Don't ask me why, maybe it's 'cause I'm a child of the eighties, but I seem to have a desire to put a digital speedometer readout on my dash, ala what Doc put in his Delorean in Back to the Future.

I figure I have three options: a standalone unit that measures force, a unit that connects to the OBD port ( I have no idea what kind of port it is, '89 Firebird Formula), or something that plugs into the original speedo's signal, which I really don't want to deal with.

Does anyone have any suggestions? What kind of OBD port does my 89 Formula have and does it output the car's speed? If I can get information on how to interpret the speed signal from the data port, I can fabricate my own unit, as I am a complete nerd.

 

No options other than a replacement instrument cluster, gotcha.

 

Could make your own but its not easy. I designed one using a programmable microcontroller that ran directly off the speed sensor from the transmission. Never got around to building/testing it though and I dont know if I'd want to anymore. And I used to be very bored. Took me 3 months of my spare time.

Maybe could go through the OBDI port and do some conversions but that seems a lot more complicated than going off the speed sensor. However, i dont know much about going through the data stream on the OBDI port.

 

If GM wasn't so **** about their '80s-era corporate secrets, I'd make something with parts from Radio Shack using information about their OBDI interface. Wouldn't be hard if I had the right data.

God bless OBDII, and too bad third gens were a few years too young for standardization.