Inaccurate Tachometer?

[infernosg]

Originally Posted by infernosg

I'm halfway there. The tach is now being run by a Haltech but I'm still using the stock speedo cable until I rig something up for a Hall effect sensor or the like. Too bad I didn't jump on those trigger wheels being sold a while back. I'm not sure about a digital display but one day the car will have a custom instrument cluster.

I'm now working on the custom gauge cluster. I'm using analog gauges and the tachometer is still going to get its signal from the Haltech but I need to identify a source for the speedometer. I can theoretically use any signal for the speedometer as long as it produces between 4000 and 200000 pulses per mile. Some options I'm considering:

1. Keep the mechanical speedo cable and isolate the speed output from the stock cluster and use it as a signal source.
2. Hall effect sensor + trigger/magnetic pickup wheel on the driveshaft (there are some pre-made options out there that look like they'll work).
3. Hall effect sensor + trigger/magnetic pickup wheel on a front wheel hub (a la TII ABS sensor)
4. Use FD VSS (will this even work in a N/A transmission?)

Thoughts?