Speedo calibration

[MHunter]

I got myself a GPS system to calibrate my speedo. To match the speed the GPS was displaying, I had to turn down the speedo PPM to 5000, from the normal 6400. I'm not sure what would account for that difference. I've got factory wheels with recommended tyre size.

strange?

[JoulesCanAm]

How many teeth does your sensor trigger wheel have?

Julian

[Steve_D]

Perhaps the 6400 came from the F1 tyres. The latest tyres they use may have a different rolling radius.

Steve

[MHunter]

JoulesCanAm said:

How many teeth does your sensor trigger wheel have?

The sensor wheel has 6 teeth.

[ROWDYRENAULT]

A suggestion to new builders, Speedhut a U.S. company, has a round speedo that has the gps in the unit. You can order a wide varity of colors styles fonts ect. You can even order the unit with your own design logo on the gauge. This might be a good way to go no sensor wheel no speedo cable just a thought. Lee

[Steve_D]

ROWDYRENAULT said:

A suggestion to new builders, Speedhut a U.S. company, has a round speedo that has the gps in the unit. You can order a wide varity of colors styles fonts ect. You can even order the unit with your own design logo on the gauge. This might be a good way to go no sensor wheel no speedo cable just a thought. Lee

Unfortunately this would not pass our IVA test. The speedo test is carried out on a calibrated rolling road.

steve