For what it's worth I have found that 1152TPM is the closest calibration I
could get to suit the set up on Bluehealey. I have a 3.54 Lempert diff on
overdrive box with 180XAS Michelins. Rolling radius of those I found to be
The set up uses a 32tooth worm wheel and 36 tooth Odo wheel. The displayed
mileage and actual mileage are pretty close and have been checked over a few
hundred miles against a Sat Nav. Error is about 1-2%.
Your tyres will be the only variable with my arrangement.
Speedo calibration is all over the place. I just moved the needle, relative to
the drive cup, until 60mph matches my sat nav display. All other speeds above
and below will be off a margin.
Give me your rolling radius of the tyres and I will be able to provide the best
Turns per mile sett up.
Alan - from my iPad
> On 4 Dec 2016, at 19:32, Bob Haskell <email@example.com> wrote:
> What's the thickness of the washer that is fitted between the gearbox and the
> right angle drive (PN 3H550 or Moss PN 324-720)?
> There are two MPH speedometers fitted to the 3000 MkI and MkII; one for
> overdrive and one for non-overdrive cars. What's the speedometer calibration
> (turns per mile) for each?
> BMC P/N Smiths P/N TPM
> non-OD BHA4124 SN6155/19 980???
> OD BHA4126 SN6155/21 1080???
> When fitting a 3.54:1 rear end to an overdrive equipped car, does the non-OD
> speedometer have the correct calibration? I think that it would if the gear
> ratios for the speedometer takeoffs on the extension housing of the non-OD
> gearbox and on the overdrive were the same. If not, what calibration (TPM)
> have folks used?
> Bob Haskell
> AHCA 3000 MkI registrar
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation $12.75
> Archive: http://www.team.net/archive
> Forums: http://www.team.net/forums