Tires

[VetteMed]

Originally Posted by Kevin

if you go to 335's in the rear wouldn't you want to go with 285's up front to keep the ratios correct?

Do you have a 4 wheel drive ZR-1? What ratio are you referring to?

[Kevin]

Originally Posted by VetteMed

Do you have a 4 wheel drive ZR-1? What ratio are you referring to?

a 4wd twin turbo zr-1 would be awesome. PETE, get on it. I would assume that if you go up in size on the rear you should go up in size on the fronts to keep the handling consistent with what it was

[VetteMed]

Originally Posted by Kevin

a 4wd twin turbo zr-1 would be awesome. PETE, get on it. I would assume that if you go up in size on the rear you should go up in size on the fronts to keep the handling consistent with what it was

Hmm, could be right, I'll defer to someone more knowledgeable than me.

[Jagdpanzer]

Originally Posted by Kevin

if you go to 335's in the rear wouldn't you want to go with 285's up front to keep the ratios correct?

The difference in circumference is only 1.2% between 275/40-R17 and 285/40-R17 size tires. I ran both 275 and 285 fronts with 335/35-R17 rears and did not experience any unusual handling.

[Kevin]

Originally Posted by Jagdpanzer

The difference in circumference is only 1.2% between 275/40-R17 and 285/40-R17 size tires. I ran both 275 and 285 fronts with 335/35-R17 rears and did not experience any unusual handling.

good to know

[RHanselman]

Originally Posted by VetteMed

Do you have a 4 wheel drive ZR-1? What ratio are you referring to?

I think I remember hearing that if the ratio is off too much it would mess with the ABS...

[Jagdpanzer]

If the wheel revolution difference between the front and rear is greater than around 4% it will eventually trip the ABS and ASR (if you have it) alarm lights on the dash panel. I experienced this when switching to 345/30-ZR19 rear tires which created a 5.2% speed difference. Fixed it by replacing the stock 47 tooth ABS reluctor wheels on the rear spindles with 50 tooth reluctor wheels I machined up.

[secondchance]

Originally Posted by Jagdpanzer

Fixed it by replacing the stock 47 tooth ABS reluctor wheels on the rear spindles with 50 tooth reluctor wheels I machined up.

Dr. Phil,
You make it sound soooo e-easy...

[mike100]

Originally Posted by Jagdpanzer

If the wheel revolution difference between the front and rear is greater than around 4% it will eventually trip the ABS and ASR (if you have it) alarm lights on the dash panel. I experienced this when switching to 345/30-ZR19 rear tires which created a 5.2% speed difference. Fixed it by replacing the stock 47 tooth ABS reluctor wheels on the rear spindles with 50 tooth reluctor wheels I machined up.

Maybe this is why my 91 gets an erroneous ABS signal on the DIC sometimes driving down the roadway at 40 mph (not on brakes). It hasn't happened much recently, but more often when the rear tires were at new diameter.

I never had this problem on my 95 LT1 car, I bet they changed up the tolerances some to prevent false fault conditions on the later system (95/96).

[HAWAIIZR-1]

With all my lifetime with cars and trucks if I ever bought larger diameter wheels, i.e. plus 1 or plus 2, etc. I have always been able to keep the overall diameter the same as when I went to CCW 18" I found tires that were the same or most close to OEM overall diameter factory tire.

Is this not possible when going to 19" (plus 2)? Even when I put 20" wheels in my Honda Ridgeline from 17" I was able to keep the overall diameter so no affect on ratios.

I have not checked, but just curious to see all this about the diameter and change of ratio so curious?

Thanks,

Craig