adrial

Compared to stock wheels there will be 26mm more on the outside and 10mm more on the inside.

As it is with the stock wheels, there were slight rub marks on the plastic in the wheel well on the shock side...I think plastic is all it rubbed against though.

This is compared to the 17x8 ET 48mm, which will place 4mm LESS on the inside and 30mm more on the outside. These rub against the fender with 1.5 deg camber.

Shouldn't I be using tire width rather than wheel width, given that wheel width is going up .5 inches (from the 17x8), but I'm using the same tire??

According to tire rack, tire width for a 235/40/17 (should be same as the 235/45) kumho is 9.5", a 225/50/16 is 9.1"

Going from the stock tire to the 17x8 ET 48, gives me 12mm less on the inside and an extra 22mm on the outside.

Going from the 235 on the 17x8ET 48 to the 235 on the 17x8.5ET 56 gives me 4mm more on the inside and 14mm more on the outside...

Based on the numbers...it should fit, right?? Or based on experience does anybody know if it'll fit?

Danno

"Compared to stock wheels there will be 26mm more on the outside and 10mm more on the inside."

Yes, compared to your stock 16x7" 65mm-offset wheels, this new one will place 28mm more rim on the outside and 10mm on the inside. This should fit much, much better than the 17x8 48mm-offset wheel which has 30mm more on the outside and 4mm less on the inside.

The rim-width actually determines the sidewalls' location, but I think you're rubbing the corner of the tread right? What determines the tire's outside edge of the tread is the centerline (offset). Since the new centerline is 8mm inwards from before, the entire tread is 8mm inwards.

The problem here is in the difference between in offsets between a Turbo and TurboS. Most wheels vendors make the mistaken assumption that the wheels are interchangable between these two models. This is partially true, in that the stock wheels will swap back and forth no problem because you have plenty of clearance on the outside and inside with stock wheels. However, when you start increasing wheel-widths, clearances decrease and you have to be much more precise with your measurements.

The general rule of thumb I follow on front wheels with all 944/951 cars is:

stock offsets for stock widths of 7"
stock offsets+5mm for 1" extra width of 8" (moves wheel inwards)
stock offsets+10mm for 2-3" extra width of 9-10"

Russ Murphy

I've got 17x9's up front with 255 Khumo Victoracers and no rubbing problems on my '88 non S. I think the offset is 65mm. Once again Danno's right on the mark.

gilwong

Danno,

What is the widest wheel one can run on a 1986 951 without having to alter the lip of the fender and not rub with the possible lowering of the rear end. I will be running 17" wheels, currently have 7.5" up front and 8.5" rear. I want to put 9.0", 9.5" or 10" inch rims on the back. Does it make any difference if I run 2 or 2.5" difference in width between the front and rears? Look forward to your advice.

Ciao.

adrial

Thanks guys

So it sounds like a 235/45 on the 17x8.5 ET 56mm will fit...maybe even a 245...

I'm not sure if I should keep the current rear 17x9's (which are rather heavy...55lbs wheel and tire, BFG R1 255/40), or go for a lighter 17x8.5. Will a 17x9 with a 46mm ET fit a 275/40 (diameter 25.2") fit on the back?

Gilwong, more rubber on the rear while keeping the same on the front will cause the car to understeer more. I can't help you with max width without rolled fenders...

--adrial

Sami951

Adrial - 275 with 46 ET will not fit, I'm positive. Tommy (sybelix) has 265/35 18" ET 49 in there and it's very close; adding 5mm outwards for the rubber and 3 mm for the offset, it will definitely rub! And this is with the rolled fenders... you'll need more offset.

adrial

Sami, Thanks

FYI the 88 turbo s and 89 turbo have fenders rolled from the factory.

So it sounds like I might as well go for the 17x8.5 all around....

thanks again,
Adrial

Fast4525

I decided to add to this thread rather than starting a new one.


Will this fit without rubbing on a late model 951??


Front 17x8.5" ET43mm with 235/45-17 and -2 camber?

My proposed combo will sit the same to the outside (fender) as a 17x9.5" ET56mm wheel and I am sure people have reported using this spec with 255/40-17 or even 275/40-17 tires!



Rear 17x10" ET46mm with 265/40-17 or 275/40-17 and -2 camber?

I have seen people run 996TT 18x11" ET45mm wheels with 285/30 and 295/30 tires so my combo has to fit, right

Bob_in_Chicago

I run 17x 9 55mm Cup II with 255/40 tires without any problems on all four corners. This is a lowered 88 non S.

Dea_944t

My experience after trying quite a few combos is that an ET around 50 is the best at the front when fitting wide wheels if you also run some track-camber (2,5-3 deg).
I run OZ Futura 17x9 ET50 with 255/40-17 Toyo R888 without any problems on a late 951 (the late ones have rolled fender lips).

Important is also the actual measured total tire width, my R888 255/40-17 is 5-10mm wider than a 255/40-17 Michelin Cup.

/Dea

jasonlp

I run 17/9 47mm all around on a lowered 86 no issues, no rolled fenders

255/40