Luke714

Hello,

I posted a while back asking about ZR1 wheels, with everyone's help I did a little more research and figured out about what I needed for offset and tire sizes. This is my current setup plan, I would love to hear opinions and know if anyone sees some red flags.

This is on an 86' 951 with an LS1, that's sorta why I want as much rubber as possible without hardcore fender rolling or a WB kit. Some minor rolling as necessary is fine with me.

Front:
255/40R17 Kumho Exsta XS
ZR1 17”x9.5”, 56mm offset, 5x120.65 bolt pattern
Final Offset to be: 35mm
.827”, 21mm spacers needed with a 5x130mm to 5x120.65mm bolt pattern conversion

Rear:
295/35R17 Kumho Exsta XS
ZR1 17”x11”, 50mm offset, 5x120.65 bolt pattern
Final Offset to be: 25mm
.985”, 25mm spacers needed with a 5x130mm to 5x120.65mm bolt pattern conversion

I'm planning to purchase adapters from this company: http://www.motorsport-tech.com/

so what does everyone think?

catamax944

I think you will need to roll the rear fenders and double check that rear spacer ,with those 11" wheels and 295 tires you can eaasily rub the inner fender.
I have 10.5" x 17 57mm offset with 28mm spacers ,i got half an inch left from the wheel to the inner fender ,check fit with no tires.

Luke714

hmm, if you're right about your clearances I would be about .4" closer to the inner fender than you. Leaving me about .1" for the rim since 295mm=11.6" the tire would rub.

Good call, thanks.

Does anyone else have some measurements between rim and inner fender along with their offset numbers? I'd love to measure my own car, but I'm currently in Alabama and my car is in Maine :P

DVC

Why not just use 996TT wheels? It's already been done and you won't need adapters.

Luke714

I know I know, I was really hoping to stay no bigger than 17". Call me picky. I've also got a really good deal on the ZR1's.

But, I'm still interested in the option. I just tried looking for the offsets on those wheels and had a surprisingly hard time, what are the 9 and 11" wheel offsets? Also, when you say no adapters you'd still need spacers right? What are the final offsets? Any links to threads with the people running 996 wheels on a 86 951 would be appreciated.

Most of my information was based off this thread:
https://rennlist.com/forums/924-931-...44t-951-a.html

read through it, sounds pretty convincing that what I have listed will fit

Luke714

It seems like "will these wheels fit", "what size tires can I use", etc etc type threads are one of the most rapent subjects on car forums. Problem is, you turn around and one person says "oh yeah, those'll be fine" and the other guys says "no way". It's one of the most frustrating subjects to get good information on and filter through the billions of opinions, so if anyone has the be all and end all answer please let me know. So far everyone here has been the most helpful and informative!

I'm sure I'm not the only guy a little bemused by all the information floating around about this. That's just my little rant........

xsboost90

996tt wheels- 18x9/11 - 225 fronts/295 rears. 86 turbo early offset. Used 1/4" spacers up front and on spacer on the rear-dependent on which way your rear suspension is shifted and camber you may or may not need spacers. Close to inner/outer wheel wells w/ rolled fenders. Also ran 525lb coilovers which prob. kept them from rubbing more.

Speedline 18x9/10 - 245 fronts/265 rears. Converted car to late offset- no spacers but w/ 50mm offset needed some camber in rear to clear wheel wells-although the car already had 3.5 rear camber so no issues.

BBS Sport Classic2's -18x8/9.5 late offset n/a fit w/ only front spacers to clear hubs 1/4"

Boxster twists - late offset n/a fit w/ no issues- front spacers? cant remember

Cup 1 replica wheels- heavy- early offset on early offset turbo- rolled rear fenders to keep from rubbing. 17"

DVC

Regarding the 996TT wheels; they are very inexpensive and easy to find. You can get the hollow spoke version and end up with a fairly light, OEM wheel setup. As long as you can stand the "twist" styling. Search the classifieds here and at 6speedonline.com. You'd be surprised what little money they bring.

18x11 ET45mm
18x8 ET50mm

Do a search for user xsboost90 (Dan). He's extremely helpful and ran this setup on his '86. He can tell you what spacers to run. Realize that all 944s are somewhat different when it comes to nailing the offset. This is further exacerbated by attempting to adapt the GM wheels - which, to my knowledge, hasn't been done yet.

Not sure I read your plan right, but the adapter alone will act as the spacer. The advantage of using the OEM Porsche 18" wheels, is that you don't need adapters, you will have more tire choices, and slightly nicer look. The difference in ride between the 17" and 18" wheel is negligible, in my opinion. It took some planning and work, but I do like the 295s on my LS swap.

DVC

LOL, Dan beat me to it. Told you he was helpful.

Luke714

Thanks! What size spacer did you say you used on the rear for the 295's? Why only 225's on the front with that setup, is that really all that could fit?

So did Danno find some overly optimistic information:
https://rennlist.com/forums/924-931-...t-951-a-2.html

Also, what is meant by 2.5" coilovers? I know it's a dumb question, is that the inner diameter of the spring, outer diameter, spring perch diameter? Aren't most coilovers you buy going to have approximately the same spring diameter?

These are what I have from Ground control http://www.ground-control-store.com/...p/II=77/CA=219, the springs are tiny compared with the stock springs. Once again, I'm away from my car so I can't measure them directly

Luke714

Beautiful cars btw! Some new posts popped up while I was replying, thanks!

Yeah- I know adapters are also spacers. I wasn't sure if you were saying that you wouldn't even need spacers.

xsboost90

oh- the early offset on the turbo w/ the twists required about a 1" spacer up front. I had bolt on adapters but i eventually installed long studs and pulled the studs from the adapters and made them into slide on spacers. The rear needed 15mm spacers on the ps at first, but after i pulled my rear suspension and pulled the torsions and went full coilover it needed 5mm on each side...since the suspension can slide side to side some.

Luke714

yuk, I guess I didn't realize that the rear suspension could be so un-symmetrical. What was your limiting factor on the front keeping you to 225's? I'm mostly interested in your 295/225 setup :P