Results 1 to 5 of 5

Thread: How do you calibrate the speedo for different tire size in 3.6

  1. #1
    Tuner in Training
    Join Date
    Feb 2010
    Posts
    16

    How do you calibrate the speedo for different tire size in 3.6

    Can someone explain how do you calibrate the speedo for different tire sizes in HPT 3.6?

    Thank you
    Christian

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,565
    Different as in front to rear?

    Or just different tire size from factory.

    I do not believe there is any way to set a front tire size and a rear tire size seperate. When GM did factory rim size differences, the front and rear tire had tire sizes that came with the small window of like 1-3% difference so the ABS didn't freak out and cause it to engage all the time.

    If you are just needing to change the tire size like normal you'd just go under the gear tire wizard in the edit tab. If that didn't work you could manual input the revs/miles stuff under the speedo tab to get your speedo corrected.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Tuner in Training
    Join Date
    May 2017
    Location
    Sacramento California
    Posts
    11
    Hi and thanks for the reply.

    It is to change the rear tire size. And I did change trans and diff in my c5 corvette to one out of a c6 but the diff gear ratio is the same 3:42 as what was in it, just the trans gearing is different.
    I don't have my laptop with me so I'm trying to remember but in HPT 3.6 under speedo it says the "gear ratio" 3:42 which is correct
    and it doesn't ask for the tire size or diameter but instead it asked I think revolutions per mile, I think that is what it said.
    Have you seen that?

    Thank you,
    Christian

  4. #4
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,565
    Use the gear tire wizard in the edit tab, the tire size can be found there.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
    Potential Tuner
    Join Date
    Oct 2014
    Posts
    1
    Just used the gear tire wizard, it worked like a charm! I switched from 4.10 to 3.42s.... All you have to know is your tire diameter and final drive ratio.