TraceZ

Hello forum friends,

I'm looking for some wheel and tire advice. I just bought a set of C5 magnesium wheels in fair condition with usable tires mounted for $600.

Sizes are:
Rear 275/40ZR18-994 Michelin (These are run-flats on the rear) About 1 season of wear left on the rear tires.

Front 245/40ZR17-91W Kumho (Not run-flats but lots of wear left)

I've managed to get them installed on the car. I had to use a brake hone to remove the slight lip from the inside of the rear hubs to get them to fit my car, but it was no big deal. The car drives like a different car it is so much more stable and easy to steer. It doesn't wander all over when the road is uneven the way it used to. It's really quite refreshing to have it drive the way it should again.

The wheels and tires I removed are Chinese made a-mold C4 Corvette ZR1 replicas with old worn out Firestone 28540ZR17 tires.

These front wheels weighed 11.5 lbs less each, and the rears weighed 10 lbs less each for a total 43 Lbs of un-sprung rotating mass.

The magnesium 18" rear tires are a but taller than what I had on the car. I can tell the rear of the car sits a bit higher now, and it looks like the wheels could use a small spacer, but the back is acceptable as-is.

The magnesium 17" front tires seem to be too short and sit inwards way too far. There are no drivability problems, just appearance issues. The front fender gaps are huge. My car has stock springs.

I did notice the Khumo tires on the front are not the correct size for an OEM Corvette. They are 245/40ZR17 when in fact they should be 245/45ZR17.

I'm also thinking it needs some wheel spacers in front.

Am I on the right track? Get the right size tires and put some spacers on all around? Has anyone run these wheels and what did they do? They sure do look great on the car, I'm really excited to get them setup correctly.

And some pictures of the wheels purchased:




Thanks for your advice,
Tracy

TraceZ

digging into this more.....


I'm thinking the right size tires to run here are

rear : 275 40 R18 - 26.7" tall

front : 245 45 R17 - 25.7" tall


as opposed to the front tires which are currently 24.7" tall 245 40R17.

I'll pick up a full inch in height on the front wheels.
That, and a couple 1/2" spacers and I think it will do the trick.

What are my best options on spacers, and opinions on all this?

Injuneer

Do not stack spacers. If you want to add 1" (if that's what you mean by "a couple 1/2" spacers) , you have to use an adapter. The billet aluminum adapter bolts to your stock studs with the supplied lug nuts. Then the adapter has its own set of studs to bolt your wheels to, using the stock lug nuts.

I wouldn't recommend any more than 5/16" on a single spacer. Even that requires longer studs.

TraceZ

Yeah, when I said "a couple" I meant one on each side.