G-force meter.Almost as good as a dyno:)

[Lowell]

These guys reckon you can get reliable results at a dragstrip, but then, they WOULD say that :lol:
I wonder if it is MORE reliable on a smaller slower vehicle, or less?

They're most accurate on moderate accelerating vehicles, around .5g or so where there's little front end lift. On the low end of things, the sensor resolution becomes an issue, and on long pulls small errors add up to large speed errors by the end.

The good thing is that if you use the same road all the time, the results are pretty consistant, so it's easy to measure gains.

 

[Jozzer]

Thats what I wanted it for
I'm getting consistent times at least, I ran 4 tests down the same hill this afternoon and got 4 readings within 0.7 secs of each other.
Now I just got to find me someone in the USA who will order a cable for me and post it on to Blighty