Thread: Electric Speedometer

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Hi All,
How does an electric Speedo work? Can I add one to my '48 Chevy? I hope this isn't a stupid question.... Lol!
Thanks Guys,
Mack

You'd replace the speedometer gear in the transmission with a sending unit. Autometer and a number of other companies sell them. Big advantage of an electric speedometer is that it's very easily calibrated with just a bit of button pushing!

My newest set uses a GPS module connected to the speedo and you simply turn it on, press another button and you're done! Nothing to connect under the car!

Thanks guys!
CHR, what brand is your set? Sounds perfect for me.

Mack,
If you Google "Automotive GPS Speedometer" you'll get a wide array of offerings. There's also a GPS driven unit to feed just about any electric speedometer (if you already have one?), but it's in the $200 range and is a 6"x6" box plus hardwired antenna - Auto Meter My question, I know that they use the latest high speed GPS interface and look at multiple satellites for accuracy, but how do they do if you get in areas where the "view" of the satellites is compromised, like heavy tree cover, heavy cloud cover with storms, etc?

Mike (CHR ), does your unit have any type of remote antenna that needs clear view of the sky as opposed to being in the dash, surrounded by metal/fiberglass?

I'll assume you're addressing me... I went with Classic Instruments, and their system is called the SkyDrive.

Originally Posted by rspears

Mike (CHR ), does your unit have any type of remote antenna that needs clear view of the sky as opposed to being in the dash, surrounded by metal/fiberglass?

RSpears.. The SkyDrive is smaller than a pack of cigs and they do say to give it a clear view of the sky, they also "hint" that it does operate out of site and that you can test it for yourself out of view.

I've got mine under the dash so it's surrounded by the fiberglass and all the wiring and it seems to work well. I haven't selected a final location as I was going to move it to the rear package tray and test it there. If I don't see any improvement in the performance, I'll leave it under the dash.

Originally Posted by 34_40

RSpears.. The SkyDrive is smaller than a pack of cigs and they do say to give it a clear view of the sky, they also "hint" that it does operate out of site and that you can test it for yourself out of view.

I've got mine under the dash so it's surrounded by the fiberglass and all the wiring and it seems to work well. I haven't selected a final location as I was going to move it to the rear package tray and test it there. If I don't see any improvement in the performance, I'll leave it under the dash.

That fits with what I've seen, and I think they "see" through fiberglass better than metal but I wouldn't swear to that. My GPS locator unit sends me messages almost daily that it has "...lost signal" sitting in the garage against the wall farthest from the windows, and in the metal barn it's a lost cause. I expect a long tunnel will be the same, but it's not a big deal to track by the tach if the speedometer drops out when blinded. They're drop dead accurate on speed.

Originally Posted by rspears

That fits with what I've seen, and I think they "see" through fiberglass better than metal but I wouldn't swear to that. My GPS locator unit sends me messages almost daily that it has "...lost signal" sitting in the garage against the wall farthest from the windows, and in the metal barn it's a lost cause. I expect a long tunnel will be the same, but it's not a big deal to track by the tach if the speedometer drops out when blinded. They're drop dead accurate on speed.

I'll agree with all of that. I haven't been in a tunnel with it but if I lost am or fm radio signal then I'd expect the gps to go away also. I don't see it as a problem though.. and how often do you really watch you're speedo? Like most, you glance at it for reference once in a while. The other thing is the actual gauge can also be used with the tranny sensor and calibrated by the usual drive one mile push the button etc. etc. So, even if you change you're mind about the gps system, you can always connect it to the transmission.

Thank you all again!
It was a few months back y'all helped me out with brake system issues & got that squared away! The '48 coupe is going for inspection sometime this week, need to replace a homemade trans crossmember that's sagged first.
Thanks again! You guys are awesome!!
Mack