hugh at sol.co.uk wrote: > Ian, > > Interesting tale. > > What kind of turbo RPM sensor is fitted to your car? As yet, none. Im hoping to use a simple led/phototransistor to pick up pulses from copmpressor blade edges, then get my computer to do a divide by n where n = number of blades. My hope is the curvature of the blades will be enough to get 1 pulse/blade out of it.