Hi,

I have a yellow box speed healer but it works in % difference and i dont have a clue how to work out the % between my car and the bike.

I have the following setup:

R1 2002/2003
3.62 diff
195/45/15 wheels

Any ideas how i would work it out?

Cheers

[Edited on 27/2/09 by Pdlewis]

There is an online calculator on the Healtech website. I used this to calculate an 01 R1 and it was spot on according to GPS. Just adjust the sprocket size to give you 3.62:1 as accurately as you can. You should end up with a figure of around -30% or so. If you struggle, give me a shout and i'll work it out for you

http://www.healtech-electronics.com/

PS those tyres are a high profile - definately a 65 profile? Most use 195/50/15's dont they

[Edited on 27/2/09 by Paul TigerB6]

Sorry they are 45 no 65

Curiosity got the better of me - i make it -38.8% then

Oh c@*k I have a yellow box v3 and it only goes +/- 28%

Yeah I had to change my yellow box (as fitted to the car when I bought it) to a Speedohealer as it was on max adjustment and was still overreading on the speed (and therefore the odo) by quite a margin.

Ooops - sorry!!

I take it all back - its 28% - honest!!

Dont forget to put in a bit of leeway to get through SVA - maybe -40% or so

Cheers for the help at least i know the setting for when i get a different unit.

bit gutted after fitting it today

I can confirm that the yellow box won't do for your setup. I only just got enough correction with mine and I'm on a 3.21 diff'.

adrian