Thread: Speedometer Recalibration

Results 1 to 12 of 12
  1. #1 Speedometer Recalibration 
    SE Level Member thenose's Avatar
    Join Date
    Apr 2012
    Location
    Athol, Massachusetts
    Posts
    115
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Hello all, I have a 2000 GTP I just picked up. The previous owner replaced the stock wheels with 17" ones and, obviously, the speedo is off. Seems to be a fairly consistent 5mph off, if I base it on my GPS's speed. Now, I am more than comfortable with simply subtracting 5mph from my speed when driving, but it is actually my wife's car and she will probably forget, a lot. Is there any effective way to recalibrate the speedo to make it more accurate?

    Thanks, I appreciate the help.
    Reply With Quote  
     

  2. #2 Re: Speedometer Recalibration 
    The Blue One blueguy's Avatar
    Join Date
    Jun 2008
    Location
    Dirtyzville, Missery
    Posts
    31,287
    Thanks (Received)
    1
    Likes (Received)
    2
    Dislikes (Received)
    0
    Get a tune, really.

    You'd need one.

    There is a tire size table that will change it.
    Sold WBody's: '03 Blue GTP/'98 Green GTP/'98 Silver GT/'05 GXP
    '99 Chevrolet Silverado Classic Z71 4x4 - K&N Intake/Gibson Exhaust #TRUCKTHINGS
    '12 Buick Regal Turbo - ZZP CAI/20% Tint/HID's
    '89 Ford Mustang LX Notchback - LM7 5.3, 4L80, 9", HX40
    '04 Chevrolet Corvette MRM A4/LS1 - TSP LT's, 3"O/R X, AFE S2 CAI
    Reply With Quote  
     

  3. #3 Re: Speedometer Recalibration 
    GrandPrix Junkie jteske88's Avatar
    Join Date
    Mar 2011
    Location
    Yoga city
    Posts
    4,195
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    uhm get your gps and just move the needle
    Reply With Quote  
     

  4. #4 Re: Speedometer Recalibration 
    SE Level Member thenose's Avatar
    Join Date
    Apr 2012
    Location
    Athol, Massachusetts
    Posts
    115
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Thanks guys. By "tune" I assume you mean a tuner?

    Can't just move the needle, wouldn't fix the HUD.

    Thanks again
    Reply With Quote  
     

  5. #5 Re: Speedometer Recalibration 
    The Blue One blueguy's Avatar
    Join Date
    Jun 2008
    Location
    Dirtyzville, Missery
    Posts
    31,287
    Thanks (Received)
    1
    Likes (Received)
    2
    Dislikes (Received)
    0
    Yup, moving the needle wouldn't do anything.

    I'm sure there are plenty of people in the New England Area that would hook your car up and re-adjust it for you, and hell, maybe even tune it for those MPG's
    Sold WBody's: '03 Blue GTP/'98 Green GTP/'98 Silver GT/'05 GXP
    '99 Chevrolet Silverado Classic Z71 4x4 - K&N Intake/Gibson Exhaust #TRUCKTHINGS
    '12 Buick Regal Turbo - ZZP CAI/20% Tint/HID's
    '89 Ford Mustang LX Notchback - LM7 5.3, 4L80, 9", HX40
    '04 Chevrolet Corvette MRM A4/LS1 - TSP LT's, 3"O/R X, AFE S2 CAI
    Reply With Quote  
     

  6. #6 Re: Speedometer Recalibration 
    GrandPrix Junkie jteske88's Avatar
    Join Date
    Mar 2011
    Location
    Yoga city
    Posts
    4,195
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    didnt know you had a hud
    Reply With Quote  
     

  7. #7 Re: Speedometer Recalibration 
    SE Level Member
    Join Date
    Oct 2010
    Location
    Saratoga NY
    Posts
    94
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Use this to determine how far off the car is. Tire size calculator

    A tuner wont have a "table" but you will be able to correct the 3% it may be off. It wont just affect the speedo it can change shift points tcc lockup ect ect if the tires are that far off.
    98-XP e85 SSAC HPT AGX Bullets Every BRM piece home built trans
    99-HPT ssic headers ported blower
    94z28 with a cam that chops so hard it hurts def peopels ears.
    Reply With Quote  
     

  8. #8 Re: Speedometer Recalibration 
    SE Level Member thenose's Avatar
    Join Date
    Apr 2012
    Location
    Athol, Massachusetts
    Posts
    115
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Looks like I'm off by 6.2%, based on the calculator.

    Thanks again everyone
    Reply With Quote  
     

  9. #9 Re: Speedometer Recalibration 
    SE Level Member thenose's Avatar
    Join Date
    Apr 2012
    Location
    Athol, Massachusetts
    Posts
    115
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by Jteske88 View Post
    didnt know you had a hud
    Sorry, wasn't trying to be snarky there (I usually am, I just wasn't TRYING that time).
    Reply With Quote  
     

  10. #10 Re: Speedometer Recalibration 
    DUI BABY Bio248's Avatar
    Join Date
    Jan 2008
    Location
    MILWAUKEE
    Posts
    31,340
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    just leave the speedo off and remember how far off it is.

    if you ever get a chance to put stock wheels back on, or the right diameter tires, you wouldnt want to have to readjust again. you're wasting time doing it the first time.
    Reply With Quote  
     

  11. #11  
    Awaiting Confirmation
    Join Date
    Jul 2009
    Location
    aowdnawi
    Posts
    23,292
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    You have you have to change the tire size in the bcm as well which can only be done with a tech2.

    Also note theoretical diameter is not what the pcm/bcm use for tire calcs either.
    Reply With Quote  
     

  12. #12 Re: Speedometer Recalibration 
    SE Level Member thenose's Avatar
    Join Date
    Apr 2012
    Location
    Athol, Massachusetts
    Posts
    115
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by gmpowered View Post
    Use this to determine how far off the car is. Tire size calculator

    A tuner wont have a "table" but you will be able to correct the 3% it may be off. It wont just affect the speedo it can change shift points tcc lockup ect ect if the tires are that far off.
    Other than the wife forgetting about the speed difference, I was also worried about this. I mean, if the computer bases things off the speed and the speed is wrong....

    Now I just need to find someone to help with tuning. Having never done this before, what is the typical procedure? Is this a bring it to a shop sort of thing or find someone who likes beer and knows what they are doing?

    Thanks
    Reply With Quote  
     

Similar Threads

  1. Speedometer help
    By ElAlacran2010 in forum 3.8L V6 Supercharged (L67)(L32)
    Replies: 0
    Last Post: 06-04-2011, 10:55 PM
  2. 99 GTP speedometer
    By cfallsguy in forum Audio, Security & Visual Electronics
    Replies: 0
    Last Post: 07-31-2010, 10:57 PM
  3. Speedometer ??
    By 04BlackComp_G in forum General Tech Discussion
    Replies: 0
    Last Post: 04-17-2009, 10:53 PM
  4. speedometer
    By digilue in forum General Tech Discussion
    Replies: 2
    Last Post: 12-28-2008, 07:10 AM
  5. Speedometer Problem
    By GTPOWER in forum General Tech Discussion
    Replies: 8
    Last Post: 07-23-2008, 12:33 AM
Tags for this Thread

View Tag Cloud

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •