Speedo Calibration

[morebeanz]

Having had my speedo fixed by not so Speedy Cables, I have found that it is under-reading. A search on the web suggests that the calibration might be adjustable using a PPU number, and that there is a protocol for setting it in situ using the LCD display for the odometer.

Before I go messing about with such things, does anyone have specific knowledge on whether that applies to the Cerb speedo, and

if it does, does anyone know what the PPU is for a 4.5 cerb?

Thanks!!

[Dollyman1850]

I have a smiths electronic one with an electronic LCD on Dads Vixen.

It can be calibrated by PPU or Drive to set. Have a look at the instructions which are downloadable from the net for a smiths gauge and it may be that you can do it for the TVR one in much the same way... There is a way to work out PPU but it may not be accurate. I measured a mile in 2 cars then marked the position on the road then used the drive to set function... You may hit lucky or the TVR instrument may be nowt like the smiths one
N.

[morebeanz]

Thank you!

Having read the instructions, I can't imagine where I might get an accurate road mile to measure up. On sea they have measured miles, but I guess for cars, everyone would be trying their timings!!

[FarmyardPants]

You could do a steady 60mph, measured using a GPS, for a minute. Or 180mph for 20s