I have an'81 Pontiac Firebird that I bought about a month ago and I noticed the speedometer is vacuum operated and only registered up to 85 miles per hour.I Was wondering if anyone knew of any of them that were electrical and registered 200 mph. Any Help/input would be greatly appreciated thanks in advance.
-Polk540  

Could you get an aftermarket speedo? and when are you going to get a '81 firebird up to 200 mph?  

Hopefully by putting a six speed in it and an engine thats got horsepower out the ass.And its not that I need one that goes two hundred because my car goes that fast, its just nice to have one that doesn't stop at 140 mph when I know I'm going to do more than that. (
All the after-market ones I have found stop at 140mph.
-Polk540

NOTE: this is Polk540 server wouldn't let me log back in for some reason...  

Jegs actually has a few that go 180 but 200 would be nice.Just because.  

I looked around a little, but i couldn't find anything that went to 200.  

Well I found a few of them on Jegs so I guess this thread can be clasified as closed unless someone wants to find one that goes higher than 200.  

if your cable driven speedo has metric range on it also... there was an ratio adaptor to slow down the cable to make it accurate in mph on the kph scale...


with a gps unit and an external antenna you could see exactally how fast you are going and how far you have gone.. except in parking garages and in tunnels..


a few guys were discussing that for salt flats racing... that elimanates wheel slip from the speedo readings...and with more expencive units you can download the trip data into a pc to review your speeds and course..  

Sorry haven't been on here in a while.
How much is one of those GPS units you're talking about?

Know of anyplace to get a replacement gauge cluster for it,preferably with a tachometer? If not I know there's a conversion available to convert it from vacuum operated to electronic but I don't where to get it...  

You might want to see if anybody in the aircraft industry has what you need. When I think GPS speedometer and 200mph, the only thing I come up with is aircraft avionics.  

wow this got twisted...

#1 speedos are cable driven (except for the ones you wear)

#2  trans am's and formulas may have the tach option.

#3  GPS units come from electronics dealers like radio shack and circut city and others.. most have a port for an external antenna...you can mount them on the dash and have the antenna on the dashboard ... boats use them to navagate... they come in really handy... more expenive units are used in aircraft as a back up navagation device...
google garmin, or magallian....or just    hand held gps...

using gps will also elimanate the slip in the drive wheels which could throw off the speedo reading.. and even better is you can show your friends how fast you really were going at a later time....

#4 speedo ratio converter boxes can be had at any speedo shop and will allow you dual speedo to read the metric scale as miles per hour... the screw on right at the side of the transmission and the cable screws onto them...  it will take longer to jack up the car than it will to hook up the adaptor....