Tire change calibration
Thread Starter
Burning Brakes
Joined: Apr 2011
Posts: 1,149
Likes: 107
Tire change calibration
I have search but not very good returns. If I go to tires that are out of the factory size ratio how do you correct it? I have 18 inch wheels, front tire is 25.8 I want to go to 27.8 rears. I dont want TC issues. I do not have HP Tuners but I do have MDI 2.
Thanks Jim
Thanks Jim
Last edited by jimbob8915; Aug 17, 2025 at 10:18 AM.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
You can't change the programming in the EBCM. Even if you had the GM engineering tools to do that, you also need to know what in the H you are doing. It takes years of testing on many types of surfaces to determine the proper algorithms and calibrations. Just make sure you keep the ratio of rear/front tires close to 1.4 (vary by no more than a tenth). If you want a 27.8 figure out what diameter the front tire needs to be. I do this when selecting my 18-inch diameter front and rear track tires. It's pretty simple math.
Bill
Bill
