5 replies to this topic

[blacktulip]

where and how much am i looking at to change the calibration on a centre speedo 3.44 ratio to 3.1. has anyone done this before?

[icklemini]

where and how much am i looking at to change the calibration on a centre speedo 3.44 ratio to 3.1. has anyone done this before?

'Speedy Cables' can recalibrate your speedo head... about £60 notes

costs about the same (and is generally more accurate) than buying the drive gears for fitment in the box....

TTFN,
Dave

[jack_marshall]

Thats bloody expensive

[Sprocket]

I'd rather fit the correct gears so that the speedo is still original. There are enough combinations of speedo drive gears to get it as acurate as required. This way you dont have the wrong speedo gears and an altered speedo, seems a little daft, but if its the same price then i supose its up to you.

Calibration is dependant on you suppling acurate measurements of the rolling radius/ circumferance of the wheels.

[Dan]

Speedy don't do it all based on gearbox maths alone, they help you out a bit with the accuracy. They ask you to measure accurately to within a certain amount of 1 revolution how many times your speedo cable turns for 6 turns (why it's that many I can't say) of the road wheels. You take out your speedo, stick a cardboard arrow on the end of the cable, chalk the tyre where it touches the ground and push the car straight along the road until it's turned exactly the right amount of times and count the number of times the arrow spins. Then they get you to measure exactly how far your car travels in those revolutions and stuff like that. Absolutely bizarre ritual but it does seem to give an accurate speedo. Easy ways of getting accurate measurements by averageing it out I suppose rather than judging it all from a direct measurement.

The only reason I got mine done was because it's an aftermarket speedo and not a genuine one. The gears in the gearbox are right for the FD, wheels and engine so we got the speedo calibrated to that rather than play with the cogs and end up as you say Sprocket with the wrong speedo and the wrong gears. So the speedo has been calibrated to the standard Mini TPM for this age of car I suppose.

I don't think it was as much as £60.00 though but it was a few years ago.

Edited by Dan, 01 June 2006 - 12:17 AM.

[blacktulip]

what would be the easiest way to get a proper reading? say i fitted a 998 from a late mini with 3.1 ratio. would it be to send it away for calibration?