diy mpg gauge

[itjstagame]

Actually thinking a bit more I'm pretty stupid to need rpm signal. I can easily get that from the injector pulses! I guess the only difference is that as their duty cycle changes the peaks may start or stop at different times causing a very miniscul shift, but the Hz*2 should be rpm.

In fact if you just had your program ask for the gearing ratios of the transmission and final drive, as well as tire diameter and size, as StreetDyno does, then you wouldn't need VSS either, since you could calculate speed based on RPM. Of course you'd contantly have to tell it which gear you were in on the fly....