lal_truckee wrote:
Humsquirto wrote:

72mph! I'm pretty sure the GPS speed indicator is accurate, ...

I profess a slight doubt...

I would drink to that doubt.

There is a GPS option available for many data acquisition systems most
drivers find that you get more repeatable results from a lateral
accelerometer and a wheel speed indicator non driven wheel. There is a
fair amount of error in the gps system, my thoughts also when you get
height changes z axis the calculations are not that accurate vs on a
road where you just measuring x y axis changes

I can show you some funny errors such as going off track on to grass and
show a speed of 203 from the gps calulation, he was doing 95 before
leaving track. yesterday I was chasing a 158 mph high on one lap the
calculated max speed of car at 9000 rpm is about 144--- 145 13 mph over
is one big draft or a gps error