F451

Don't know, but I'll try to check later today and report back.

IcemanG17

Do you have any pictures of the wheels-tires on the car...say pointed straight and at full lock both directions?

http://www.1010tires.com/WheelOffsetCalculator.asp

Using the stock wheels as a comparison your setup will be 38mm CLOSER on the inside (thats plenty) and will stick out 38mm MORE on the outside (I think that will rub)....

My 18x10x88.9mm (9 inch backspacing) front wheels with 295/30 tires are 61mm CLOSER on the inside and 15mm MORE on the outside....it doesn't rub anywhere even at full lock, but I am running double rack stops.....

Heres a pic

F451

Finally got a chance to check ride height on my '88 S4:

Front Left: 168 mm (2mm lower then low limit)
Front Right: 171 mm (1mm in tolerance of low limit)

Rear Left: 197 (14mm higher then high limit)
Rear Right: 197 (14mm higher then high limit)

Factory specs:
Front: 180mm +/- 10mm
Rear: 173mm +/- 10mm





For reference I used Tony's excellent write up to check my ride height. Thanks Tony!

http://members.rennlist.com/v1uhoh/checkingRH.htm

Note: I've mounted different wheel/tire sizes front to back and left to right to compare offsets on the front and back with the different wheel/tire sizes that I have with the goal of running 10" wheels all around.

Here's my wheel/tire sizes, just to keep all the info in one post:

Front Left: 18 x 10", ET 65: 265/35 - 18
Front Right: 18 x 8 1/2", ET 52: 245/40 ZR1

Rear Left: 18 x 8 1/2", ET 52: 245/40 ZR1
Rear Right: 18 x 10", ET 65: 265/35 ZR18

F451

After the suspension settling for over 70 miles here's my rubbing results:

Front Left: 18 x 10", ET 65: 265/35 - 18: Only rubs on full lock left - parking lot situations - need to double check where the rub is coming from, but I'm not worried about it at all as I rarely go full lock.

No rubbing at speed over bumps or bumps in turns (yeah!).

Front Right: 18 x 8 1/2", ET 52: 245/40 ZR1: No rubbing on full lock either way. Slight rub at speed over big bumps in turns, but only on big bumps - not sure where the rub is.

Rear Left: 18 x 8 1/2", ET 52: 245/40 ZR1: No rubbing at all.
Rear Right: 18 x 10", ET 65: 265/35 ZR18: No rubbing at all.

F451

Here's pics of the different wheel/tire combos, but I forgot to take the full lock pics. Will try to get them later today or tomorrow.

Notice that the two different wheel/tire combos have the wheel sticking out pretty much the same.




Front Left: 18 x 10", ET 65: 265/35 - 18: Only rubs on full lock left - parking lot situations - need to double check where the rub is coming from, but I'm not worried about it at all as I rarely go full lock.

No rubbing at speed over bumps or bumps in turns (yeah!).












Front Right: 18 x 8 1/2", ET 52: 245/40 ZR1: No rubbing on full lock either way. Slight rub at speed over big bumps in turns, but only on big bumps - not sure where the rub is.











More pics here: http://edb.smugmug.com/gallery/9285085_K9S6S#P-1-20

F451

Rear wheels, no rubbing at all.

Left Rear: 18 x 8 1/2", ET 52: 245/40 ZR18






Right Rear: 18 x 10", ET 65: 265/35 ZR18

F451

Next step is to order up some new tires for the 10" wheels, am planning on going with 265's up front, and 275 or 285's on the rear.

Then get them mounted, settle the suspension a bit, set ride height, then get an alignment.

I also need to figure out which finish to go with as the rear wheels are painted silver and need to be refinished, and the fronts are polished and need refinishing. I'm leaning towards painting them silver.

IcemanG17

Ed
Great write up....... Great data really...... I would run the 18x10x65mm all around....run the 265/35-18 front and go a bunch wider in the rear, say a 295/30-18 rear or keep the "square" setup all around, but run a spacer to push the rears out more so there isn't so much gap to the outside of the fender..... On my race car with the welded in GTS flares + fender rolling & 335/30-18 rears I run around a 1/2" spacer...

F451

Thanks Brian. And yes, I've decided to definitely go with the 10's all around, and as you mentioned, 265's up front, 295/30 - 18's on the back.

Again, thanks for all the input guys, its very helpful. -Ed

kccampro

Let me know what 10" wheels you go with... I may do the same.

F451

Wheels or tires?

I've already got the wheels, will be ordering tires soon. Right now the leading contender is Kumho Ecsta SPT. It looks like a good combination of price, availability, and performance.

I'm on a tight budget (not working right now), otherwise I'd be considering a number of other tires.

kccampro

Yeah, I was wondering which wheels you went with. You may have already posted it and I just mised it. Twists... I see it now

SwayBar

That has to be the all-time most sinister looking 928 picture with those big meats on the passenger-side being shoved up into the fender-wells:


Awesome looking car!

The driver-front tire reminds me of my last set of fronts on my racecar where I wore the insides down to the cords on both. I think I may have too much camber at -2.5.

dprantl

Your picture of the left front 10" wheel shows the tire sticking out well past the fender. If you drive hard enough into a corner, the fender will contact the tire at the tire's highest point. That, or you have some super stiff springs! And that's the basic problem. You want wider wheels in the front so you can corner harder/faster, but then you can't because you will ruin the fender if you corner too hard.

Dan
'91 928GT S/C 475hp/460lb.ft

F451

We'll see. I tested it pretty thoroughly though. Lots of big speed bumps while turning, straight on, running at speed on the roller coaster roads out here, large dips and bumps in corners, hard braking, etc. No rubbing with the 265's at all.

Also keep in mind that the wheel angles inward as the suspension and wheel travel up (or the body moves down), so just because the wheel looks like its sticking out a bit, doesn't necessarily mean it is going to contact the fender under compression.

And others have reported no problems running that size in this thread.

I will be sure to report back once I get everything mounted up and an alignment done. Probably another couple of weeks.