Vipermn1961

Just bought some 17" turbo twist wheels from Brian Phillips from Rennlist (thanks Brian). I bought these for my 1986 928s, specs for the wheels are listed below. I've already removed the rear spacers in order to run the 16" Fittapaldi wheels i currently have on the car and i would like to know what's the largest size tires i could go both front and back with no interference.

New wheels
7" x 17" ET 55 (996.362.124.00)
9" x 17" ET 55 (996.362.128.00)

Current wheels
Front - 8.5 X16 with a +52mm offset or a 6.8 in back spacing (tires are 225/50/16)
Rear - 9.5 X 16 with a offset of +44mm or a 6.98 inch back spacing (tires are 245/50/16)

joejoe

I am running 275/40 rear and 225/45 front on 17x7 and 17x9 twist wheels on my '81 and 275/40, 235/45 on one of my '86.5's et for both are 55

James Bailey

The 7 inch width of the front limits you to 235 maybe 245 depending on the tire. Much more than that and it will handle very poorly as the too wide tire flops from side to side on a narrow rim. The sidewalls need to be straight up and down or slightly V for best handling. You never want them pinched in at the bead, never But you see it all the time !! Good news is as the tire tread is lifted of the road at low speed there is lots of noise and the driver feels like they are really cornering at the limit, how could anyone possible turn faster ?

Vipermn1961

Do you have the factory spacers on the cars or no?

anonymousagain

same here for SATA with factory rear spacer and no rub.

James Bailey

plenty of rear room for a 275 , I run 295, even some 305 with a bit of fender rolling and a spacer ! the rear is easy

joejoe

No spacers, open lugs on the '86.5 with original lugs cut to hide the long studs

Vipermn1961

THANKS! Looks like i'll go with 235/45/17 front (no spacers) and 275/40/17 rear (no spacers). Ought to look good on the new wheels!

joejoe

You might want to go with 225 up front (i wish I had)

Vipermn1961

Why were they too big?

joejoe

The ones with 225 seem to have straighter sidewall, tires are khumo asx

James Bailey

Go to tire rack select a tire and look at "Specs" the maker of the tire states the range of rim width for each size....a 235x45x17 needs a 7.5 to 9 inch rim !! 7 inches is too narrow if you ever plan to go around corners