66L72

In the spring I bought a set of scrubs from a used tire supplier. Now I can't remember the name of the guy but I think it was something like GT Racing Tires or ? Very nice guy.
I asked for tires to fit OEM wheels on a stock C6Z for HPDE road racing type usage.
I finally picked up the rears yesterday and the sidewall is huge. I looked up the spec on the Continental website and it says they are good for 700lbs load. So they might not fit and if they do my car is too heavy?
The fronts are 285 645R/18
They all say Extreme Contact DR G5000 on sidewall.
Have I got drag racing tires?

I have been using Hoosier R6 up to now and obviously don't know a hell of a lot about competition tires. Might have looked at the wrong spec on the Conti website as well.

I think these tires came off a car #73 at the Sebring Race. must have a huge budget as they are marked set #7.

If anyone can tell me what I have and if they will fit it will be appreciated.

Thanks

Racingswh

Someone else may be able to give some insight regarding the compound but I ran those sizes on my Wife's GS with stock wheels. Fit and worked fine. She had the GTO compound IIRC which I don't think they have anymore.

They look and are super tall on the rear. Clearance was ok.

Bill Dearborn

Tires are about an inch larger in diameter than the stock tires. 27.9 inches Vs 26.7 for stock. Should fit, there should be enough room for an extra half inch of tire diameter. The size closest to the stock diameter is 685. Just divide the number by 25.4 to get the size in inches.

Bill

66L72

Thanks for replies.

Was your wife's GS lowered? Or did it ever get tracked with a lot of suspension deflection?

Even if they fit they are rated for 700 lbs. and what is that huge sidewall going to do to the handling vs the normal profiles?

I'm thinking I will be better off to get rid of these and get a more "normal" size.

GT Racing Tires

They will fit with no issues. We have numerous C6Z customers running this same set up.

Racingswh

Car was stock everything except for pads and fluid. Car was tracked. Handled fine. Tires had reasonable amounts of grip. Never had any issues.

66L72

Thanks Steve.

Also thanks Todd. Forgot you were a forum vendor.
I got a little spooked when I saw the size of the sidewalls.

For the record ....... Great vendor to deal with. Excellent purchase experience.

UrbanKnight

I run that tire on an 18" rim and love the look... No issues at all on my Zr1

0Anthony @ LGMotorsports

FYI.

ZR1 running a 300-650-18 front and 310-710-18 rear from our ALMS car...








Same setup on the ALMS car.....






My advice for running that tall of a tire, make sure your ride height is up enough or that tire will catch the rear inner fender liner.

66L72

Thanks Anthony. Using LG bars front and rear.

0Anthony @ LGMotorsports

Will depend on the track too...the car was fine at stock height with no passenger at the Glen...once he started giving rides we had to raise it or the tire would start to rub at the rear.

66L72

I am lowered to the max on stock bolts.
Does it make sense to remove the inner fender liners...run without.
I seldom use the car on the street.......mostly at mosport.

I know they are not expensive but not interested in experimenting and finding rub once I get to the track.

0Anthony @ LGMotorsports

Believe me....they will clearance the liner if you hit it..

rabrooks

I run that same size rear tire. It hits the plastic liners only once in a while. Once in a while means, when I actually got all I could get out of that corner. I went to urethane a-arm bushings and they don't hit as much now.

They have grip like crazy
It changes the final drive ratio enough that you can feel more bog on exit in certain corners. It makes you want to downshift one more gear coming into the corner where you weren't before.