Autometer Sport Comp Mechanical Speedo on w58 question

[empera]

has anyone installed one of these? Need a speedo in my datsun and was thinking about going with the GPS speedo but they are way expensive. I believe i will need to know what the ratio on the w58 speedo sensor is.....the sport comp/autometer needs it to be 1:1 , is the w58 1:1? I dont believe this trans has a TCCS? If so i would consider an electric gauge.

Any input or suggestions?

 

[empera]

Any one???

 

[Dan_Gyoba]

Well, it's the differential ratio and tire size that are going to make the difference. If you're using an A70 W58 then the output with a 4.300:1 differential and 225/50R16 tires will have the speedo cable rotating 637 revolutions per kilometer or 1026 revolutions per mile (As per info printed on the A70 gauge face)

Given that, for a different tire size and differential ratio, you should be able to make adjustments so that an adjustable mechanical speedometer can be used, however, if it is using the ABS sensor... Then I have no data to convert pulses to distance. Looking at Autometer's site, it appears that it uses a sensor like the ABS sensor, and that you use a callibrated drive to set it, so it doesn't matter.

I do know that the ABS sensor is in the tail housing of the transmission, so it will be consistent with driveshaft speed.