[Chris LaPanse]

The best way is a speed trap where it has two sensors a short distance (~10 feet) apart, and it calculates speed based on time between the sensors. That is how they do it in drag racing.

[e_lm_70]

Originally Posted by Sigurd Ruschkow

A GPS is useless at these speeds and these accelerations. Most boat racers who race SAW know that. The problem is not the accuracy of the GPS
it is the short time intervall the GPS has to measure the steady state speed.

Strange,

I use my Garmin 201 for mesure speed up to 190km/h and I didn't find any problem (used inside a real car).

The only limit of the GPS it is that they make a mesurment every seconds, so you need to keep the top speed for 1 second (better a couple) in order to get an accurate result. In case you can't keep the top speed in a sustained mode, then you get as result the best avarage speed inside a second time frame. That could be different then the top instant speed.

If you have a GPS around, it would be nice to use it for compare the result from the speed gun.

Anyhow, sorry for the little bit out of topic ...

And me to I'm very curios to hear news about your improvements.

e_lm_70