will gears affect the speedometer calibration on an M6? It just seems that since getting my gears the car is ALOT faster, but it never feels like im going as fast as my speedometer says.... maybe its my mind playing tricks on me or soemthing since i drive my truck all the time... do they effect it? This is with stock wheels by the way

 

Yes! You have to have the speedo recalibrated.

 

Yes you have to recalibrate your speedo. To check how far it is off
use a gps. Shops in my area want 300 hun and the car for two days.
I found a shop in wash. or oreg. they will sell you a recalibrator for 160.
you just have to install it. (253)582-3890 speak w/eddie.

 

yes it is off.

what gears did u go to. 4.11's

 

3.73's

 

Your speedo is indicating a speed 9% higher than your actual speed. For example, at a true 70MPH, your speedo is indicating 76MPH. The odometer is also racking up 9% extra miles. Drive it 1,000 actual miles, and you will add 1,090 miles to the odo.

You need to have the PCM reprogrammed for the gear ratio. You can get a "cheapie" version of LT1_Edit that would allow you to make the correction with a laptop, or you could find a used Hypertech programmer (make sure the original owner returned his PCM to "Stock" or it won't work on your car), or there are people like MadZ28 and PCMforless that will reprogram it for you.