titanle

Has anyone run a 11" in the front of their C3? I went through a bunch of wheel threads but couldn't find any info on this. I'm narrowing down my wheel selection to 3 ( LT III, Rocket Attack or possibly AR 407). The 407 is available in 18x11 and I am able to choose what offset I would prefer. I have the L88 flares on my 68 which would accommodate these wheels I think.

If 11's are feasible for the fronts, is there a desired backspace?

Thanks

69autoXr

I run 17x11" LTIII on the front of my '69 with L88 flares. Backspace is 4.5"

Rears I have 17x11 with 3.875" backspace, and 18x12 with 4.5" BS

titanle

How much caliper clearance did you go with? I just spoke with the rep for the AR 407 and he said max clearance for brakes is 1". Also what size tires are you running?

69autoXr

For the 17's they don't offer options for caliper clearance, but it is adequate. For the 18x12's I went with the LP; tried them on the front for caliper clearance and they were fine. I'll order 18x11 fronts at some point with 4.5" BS and LP.

Tires on the 17's are 315/315 or 315/335, on the 18x12's they are 335.

titanle

Do you have any other mods that would impact the wheel sizing/backspacing?

We both the have the same L88 flares so I'm wondering if I could get away with 18x11 with 4.5 BS for both the fronts and the rears

69autoXr

Front has bump steer blocks which probably reduce the maximum front backspace I could use, 4.5" still gives plenty of clearance. In the rear, I have a VBP composite leaf, standard width, and the parking brake brackets on the trailing arms are gone. I also have a 9/16" rear sway bar which does not interfere with the 4.5" BS wheels.

If you go 11's in the rear I'd go with backspace closer to 4" for the rears.

titanle

I will confirm with the rep if they can make me a set that is 18X11 with 4.5" BS front and 4" BS rear. I'll be using Falken Azenis 295/40/18. If I recall correctly, my car doesn't have a rear sway bar and the trailing arms are stock. Do you experience and interference or rubbing in the front? Whether it be on the frame or on the flare itself?

69autoXr

No rubbing, except maybe on my brake ducts. That 295/40-18 is over 1.5" taller than my 315/35-17's though...

titanle

That's a fairly big difference, I feel like that should affect the rears but may possibly result in rubbing on the front?

69autoXr

It might

ignatz

Just curious as to where you think the point of diminishing returns is with regard to width?

69autoXr

>315

Metalhead140

I actually have better clearance for backspace on 17" wheels since fitting the VBP bumpsteer blocks. I previously had to have small spacers (0.2") fitted to clear my 17x9.5 wheels with 5.05" backspace on the front, with the bumpsteer blocks fitted I don't need the spacers.

69autoXr

Maybe I'm thinking back to my 16" days...

Thanks!

titanle

Looks like i'll be selling my current tires and going a different route. Seems like going with 17x11 LT III wheels with 4.5 BS front and 4 BS rear with 315 35 17 all around makes more sense and less chances of rubbing and interference.

User-C3

I'm also running 17x11 on the front, 5" backspace with L88 flares. I would prefer they filled the flare a bit more so a 4.5 backspace as stated previously by 69autoXR would be a better fit. my rears are 17x14 also with 5" backspace. I have full vbp suspension with composite springs. rear spring needed to be rounded a bit to clear the wheels with the 5" backspace. an 18" wheel would be fine. If I bought new wheels for mine, I would go 18x13 rear with 5" backspace, and 18x11 front with 4.5 backspace or maybe even 18x12 with 5" backspace. If your car sees mostly track time like mine does more contact patch the better.

gkull

Wheels with very little BS compared to width have very little strength and durability. Bearing loads go way up.

When you win a championship in your area SCCA and of course buying all your Hoosier R1s slicks from tire rack gets you a season of sponsorship

I was always able to run consistent laps. So any changes would show up in the lap times during testing. I actually settled in on 295 R1s over 315s

it really does come down to how the car is setup. My car is heavier in the rear, 700 pound front springs, and big GT1 brake calipers. You don't see miatas with 315s. You need a certain amount of weight per contact patch square inch. If you have everything right and your car is pushing then I would increase the front tire width to increase traction

stock brakes even with 600 degree fluid will only last a lap or two with wide slicks

even 550 front springs become a problem with increased front traction. Both in body roll and front end dive when braking.

Why do you want the same size tires all the way around?

titanle

im doing it purely for looks. I will never race/track my car, its just going to be a summer cruiser with some spirited driving from time to time.

Strokemyaxe

gkull

the short answer is. All years of corvette brakes will fail within a few laps on a fast track.


as tire traction increases your cornering exit speed increases. So you are going faster into the braking zone. You are putting higher loading on the very marginal stock vette brakes. Even 600 degree fluid will boil and result in complete brake failure. Slicks just make it happen sooner than street tires

over the winter break I decided to get a lot more serious about being competitve against the the trailer queen dedicated racing cars. I bought 295 /17 front and 345/18 rears first points road race of the season I go out and do a 75 % lap to get some heat into my brand new slicks and then I go for it. Before I could complete 2 hot laps I had complete brake failure.

I later became a driving instructor and I would only work with fast cars.

So people would show up for the classes with brand new vettes None of them other than the rare C6 ZR1 ever had brakes good enough to last a full 20 or 30 minutes on the track. Every vette no matter what the year first fills the interior with burnt brake pads smell and you have to slow down and go easy on the brakes to complete a session