Hey.....I'm thinking about doing this crazy conversion car, and I'm not sure how the speedo/tach really works..

It's my impression that the ECM has a vehicle speed sensor thingy..or something.. Well, this project will be carbed, so there will be no ecm..

I'm thinking about probably a 2004r or turbo-350 transmission in it.. Is there an electrical signal off of that that reports driveshaft rotational speed? Where would I get the RPM signal from?

What I really want is some sort of varying signal........like 0v = 0mph, 5v=100mph, or something like that... I can scale it to whatever I need..

Any ideas, anyone?

Thanks,
-Tesla

------------------
91 T/A 305 tpi SD
STB, Airfoil, Hooker cat-back, pseudo-cold air to K&N, Accel coil, !cat, !smog pump.
The Wankel Rotary Engine - The replacement for displacement.

 

Up to '89 the speedos are cable driven - except for some T/As & Berlinettas, in which case there is a VSS and VSS buffer (yellow box). In '90 - '92 the speedos are all electric & the VSS buffer is built into the ECM. If you don't want an ECM, you could get an external VSS buffer box & hook it to a VSS - if a 700R4 VSS will fit in a TH350. The output of the VSS buffer is 4000 pulses per mile with the correct tailshaft & VSS gears installed.

Tim