Aftermarket Speedo

[TG Goose]

Has anyone successfully connected an aftermarket electronic speedo to their car? I'm looking at getting a track car and would wire it with aftermarket gauges just for reliability.

I'm going to use Autometer gauges as I have the gauges already for an old project that I got rid of.

[bmwman91]

For some reason I was thinking that this was going to be about awkward swimwear.

A web search for "universal car speedometer" yields a lot of hits. Autometer seems to make a variety of them. For the most part, it looks like most speedometers offer a lot of calibration & tuning options, so they would probably work fine with stock sensors.

[TG Goose]

I've been reading the instructions for the Autometer, but I dont know which wire off the diff sensor to tie splice into.

[bmwman91]

http://www.armchair.mb.ca/~dave/BMW/e30/e30_92.pdf

Page 52 has the diagram (for a 318iS anyway). Brown wires on BMWs are (almost) always grounds. The other one is the output.

[TG Goose]

could I use the wire from the cruise control? ie the one wire that plugs into the back of the speedo

[30THIRTY]

I would think you could use the speed sensor in the diff