Ok new idea for datalogging rpms.. i found that it is not as simple as you may think datalogging one wire.. because it is a pulsed signal.. now the next idea.. I am looking for incite on this because it is just an idea as of now. I am going to cut the end off of a timing light and record the voltage of when it gets a voltage.. then there must be some calculation to figure out how often the pulses are to determine RPMs.. the more pulses (spark plug wire getting voltage) the higher the rpms.. anyone try anything like this before? Thanks guys!

 

anyone? I know there's a lot of DIYers out there!

 

Why don't you just put a frequency to voltage converter, on the pulsed signal from the distributer? it will give you like 0-5V for 0-8k rpm.

 

where do i get a frequency to voltage converter? And what is it exactly?

 

National Semiconductor

LM2917 - Freq-to-Voltage converter

 

interesting. i wonder if this is something similar to the way that the pivot shift light reads rpm. great info. keep us updated. thanks.