Str8boostin

Injuneer, first of all I just want to say you're one hell of a member when it comes to sharing your wealth of knowledge. Remind me of myself on the audio forums

Anyway, I picked up some C5 rims with tires.

Fronts are; 265x40x17
Rears are; 295x35x18

Front went on just fine, no rubbing nothing.

The rears slightly rub the inside, and I mean they BARELY rub the undercoating under the wheel weld.

I just want some peace of mind here, are 5/16" spacers ok to use with these rims? I only ask cause I've never used spacers on any other car I've owned. Guess I'm just being too paranoid about the nut loosing that 5/16" of space when bolted down onto the rim/tire.

I just installed the spacers and haven't driven the car but I hope it was enough to clear the tire. If not, would something slightly bigger work and be safe?

Here's the car -

Injuneer

Those appear to be the C5 Z06 wheels. They are extremely deep, and are almost certain to cause problems:

Z06 - 18x10.5" 58mm offset = ~8.00" backspace = rubbing on most 4th Gens

Another possibility would be hammering the inside fender liner.... see the FAQ where I show what needed to be done with my car when using 17x11.0" (7.93" backspace) ZR1 wheels with 315 drag radials. You also run the risk of the inside of the rim catching on the jounce bumper bracket when you jack the car.

As far as spacers, I'm not really into using them on the rear axle. To me, it puts more bending stress on the studs. Without the spacers, the load is a combination of shear stress at the face of the hub from the torque load on the wheel, and tensile stress from the nut being tightened. Add the spacer, and now the torque load of the wheel is moved outward from the face of the hub, and adds a bending stress to the stud.

Probably OK on the street, but I wouldn't use them on the track. Others will tell you they use them at the track.... but it's just up to the individual at this point.

If you are using a spacer, you will probably need longer studs. The tech requirement is that the nut engage a length of threads equal to the diameter of the stud. Since you have 12mm diameter studs, there had to be roughly a 1/2" of nut threads engaging 1/2" of stud threads. Note that the nuts are deep enough that this does not require that the stud end be flush with the outer surface of the nut.

I would get a set of high strength ARP or Moroso M12-1.5 studs, about 1/2" longer than stock. I believe the factory knurl is 0.509".

Str8boostin

I'll dig out the rubber mallet later today

Not really enjoying the idea of using spacers but I don't drive the car hard anyway.

Str8boostin

Anyone get rubbing with their front tires with these rims?

C5 rims on 265/40/17 and during hard turns I have get minor rubbing under the wheel weld/plastic shield.

Injuneer

Surprising, since a 265/40-17 tire is actually narrower and a smaller diameter (25.3") than the stock tires (25.7").

As far as the width/offset of the front wheels, they are 1/4" deeper than your stock WS6 wheels, and stick out toward the fender 1/4"..... no reason they should rub on anything, unless your front end is lowered.

I've run front wheels with the full 275/40-17's, some with deeper backspace, and some with more frontspace, and the ONLY time anything ever rubbed was when the front end was dropped 1.8", and the steering was at full lock, and I hit a bump, all at the same time.

Str8boostin

Should've posted a pic, but here you go -





I was surprised too because it didn't happen immediately after installing my tires/rims but I guess I was just being too 'delicate' in my driving.

Normal driving habits are IN and I'm getting minor rubbing as you can see, more often when I turn left than right. Again the rubbing is minimal however being in the cabin (and as the driver) it sounds louder/worse than it really is. I can't get used to the noise and I keep getting paranoid as if I messed something up.

Now here's the fun part; I installed my UMI strut brace since it arrived today.

I Love the improved steering response however, I'm getting even more rubbing from up front.

Think an alignment would do the trick? I was thinking about it...even though my car doesn't pull one way or another so much especially with the strut brace installed but...IDK I'm at a loss. Alignments aren't cheap plus I doubt it'll resolve the minor rubbing issue?

What do you think Injuneer? Get rid of my tires/rims and put the stockers back on? I'd hate to do so back and forth because the damn lug nuts are weak and the corners are giving in..think I'm going to buy some new lug nuts tomorrow just to have handy.

PS Car is stock height.

Str8boostin

Here's the brace installed BTW as well as my SLP lid.

Bet you guys aren't used to seeing a stock engine bay as much

Injuneer

Try pulling the plastic fender liners forward.

Again.... small tires, near stock offset... can't explain, other than the caution that's in the post on fitting the 17x11's - these cars vary a lot and where some people can fit the 11's with no problems at all, others have to do the multiple fixes that I did. First time I've seen this problem in the front though. Are you sure your springs aren't sagging? With the smaller diameter tire, the gap between the tire and the fender should be very slightly larger than stock.

Str8boostin

Yeah I've done several searches before I even bought the tires and heard of minor rubbing in the rear.

No one, as far as I know, has problems with their front tires.

I tried pulling the liners forward but there's nothing to hold them there.

Would it be ok to remove them and cut them or leave them out completely? I ask because I don't know how effective the plastic liners are. Fortunately, on the driver's side the liner looks to be separate with that of the splash guard that covers the alternator.

Str8boostin

So I found out why the hell the rubbing was so loud even though I only saw minor rubbing on the plastic fender; the tire pushed the plastic fender inward a bit and it was rubbing against the steering knuckle!

Firewall is to your right in this picture as you look down the engine bay. Follow the knuckle and there you'll see a dark spot on the plastic, that's the plastic fender! Guess I should take them out if I plan on keeping these rims.

JETMAN95Z28

I'm looking into a set of C5 wheels for my 96 Z/28. They aren't Z06 wheels, just the standard C5 wheels. I haven't seen any info on mounting a set on a stock height car. I only have Koni's and BMR SFC for suspension mods. Any idea of the width/offset of these factory C5 wheels, and what size tires would be best for the rear w/o any major mods? I have the 275/40ZR17's on my car now so I would keep them the same on the front.

Injuneer

C5 FACTORY wheels vary from year to year (97-99 vs 00-02). But they generally do not cause problems.

The 00-02 fronts are 17x8.5 58mm offset. That gives about a 7.0" backspace, and that works OK. Frontspace will be less that 2.5" and that puts the outside edge fo the wheel/tire a bit further out than the stock 16x8.0" wheel and about 1/2" less than the stock 17x9.0" WS6/SS wheels. So, no problems.

The 00-02 rears are 18x9.5" 65mm offset. That gives about a 7.75" backspace, which will be close to the inner fender, but shouldn't be a problem. The outer edge is not a problem either, because that will be midway between where the stock 16x8.0" wheels are, and the stock 17x9.0" wheels. The best offset for the 9.5" wide wheels is in the range of 49-56mm, so the C5 wheels are just about 1/3" deeper than they should be. Still, no problems.

6SpdLT1Z

Those chrome Z06's look good on your black WS6.