holy shiznit!
Using a tach as a speedo
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From: Gig Harbor, Wa
Using a tach as a speedo Tell me what you think of this idea. My speedo and tach are the same size with the same sweep to the gauge face. I am thinking of taking a tach and swapping the speedo gauge face onto it then either using one of those speedo ratio calibrator things or maybe tuning the PCM to give out the right pulses per mile.
Last edited by 70 LS1; Aug 4, 2006 at 10:17 PM.
who needs a speedometer? that'd be awesome if it worked, you dont REALLY need the translator though.. just tell your passengers your car is so fast that it jumps back in time, and that's why your speedo drops 30mph every time you shift. if all else fails, just grab a VSS speedo out of something else and merge the two. Keep us updated.
olly
olly
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From: Gig Harbor, Wa
It wouldn't drop when you shift. The tach signal and the VSS signal are very similar. If you put the speedo face on a second tach and hooked it up to the VSS, then it should work just fine as a speedo after you calibrate it.
I think I'm going to have to try it.
I think I'm going to have to try it.
you wont have a Odometer this way......
personally, id jsut send the gauge off to be converted over to a electronic speedo. while i havent done it, i know there are companies out there that do that sort of thing.
personally, id jsut send the gauge off to be converted over to a electronic speedo. while i havent done it, i know there are companies out there that do that sort of thing.
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From: Downers Grove, IL
A few people have converted their mechanical speedos to electric so far. The only tricky parts are designing the new gauge face (unless you get lucky enough to find an electronic speedo with the same spacing as your factory speedo) and finding an electonic speedo with an odometer that lines up. I ended up cutting the odometer hole in my factory face so that I could read the odometer and then using my new overlay face to cover the old odometer hole. I didn`t really search too much for a perfect line up since I found an autometer electonic speedo on e-bay for $30. It even had an old style mechanical odometer instead of digital readout. I was able to just remove the pointer, put it behind my speedo face and drop the pointer from my original el camino speedo right on.
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From: Gig Harbor, Wa
Thats cool, G-Body. The sweep on my stock gauges is way too much for an autometer. The electric tach is basically a speedometer that takes pulse inputs and displays an output. By swapping the speedo face on one, it would act the same but instead of showing engine RPM it would show speed which is basically derived from trans RPM.
Joined: Sep 2004
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From: Downers Grove, IL
I didn`t look at the pic last night. You do have a large sweep on that face. I think that using a tach will work since I believe the tachometer signal is considered a square wave DC signal and that is what the PCM puts out. And I know that with EFI live 7 you can change the pulse output of the PCM since Jesse did that on my computer so that my cruise control would work. That would allow you to calibrate the tach/speedo. 