I'm just interested to see if anyone has ever considered using any of the GPS and/or accelerometer based data acquisition systems to measure the HP gains from a change in for example the carburation main jet sizes etc.
I'm not about to go spending silly money on one of these systems but I have just bought a 5Hz GPS data logger fo $99 and I reckon I can manipulate the data in such a way as to give me at the very least relative measurements to compare different setups on my bike. I know 5Hz is on the low side but If I can get a simple system to improve on my useless butt dyno I'd be happy. I'm assuming that at the very least, speed and accelerations readings would be fairly accurate given the good repeatability of GPS data. As for converting to horsepower estimates, although using a rough estimate of the total bike + rider weight would not give very accurate actual HP numbers it would at least show relative gains or losses which is all we really care about during the tuning.
Just a passing thought, I'll let you know how I get on with it over the next few weeks.
Also I'd suggest checking the BT Q1000 out. It's cheap, data logs 70,000 points, maps your route and speeds onto google maps and can be setup in a 5Hz mode which should be sufficient to give fairly decent acceleration measurements.
All thoughts or previous experience on the matter are welcome.
I'm not about to go spending silly money on one of these systems but I have just bought a 5Hz GPS data logger fo $99 and I reckon I can manipulate the data in such a way as to give me at the very least relative measurements to compare different setups on my bike. I know 5Hz is on the low side but If I can get a simple system to improve on my useless butt dyno I'd be happy. I'm assuming that at the very least, speed and accelerations readings would be fairly accurate given the good repeatability of GPS data. As for converting to horsepower estimates, although using a rough estimate of the total bike + rider weight would not give very accurate actual HP numbers it would at least show relative gains or losses which is all we really care about during the tuning.
Just a passing thought, I'll let you know how I get on with it over the next few weeks.
Also I'd suggest checking the BT Q1000 out. It's cheap, data logs 70,000 points, maps your route and speeds onto google maps and can be setup in a 5Hz mode which should be sufficient to give fairly decent acceleration measurements.
All thoughts or previous experience on the matter are welcome.