NYOverlord

Does anyone know the minimum and maximum overall tire diameter for a C6Z?

I bought 18x12 rear wheels and looking for drag radials. I don't want the tires to rub the inner fender liner when it squats or goes over bumps.

Nino S

I run a 345/35/18 drag radial on my 18x13 and they are perfect. 28" tall so gearing is great with big power, 170+ mph at 7000 rpms in 4th gear and only rub if it is strapped down too much on the dyno. Mickey Thompson and M&H both make the size and hook great for a 18" rear.

Spoolin8

I run an 18x12 wheel and have a widebody conversion. Running M&H racemasters in 345/35 which comes out to around 27.7" Im also pretty slammed on bilstein suspension, can fit a finger between the wheel well and tire. Doesnt rub under 750hp accelerations. I would think you would be fine with the same size, especially if you're not lowered.

Unreal

There is no set number. Depends on how low or high you make the car. What shocks, what springs, road conditions, etc.

If it does rub every once and awhile, who cares? Fender liners are cheap.

Unreal

There is no set number. Depends on how low or high you make the car. What shocks, what springs, road conditions, etc.

If it does rub every once and awhile, who cares? Fender liners are cheap.

old motorhead

Thanksgiving around here.....

CI GS

neverstop

17" ET steet R 305 size and zero rubbing unless hit a big dip at speed, despite car being super low, could easily put something bigger, no idea what the max is though

BIGMAC

I am led to believe a 28" rear tire when paired with the stock front will create a rear to front diameter ratio that is out of the tolerance allowed by the Active Handling / Traction Control System and could cause big problems including unwanted intervention of the AH/TC system and/or the car being put into limp mode. Comments?

BIGMAC

schpenxel

The ratio of front to rear is what matters active handling/ABS/TCS wise

BIGMAC

Understood. I will edit my post to make that clear.

Unreal

I run 28" rears and never had an issue, but do rub on bumps.

Like I said, it all depends on the overall setup. You can rub a 26" or never rub a 29". Depends on how low, and how stiff the suspension is, and how you use the car.

BIGMAC

What is your number for the max ratio allowed? The one I have seen most often quoted is 1.04.

BIGMAC

schpenxel

Heck if I know

grocerygetter

It's around an inch...some cars are pickier than others. I run a 1 inch stagger on street wheels and my track wheels are 26" front and back. No issues either way.

CI GS

I see guys on here that are running 28" M&H rears (which are actually ~27.5") with ~26" fronts, and they claim to have no problems with AH. Sounds like it's hit and miss. Perhaps those that don't experience any issues are running with AH/TC disabled?
I'm about to find out myself...

BIGMAC

I see that as well. I want to run the M&H 26" / 28" skinnies / DR's on Weld S71 wheels but the "hit and miss" relative to AH issues has me freaked out. I have hesitated to gamble on spending the big $$$ for this package only to find out this is a "miss" on my 2012 GS. I have been trying to obtain information for over a year without success to increase the odds of a "hit" to better than 50/50.

Unreal

I run a 26/28" combo.

It depends on what you mean by miss. I get some active braking warning slowing down some times, but it doesn't mess or do anything bad. If that bothers you, don't do it.

NYOverlord

"Slowing down"? What do you mean by slowing down?




I am trying to decide between Mickey Thompson E/T R, Mickey Thompson E/T SS, and M&H Racemasters.

Which one would you guys recommend for roll races from 55 mph-180 mph?

Basically 1/2 mile events at airports (SlipStream in PA).

NYOverlord

Do you only run 1/4 mile at the drag strip with those tires, or do you also run 1/2 mile roll races?

And what's the highest speed you've taken those drag radials to?