I need help with tach controled underbody lighting for my I30

[t3h j1zzy]

ok first off im making my own underbody kit....it so far consists of 10 super bright LED's on each flank of the car...im working on a circuit to be able to make the leds light up(in seqence) according to how high i have it tached uplike so i get 2 or so leds to light up per 1k rpms lighting up from front to back....so far ive found an ic to control the bargraph function of this (LM3914)...im just not sure how to get the output from the car to tell me the tach rpms digitally...PLEASE HELP...cuz i think that might look pretty neat

[t3h j1zzy]

or if anybody knows of a company that sells a kit like that

[audtatious]

Ah. OK...

Auto stores actually sell LED bar tachs as it is. You could probably steal the inner circuit and use those to control your external LED's. That would be far easier than trying to build your own.