C5z_Dennis

Any of you guys running a 28" tall tire on 17's. I'm going to be tracking the car a lot and I want to run a bias ply but I dont know if it's going to kill the gearing. Car makes 458rwhp and I plan on running a 150 shot this year for gap insurance

robz

I'd run a 26" tire.
If you spray alot you can get away with the 28".
You should do a gear/rpm calculations and know exactly where you would be going thru the traps for a particular mph and that will give you insight on what to use.
You want to be going thru the traps several hundred rpms over peak hp if possible.
Shift points are critical too.

C5z_Dennis

I thinking I'm going to have to run a 26" radial but I wanted a bias ply to prolong the life of my drivetrain lol

robz

Don't go too wide.

C5z_Dennis

Probably going to get a 275/40 r17 et street type r

Big Vig

I run a 28x11.5x16 bias ply on my C5. I'm just shy of 600 rwhp NA with stock 3.42s.

robz

Think I'd rather see you with 26"s too.

C5z_Dennis

Going to try the type r's. I'm probably going to switch to a 15 later on down the road

robz

That's cool. Then I'd consider a short and narrow slick.

I ran a 26x8.5x15 stiff wall Hoosier slick in my cam only c5Z setup with good success on a 10.5" rim and the diameter was close to 25" adding to the gearing.