C5 Active Handling / Tire Sizes

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Oct 20, 2011 | 06:12 PM

WICKEDFRC

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From: Arizona

C5 Active Handling / Tire Sizes

I have tried the search feature and can not locate the margin of error from front/rear tire height differences that effect active handling.

What is that margin of error before one would start seeing active handling issues?

The difference between the NT05R front 285/18 to rear 315/18 is 1.46".

Is this a safe match?

Thanks in advance.

Oct 20, 2011 | 06:24 PM

Blue 92

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From: Columbus Ohio

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St. Jude Donor '06-'08-'10

Most say about 1/2" as a minimum to avoid throwing codes.

That about what I have with 295/35x18 and 275/40x17 and haven't had any issues.

Oct 20, 2011 | 08:15 PM

johnpowe

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From: Gun Barrel City TX

Try this thread

http://forums.corvetteforum.com/c5-g...ah-issues.html

great explanation about wheel/tire size in relationship to AH/TC

Oct 20, 2011 | 09:24 PM

LV,99LS1VERT

Racer

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From: Las Vegas Nv

I am running 315/25/19 rears and 295/30/18 fronts no problems with active handling codes.I did have a AH code once but it was cause I had a rear tire going down on the freeway..I must say it corners like a beast,I can dive deep in turns.I also have a 2 inch lowering kit C6 Z06 Sway bars and new RTD shocks.

Oct 20, 2011 | 09:51 PM

WICKEDFRC

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From: Arizona

All, this is great info, but does anyone have a bonafide answer such as "Not more than .50 (half) an inch? One inch, etc.

I will check that link.....

Oct 21, 2011 | 04:17 PM

Blue 92

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From: Columbus Ohio

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St. Jude Donor '06-'08-'10

Quote:

Originally Posted by WICKEDFRC

All, this is great info, but does anyone have a bonafide answer such as "Not more than .50 (half) an inch? One inch, etc.

I will check that link.....

It's seems that most folks go with the rears approaching the same diameter as the fronts.

Looks like you are trying to find out of there is a maximum limit where the rears are X" larger and could cause an issue, correct?

Interesting question as to whether or not AH would activate if the rear wheels were turning X% slower than the fronts.

Did a quick Google search there didn't seem to be a definitive answer.

Oct 22, 2011 | 11:21 PM

Bill Dearborn

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From: Charlotte, NC (formerly Endicott, NY)

Active handling isn't affected by the tire size. Traction Control is affected by it. AH is initiated by the EBCM based on a computation of the inputs from the steering, yaw and lateral G sensors. Some people can run equal diameter tires front and rear and not have any TC issues. Others can't do it. I could run 25.3 inch diameter tires front and rear with no TC issues on my C5Z.

Bill

Oct 23, 2011 | 06:10 AM

CJW

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Hi I had an issue where the traction control kept cutting power at 65mph tried everything electrical including EBTCM along time later I rechecked tyre sizes and found I had 265/40/18 not 265/40/17 (fitted before I bought the car). There are several websites that will calculate mph if you put in tyre sizes compare the difference at various speeds(difference increases as speed increases) then check at which speed the traction control cuts in ( I think it's about 3/5mph) check each combination but it's about 1" bigger on the back.

Colvin