chris1

On my 1986 Convertible, it looks like the previous owner messed up a little; it has a set of 1987 rims with the charcoal center sections, however, it has (2) 9.5" rims on the rear, and (1) 8.5" rim on the driver's front, and (1) 9.5" rim on the passenger's side front; on my RPO sticker, it lists option PW9, which I believe indicates cast Aluminum Wheels - 16 x 9.5"; my question is should they all be 9.5" for all 4 rims? I spoke with a Corvette recycler, and he said that he thinks there should be (2) 8.5" rims on the front, and (2) 9.5" rims on the rear; can anyone definitively answer this question on whether they should all be the same size rims (all 4 9.5"), or should they be different on the front and rear?

Thanks

WVZR-1

The PW9 wheel code for your '86 would have been 4 - 16 X 9.5" with two being LH mount and 2 being RH mount. The wheels were directional. I'd say to determine what you've actually got remove them and let's check the casting information on the back-side of the wheels.

The PW7 option in '87 was also for 4 - 16 X 9.5 (2) LH & (2) RH.

lkl2005

I am pretty sure the stock rims on my 86 coupe are all the same size.

corvetteronw

Per my Cor-vette specs C4 book by Mike Antonick:
Standard wheel rim size: 16" X 8.5" front and rear. RPO Z51 wheel rim size: 16" X 9.5" front and rear.
All convertibles came with the 16" X 9.5" wheels both front and rear whether they had RPO Z51 or not.
"Wheels had a new look with a bright center area and argent gray paint in the spoke recesses." These are the correct wheels:

For 1987: "Exteriors were virtually identical to the 1986, except that wheel centers were argent." These are the correct 1987 wheels:

dphilC4

Agreed all the same on all 4 corners. Z51 came with 16x9.5, enkei made them I believe, if not z51 then 16x8.5 on all four.

JrRifleCoach

As I understand the RPO's,
The 84's Z51 package had the 8.5 & 9.5 mixed width wheels.
The mix caused a lot of debate since the tires could not be rotated.
They fixed that in 85 or 86 and made all four the same width. ie 8.5 or 9.5

Looks like someone sold the car off and kept their custom wheels.

WVZR-1

The OP's question was directly related to his '86 'vert and had nothing to do with the Z51 package at all. He mentions the RPO PW9 and that RPO specifies 4 - 16 X 9.5's. The OP has as he suspected a mismatch on one front wheel.

Regarding the wheels mentioned in the rest of the thread, they're not relevant to the OP's question but all parts publications for '84 specify 8.5 fronts and 9.5 rears and the RPO was PX2. I don't believe it had to do with any "package" regardless of what is publicized. In '85 the same wheel style was used and then I believe base cars got 8.5's X 4 and the Z51 I believe got 4 X 9.5's

Here's an excerpt from a 7/83 SPO publication and I've a 12/83 that displays the same. Not until '85 does it mention rears in 8.5 - in early C4 SPO publications "EXPORT" only production wasn't mentioned and I believe that even "EXPORT" Z51 cars as well as base cars got 4 X 8.5 wheels because of the 4mm additional width of the 9.5's:

[IMG][/IMG]

You'll notice the 15 X 7 & the 15 X 7.5 never released are cataloged, they are all the way through '84 SPO publications but are missing in the '85 SPO publications.

pmihaltian

All 1986 convertibles came with the 16" X 9.5" wheels on both the front and the rear. The wheels had a bright center area and argent gray paint in the spoke recesses. The valve stems were black rubber with flat black metal caps. Each wheel was identified with a casting mark indicating "LEFT SIDE ONLY" or "RIGHT SIDE ONLY" as appropriate.

Here is a photo of the correct 1986 Indy Pace Car 16"x9.5" aluminum wheels:

c4cruiser

RPO Z52 cars in '87 (both coupe and 'verts) got the 9.5" wide wheels. For '88, Z52 was still an option, but 88 was also the first year for 17x9.5" wheels and 275/40-17 tires as optional equipment; 16" wheels were still standard. Z51 cars got the 17" wheel tire package.

chris1

I didn't want to multi-quote every response, however thanks to all very much for the replies; I forgot I had Mike Antonick's "(Cor)Vette Specs" book, and after looking in it, it has pretty much contains everything in these replies; it looks like all the 1986 convertibles came with the 16 x 9.5" rims on all 4 corners; it looks like I will looking for an '87 rim for now; if anyone knows of someone that has a complete set of '86 rims available that are in decent shape, shoot me a quick PM....

Another quick clarification I came across is whether to set the tire pressure at 35 psi as recommended on the door placard, or the 30 psi that is recommended in certain GM publications to help soften the ride a little bit; it probably doesn't matter that much either way, however it rides pretty stiff now, and any little thing that could help is welcomed; starting at 35psi, after some driving time, the pressure probably heats up to 37 or 38 psi; starting at 30psi, they probably would be at 32 or 33 psi after some driving time; any thoughts are welcomed........

pmihaltian

I always ran my C4 with 30 lbs of air. Seemed to ride, corner & track well. However, even with the lbs @ 30 psi, the tires still seemed to wear a little more in the center (a sign of over inflation). I'm sure this wear would be even more pronounced at 35+ psi not to mention a harsher ride.

chris1

Pm: My thoughts exactly; I took it for a ride today, and it seems a little better at 30 psi; I will leave it there for now and see how it goes.....

pmihaltian

Had mine @ 30 psi for 27 years and it worked fine for me through all road and track conditions.

JrRifleCoach

Well, excuse me Mister OEM Wheel Expert!



We where attempting to help the OP too.

mike2977

I've got some serious scratches to process out of the original wheels on my '84 coupe. Based on the above, I could purchase 16 x 8.5 original wheels from a number of sources, but if I want to keep my present (new) tires, what aftermarket wheels would fit and look good?