Instruction for use of Speedo Spread Sheet

This Excel Spread sheet will work out everything you need to get the correct speedo calibration for your kit car. Just print it out hand it to your speedo repairer and they can calibrate the speedo head to suit your drive line, it may also help ease the passage of the car through the UK SVA test.


You will need the follow data

(1) Tyre size
(2) Diff ratio
(3) Speedo drive ratio
(4) TPM of Speedo head you intend to fit.

The example figures are for a Escort 3.88 diff, Sierra gearbox and 185/65x14 tyres, the speedo head is from a Triumph Spitfire.

Data is entered in the blue cells.
All calculation cells are yellow and are protected.

If you want to alter the sheet the cell password is XWG684  (the registration number of an Austin Champ I once owned :))


Andy