calibrate speedo
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
DUB
Drifting
Joined: Jun 2013
Posts: 1,590
Likes: 60
From: ft myers FL/Munising MI
on the back hatch doors, the rpo code lists which speedo gear you have..At least that's what I remember when I went to the trouble to list them all.....plug in a gps...it''ll tell you how much you're off....
Team Owner
Joined: Sep 2003
Posts: 25,377
Likes: 2,735
Drive the car at 45MPH, 55MPH, 65MPH and 75MPH by the speedometer and record the speeds from a GPS for each of those speeds. We're trying to establish a consistent percentage error and then it's much easier to determine what's needed OR how one might want to correct the speedo/odo.
Post those numbers, the rear axle ratio of the car "as built" and "now" if you've changed it and mention what transmission is presently in the car. Is the transmission original? Rear tire size is what?
Post those numbers, the rear axle ratio of the car "as built" and "now" if you've changed it and mention what transmission is presently in the car. Is the transmission original? Rear tire size is what?
