont think its impossible to get them to work, but there will be some hang ups and some problems. For one thing our cars come from a time when Porsches were hand built, and as good as that can be its not perfect and is open to human error. What tire and wheel width might work for one, may not for another without modifying fenders, bolts etc. So basically are you really set on the look or are you in to the wheels because of the price?

[PorscheGuy79]

Originally posted by buster73
Unfortunately the car in the photo is not mine

Yes thats not his, unfortuneatly Gunter cant talk about his personal car for fear that his garage mates might be listening in...its way top secret.