Guys, I have a question about the traction control system.
I know that to make it work properly the rear tires have to be bigger.
If I was to install the same size tires and wheels on all four corners what would I have to do to make this work?
HELP

 

I think that some on this forum actually run same size tires front and rear for track use...but I don't know if they actually use traction control for those track days.

 

I read this on another forum. This may answer your question.

It was on the Vette Barn Forum

Guys:

I have been seeing a bunch of posts recently with folks asking questions about what sized tires to go with there rims. They are also asking if there Active Handling, and Traction control will have issues.

First off, I would like to say that your Rim size has NOTHING to do with the stagger that GM built into these cars. You do not have to upgrade to a 18/19 combo, or 19/20 combo. You can upgrade to 18/18 or a 19/19 combo with no issues. The TIRE sizes is what maintains the built in stagger from GM. As long as you choose the correct tire size then you will NOT have issues with Traction control or Active Handling.

Check out this great little wheel/tire calculator I have been using for years.
Wheel / tire size calculator / comparer - RIMS-N-TIRES

If you input the original tire you have now, and input the proposed size you want to go with, it will output the differences.

**************************************** ********** **************************************** ***

Here is an example of the Calculator output comparing a stock sized rear Z06 tire to a larger tire size (the size I upgraded to in my rear).

Tires:.................Tire 1..................Tire 2
Tire size..............295/35-18...........305/30-19
Section width.......295 mm (11.6'')....305 mm (12'')
Sidewall..............103 mm (4.1'').......92 mm (3.6'')
Tire diameter.......663 mm (26.1'')......667 mm (26.3'')
Rim sizes.............18x9 to 18x11.......19x9.5 to 19x11.5
Circumference......2082 mm (82'').......2094 mm (82.4'')
Revs per mile........773.....................768. 4
Speedometer: Assuming that this is OEM tire and speedometer readings are correct.When speedometer reads 60mph (96.6km/h) actual speed will be 60.4mph (97.2km/h): 0.7% faster.

**************************************** ********** **************************************** ***

Stock C5 Tire Sizes, and Stock C5 Z06 to use in calculator:

Using the original size of your tires (see below). Use the above calculator and do the math. If you up size your tires, you want to make sure you up size the front and rear the same amount (or as close as possible). That way you avoid the computer seeing a mismatch in tire speed between the front and rear tires. Thus eliminating Active handling, and Traction control issues.

Stock C5 (97-04):
Front
Rim size = 17x8.5" rim
Tire Size = 245/45/17
Circumference = 2047mm
Diameter = 652mm
Rear
Rim Size = 18x9.5"
Tire Size = 275/40/18
Circumference = 2126mm
Diameter = 677mm

Stock C5 Z06 (01-04):
Front
Rim size = 17x9.5" rim
Tire Size = 265/40/17
Circumference = 2022mm
Diameter - 644mm
Rear
Rim Size = 18x10.5"
Tire Size = 295/35/18
Circumference = 2082mm
Diameter - 663mm

**************************************** ********** **************************************** ***

Here is an example of what I did when I upgraded to a 19/19 combo.
I have had no issues with traction control, or active handling since I got this combo.

Using the calculator above I calculated up sizing my front and rear tires to a size that kept me very close to my stock tire circumference/diameter, AND made sure that both tires increased/decreased the same amount.

Front
Stock Z06 = 265/40/17 = (Circumference = 2022mm)(Diameter 644mm)
Proposed = 275/30/19 = (Circumference = 2038mm)(Diameter 649mm)

Rear
Stock Z06 = 295/35/18 = (Circumference = 2082mm)(Diameter 663mm)
Proposed = 305/30/19 = (Circumference = 2094mm)(Diameter 667mm)

So with my proposed new tire setup:
Front --> Increased the Circumference by only 16mm (Diameter 5mm)
Rear --> Increased the Circumference by only 12mm (Diameter 4mm)

As you can see above (for my situation), both proposed tires are barely larger than my stock Z06 setup. The most important thing is that they both increased the same amount (ish). Thats the key to keep the traction control, and active handling in check.

 

That is a great amount of info, Thanks
I see that a small difference from front to back keeps the active handling working. Thanks again

 

I have 18 all around , got new wheels and only 2 new tires, moved old rears to front and they are a tad bigger so I just turn the TC off , I will replace the fronts if they ever wear out, the back, they are pretty much slick now and will have to be replaced soon after I get it back from the shop , Necessary Evil (Englandgreen)