ThadJones12

Got a set of '02 C5 wheels for my 86... and then read on the forum that only the 90's c4 vettes were a straight bolt on

So where are good places to get a set of 3/4" adapters? I've heard the adapters are better than the spacers. I get confused over the whole hubcentric and lugcentric talk. I know what they mean, but what's best? Should I have both? I know 6061 is a necessity as well.

So in short, what and where should I get for adapters?
Thanks

DMITTZ

The C4 the early C4 corvette's (1987 and earlier) had a different suspension geometry and thus different wheel offset than the later 1988-1996 cars.

Your 86' will have the earlier style suspension.

When you put a wheel on your car you will notice there is a central hub that the wheel fits over. This hub supports the vehicle's weight - not the lug studs, the lug nuts/studs just fasten the wheel to the hub so that it does not come off the hub, but the hub supports the weight (at least it should).

When you put a wheel spacer on a car it moves the wheel out from the hub. If the spacer is thick enough the wheel will no longer rest on the hub and its weight will only rest on the lug studs rather than the hub, additionally most lug studs will not have enough threads to allow the use of a thick spacer.

Lug centric wheel spacers are basically just a flat disk that fits between the wheel and the hub, you should only use these If they are 1/4' or less thick.

If you need a thicker spacer the solution is to ad longer lug studs and use a hub centric wheels spacer. This type of wheel spacer fits over the car's hub and also have thier own hub that the wheel fits onto and support the car's weight. Wheel adpators are another option if you are using about 1' or thicker, you bolt them on using your existing lug studs/nut and they also have their own built in lug studs that you bolt the wheel onto as well as a built in hub.

Our cars use a 5x4.75 bolt pattern and have a 70.3mm central hub.

To determine the size of spacer you need for your new wheels look at the offset of your Original wheels and your new wheels, the difference between the two is the thickness of wheel you need.

Sorry if this was a bit long but I hope it helps get you started.

DMITTZ

I don't know off hand what the offset of the 02 C5 wheels you bought are but I don't believe they will bolt up to your 86' without a spacer/adpator. If you can tell us the offset of your new wheels we can help you determine the size spacer you need.

Once you have that info and the central hub bore (70.3mm) and bolt pattern (5x4.75) you should be able to find something cheap searching online that has the correct specs. No need to buy specialty ones as long as the specs are correct.

ThadJones12

I have done a little research and the offset is about 3/4" difference. The C5 should be the bolt pattern and hub size... right?

zr1fred

Ebay is your friend. Same bolt pattern.

DMITTZ

The C5 wheels have the same bolt pattern and hub bore

If you have determined that you need a 3/4 in spacer. Then I would recommend you get one that is Hubcentric as well as install longer lug studs and you should be good to go.

I agree Ebay is your friend.

ThadJones12

http://wheeladaptersusa.com/products/4-wheel-spacers-adapters-1-inch-5x4-75-chevy-camaro-corvette-s10-cts?variant=909510649

What do you guys think of those?

ex-x-fire

Those are adaptors. These are hub centric spacers that you would need longer studs. I like the second option. Less stuff to loosen, break, or seize.

ThadJones12

I've heard nothing but bad things about spacers

DMITTZ

You will need hub centric spacers.

I have hubcentric 15mm spacers and longer ARP lug studs on my 88' so that I can run the C5 Z06 wheels (18x10.5) all the way around and I don't have any issues and I race it plus drive on the street.

What is important is that the spacers be 'hub centric', not lug centric.

John A. Marker

The picture above is spacers.....basically 5 holes for the lugs to pass thru. An adapter will have five holes to accept the lugs on the car and then there will be 5 lugs sticking thru the adapter to bolt the wheels.

So the difference is that the spacer will provide a "filler" to space the wheels out from the axle....but all the weight is on the lug nuts which is not good. The adapter is bolted to the axle and then the wheels are bolted to the adapter. It is a snug tight well engineered product.

ghoastrider1

goode stuff here but my eyes are starting to glaze over

QCVette

Here are the offsets for the stock wheels.

Assuming the C5 wheels are non Z06 wheels, So to have the tire centered at the same location on the fronts it would be
56mm-32mm= 24mm adapter (about 1") if your car is non Z51
56mm-38mm= 18mm adapter (about 3/4") if if your car is Z51

and for the rears it would be
65mm-32mm= 33mm adapter (about 1 1/4") if your car is non Z51
65mm-38mm= 27mm adapter (about 1") if your car is Z51

If you are trying to get a flush fit to the fender edge, or a set distance from the frame you may want to measure the distance now and then calculate based on the offsets and wheel widths and allow for whatever tire "bulge" past the wheel edge,

Good luck.




84-87 base
16"x 8.5"- 32mm

84R-87 Z51
16"x 9.5"- 38mm

88-96 base
16"x 8.5"- 50mm
17"x 8.5"- 56mm
17"x 9.5"- 56mm

C5 base
17"x 8.5"- 56mm
18"x 9.5"- 65mm

zachaeous

I put a set of c5 wheels on my 1984. I used the spacers that were not hub centric. I would not do this again. I removed them and went back to the 16" wheels.

I did not like the looks of the stock wheels as well, but the car rode so bad with the larger wheels I did not enjoy driving it anymore. That is why I would not recommend not doing the swap. JMHO


Good luck with your decision.