fleming23

I don't know if this technically classifies as "tech" but is somewhat technical in nature. If mods want to move to general, so be it.

After watching RideTech build their 48 hour car and asking countless questions on the forums, and to Bret in private messages, I could not believe there were not more cars running 10" or wider wheels on all 4 corners. Having just taken this car to the track, it was really suffering from front bite and a wider wheel would have been ideal to get some more corner exit speed.

I guess the good news is, my Chevelle has 18x10 with a 5.75" backspace and a 295/35 tire on the rear which I "borrowed" for some test fitting tonight. The Chevelle has a staggered 18x9, 18x10 set up so I only stole the rear wheels and put them on the passenger side of the Corvette. I did have to remove the rear sway bar, but have read many accounts that the cars actually handle track work better without it anyway. I won't say it does not rub at full lock, because a 255/50 rubbed, but it does clear everything and still allow for a very tight turning radius. Damn....now I have to do some wheel shopping and I already know I don't have cheap tastes....I have a feeling a call to Forgeline will be happening this week.

Shark Racer

I'm hoping to run a 285/40-18 on the back of mine, so this is good news indeed.

Which trailing arms are you running?

fleming23

I have VTech offset trailing arms, but I am not sure that it would matter with an 18" wheel, or so I have heard.... Never tried it before I replaced them to know for sure though.

7t9l82

69427

I'm running C5Z06 wheels for track days (18x10.5 rear, and 17x9.5 front) with 285/35-18 tires in the rear. Just for kicks the other day I tried the 18" wheels/tires (with 2.25" adapters) on the front. They fit, but there's just a touch of sidewall rubbing on the inner fender well where there's a bulge above the A-arm opening.

Kid Vette

Forgeline?! Get you wallet out!

TheSkunkWorks

These fitments being atypically large for a C3 without flares, I'm sure that inquiring minds such as mine would want to know...

How close to the frame above the TAs are your rear tires?

How much front wheel and tire clearance at the upper CA ***** and outer tie rod ends?

Clearances checked throughout range of suspension travel?

Chassis and/or suspension mods?

More pics?

And, just to make certain, the 295 isn't a typo???

TIA for filling us in with the entire story.

terrys6t8roadster

I'm running 18x11 with 5.5b/s. VB&P offset trailing arms. Tire size is 305/660-18, with rear bar intact. Fronts are 18x9.5 with 4.25 b/s, steeroids R&P. Fiske wheels, the rears stick outside the body lines as 6t8s don't have any wheel flairs about 1.125". T

fleming23

I already pulled the wheels back off last night as I wasn't going to ride around with a 17 on one side of the car and an 18 on the other. I will take a wheel off and try to get some suspension photos for clearance purposes but it won't be today. The 295 was certainly not a typo.

My car is not "stock" in that is has VB&P Performance Plus suspension both front and rear. Other than the offset trailing arms everything else is factory location.

I haven't tried but based on initial inspection I think a 305-315 tire is possible. Please note, this absolutely does rub on something up front (either sway bar or frame, didn't crawl under and look too closely as it was getting dark) when turning at full lock. It isn't bad and is easy enough to manage by just not cranking the steering wheel as far as it will go. I was easily able to turn around in a cul-de-sac with no rub so it works for me, others may complain about it not working 100% perfectly.

fleming23

Also, when I drove it back to the house, I pushed it a bit on a deserted road that has a decent dip. Wanted to see if the suspension travel would cause any rubbing, but I did not hear anything. This was obviously not a very technical test. I'll update the thread as soon as I get bored enough to swap out the wheels again.

3JsVette

I'm guessing it's rubbing on the frame. The 18" wheel allows for a lot of room for suspension components to fit inside the hoop of the wheel. The 5.75" backspace may be a bit too much.
Besides if there's not a little bit of rubbing then the tires aren't big enough.

roscobbc

I have 285/40/18's on 9" wide rim with 5" back space on the rear end of my '68. Tyre fits inside wheel arch with full travel. Using stock trailing arms. I measured 1/4" to 3/8" clearance between sidewall and frame, yet frame is 'polished' ! - I presuming that 'energetic' cornering causes trailing arm to flex (causing the 'polishing') - oddly tyre is unmarked!
http://i160.photobucket.com/albums/t...c/DSCF1018.jpg

Rebelrob

2nd that. I have 285 with 9.5 inch wheel , stock T/A's.
Looks good Fleming.
The Ridetech 48 hr Vette has 315's if I remember correctly. The rears did stick out past the fenders a bit. But I am sure the updated suspension kept the tire from hitting the fender lip.

Gale Banks 80'

For what ever it is worth I have run 315's on my 80 for a number of Years now. (17") with Frame polishing on the inside and the Tire somewhat outside the Fender on the outside. I have since Flared the Fender 1/1/4" to get things back underneath. Going with the rule of if something isn't rubbing there isn't enough Tire I'm in the process of narrowing the Frame at the Polish points and have the bigger is better attitude yet again. So far I have had this attitude a number of times, stock 235 then 255, then 275 then 315 and now ??? Craigslist even supplied a very used 345 19 ( Viper) Tire for eye balling.

glackore

Looks great Fleming!!!!! Yes, you can push the limit on the wheel/tire combo. I may put an 18x9.5 on the front of mine at some point. That is what is on the back, I'd just run a different tire on the front. Wifey won't understand another $1,500 for 2 wheels and 2 tires right now.

DucatiDon

Slight tangent here, but what headers do you have that are hanging down so very low beneath the car???

fleming23

If I had to guess....Hookers.

fleming23

Hey, I understand! I have the same wheels you do (only 17x8s all around) and am struggling with the decision to ditch them entirely to buy something new.

FLYNAVY30

Hey fleming, sharp car! Interesting I just saw this post as I was talking to the Ride Tech guys about this very subject. I am going to bolt on their stage 2 set up with a front sway bar and plan on running 295/40/18s on 18x10.5 with 5.5 back spacing at all 4 corners. I was concerned that while the 295/40 is about 8/10s narrower than the 315/30 they are running, its almost 2 inches taller at 27.2 inches. They said I shouldn't have an issue with clearance....I want to run a slightly thicker side wall because of the crappy roads in the area and the taller (relative to the Ride Tech car) combo will allow me to lower the car to get rid of the fender gap while still maintaining a useable ride height.

roscobbc

Yep - Supercomps - and, yes speed-bumps and on-ramps are a 'challenge'