houston_aggie

Was thinking about switching to non run-flats for my next tires, and building a mount in the rear to carry a spare. The spare would need to be no wider than the available clearance between where the top is secured in the truck area. My question is, will a 17" rim fit the vette? Or, because of the front calipers (mine is a Z-51), is an 18" rim the minimum size to clear those and the rotors? The rim doesn't have to look all fancy either. Just enough to get me on the road again without having to call AAA in the event of a blowout.

2LT-Z51

this is a really good question.... the bolt pattern is shared for most of GM's 5 bolt cars.... however no other car has 18's... a Camaro will have 17's...

took a quick look at my SS Camaro wheels (17's)... they will not fit on the vette's front wheels (maybe the back)

space saver tire?? did a C5 ever have one??

it might be worth it to get a 18 inch wheel x 6 inches wide and get a tire that would fit that....

i guess if you want it bad enough anything can be "custom made"

thinking about changing to non-runflats too.... after i run these to the ground....

houston_aggie

Hmm never even considered the bolt pattern, useful info. I went out to the garage and measured how much clearance is available between the top and trunk area when the top is stowed away. There's plenty of room underneath. I think up to a 10" wide tire would fit, but I concluded that 8" would be very safe. 6" would work no problem. The back latch of the top seemed to be one of the lowest points of interference, but you can flip it back to give you a little extra room.

The diameter of the OEM front tire/wheel combo is around 25" (18" rim), so that'll take up a majority of the trunk area. A 17" would take up a little less. You could probably place in one of the corners as neatly as possible to maximize trunk space, but this will probably make one of the storage boxes inaccessable. But if it were only to contain your jack, lug wrench, etc, then that would be fine since you'd be taking the tire out anway to get to them in the event of a flat. Centering it and placing it as far back as possible will work great too. One of the major obstacles I see is securing the spare down. If placement was in the corner, you could somehow put hooks in the sides and use a strap ratchet to secure it snugly. Gonna continue to think about this.

haljensen

Not a good idea. You would have to carry TWO spares, one w/front diameter and one w/rear diameter or the ECM will intervene and limit speed and RPM.

Different diameter on opposite sides of the rear will tear up the limited slip clutches.

Just having a tire pressure sensor showing a flat tire will trigger the ECM to reduce power and lock in A/H.

shopdog

You shouldn't be racing with a spare on the ground anyway, so no worries about AH bitching or the limited slip differential. Just drive slowly to the nearest tire repair shop, same as you would with a flat runflat.

houston_aggie

I thought about the different wheel diameters too... but I agree with shopdog, as long as you go slow you'll be fine, limited slip and all. There are a lot of cars that come with a donut spare, which is smaller in every way to a regular tire and wheel, and they don't have any problems as long as they limp safely to a tire repair shop.

overrev64

Forget about this whole spare thing all together. Why go through the hassle of finding a wheel that will fit front and back, securing it and the jack in the cargo area, dealing with the smell of the spare tire, etc. Just carry a plug kit and a small air compressor.

BTW, since the rear axles are rotating at different speeds, even at slow speeds, the limited slip differential clutches are constantly slipping producing heat and wear which would degrade its performance later on.
Also most space-saver spares are the same or very close to the same diameter as the tires on the car. They are however considerably narrower.

shurite44

Seems to me that some guys in the C5 section were using a GTO spare tire.

06C6Z

I currently run un-runflat tires...I got a tripple A membership...besides who want 60-70 lbs comming at you if you hit a wall?

shurite44

I am just getting ready to put my non run flat kit back together. I ran regular tires on my C5. But the run flats on my Z51 option are not bad really.

I have been driving my DR's to the track though and I am paranoid about a flat.

Here is my kit from memory anyway.

plug in compressor with light
four way with 19 mm
short scissor jack, I need another one of these by the way
plug kit
jacking puck
fix a flat, there are sensor safe brands by the way
cell phone and auto club of course
towel to kneel on
small bottle of well sealed soapy water to find hole
flash light that clips on my hat
needle nose pliers with wire cutter
I also always carry a small knife



I am going to throw this stuff in a little kit just for race nights.

I would recommend first trying to patch it on the car if you can. If not then the old fashioned way. Also the auto club may also be the best plan A.

Anyone that can add to this please do. We need a good kit list on the C6 for a flat. Lots of guys running non run flats now.

Also at this point I would like to add. If you ever find me dead along side the road, please take that silly flash light of my ball cap, thank you.

haljensen

"a lot of cars" cars don't have a clutch type limited slip differential, different speeds of left and right tires won't make much difference.

Between the different front and rear diameters, the 4 wheel anti-lock brakes and the Active Handling that depend on wheel speed inputs you are asking for trouble if you use an under or over sized tire.

houston_aggie

Much appreciate the input guys. Seems that a spare solution isn't gonna be as simple as I thought.