GPS Speedometer
- Thread starter RPMagoo
- Start date
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rustycowll69
Well-Known Member
I kinda question the viability of gps speedos. I remember back in the late 1990's when the GPS signals were subjected to "selective availability"(deliberate limits to accuracy). I've also heard that the powers that be were going to change the system, and obsolete old gps receivers. If there ever was a national emergency, like 911, they would "turn off" the satellites availability to non military apps. Now maybe we are so past that point of common use, that that could not happen, I don't know.
Autometer and Holley both make them. Also a company called intellitronix in Cleveland. Not sure if any of the internals are usa or not.
RPMagoo
Just An Old Motorhead
-- I thought that they are round / in dash type ? -- I'm looking for one that sits on the top of the dash
If you are cheap like me, get a holder for your phone & a free app
RPMagoo
Just An Old Motorhead
-- I'm cheaper than You. I have a old fashioned flip phone. -- I can use My Garmin GPS, but I am hoping for a dedicated speedometer.
I would have to agree with that...anything just plopped up on the dash is Probably less accurate than a $1 app on a cell.
RPMagoo
Just An Old Motorhead
-- The Garmin, when sitting on the dash, is very accurate. -- Perhaps a, dedicated, speedometer, of the type that I would like is not made.
Idk if you are going to get usa made, but this one does hud and normal.
https://gearboo.com/products/gps-un...ium=cpc&utm_source=google&utm_campaign=Google Shopping
https://gearboo.com/products/gps-un...ium=cpc&utm_source=google&utm_campaign=Google Shopping
RPMagoo
Just An Old Motorhead
My problem is -- I have a 64 Falcon Sprint (I Know it's a Brand X) with a AOD transmission, 8" rear, 3.80 ratio, and 245/60-15" tires. The speedometer drive gear in the transmission is a 8 tooth and with My setup the correct driven gear is a 23 tooth. -- I haven't been able to get a 23 tooth gear that works without being chewed up. It seems that they all enter into the drive gear at the wrong angle. The max OEM - Ford gear is a 21 tooth. -- Currently I am using a 21 tooth gear, and My speedometer is off by 10%.
RPMagoo
Just An Old Motorhead
-- Thanks. -- I ordered one.
rustycowll69
Well-Known Member
there used to be speedo adapters available, which were little boxes which were like 2" long x 1" x 1", and screwed to your trans and accepted the end of the speedo cable. I've seen them made out of bakelite or aluminum. within the box there are little nylon? spur gears, of various numbered teeth, to alter the final ratio in conjunction with whatever speedo ratio in the trans. My 76 dodge w200 came with one from the factory.
is there some aftermarket misinformation on a 4r70w vs aode on gear type? Ever call TCI or performance automatic?
Back in the day a guy at a ford dealer showed me how to cut down a speedometer gear for a transmission/ rear end combo that was never available. Don’t remember the details from 40 some years ago, but it was a longer gear that had the right number of teeth that I cut down to a shorter one.
rustycowll69
Well-Known Member
Matts440
Well-Known Member
Speedhut has them and made in the USA
I use the Ulysse speedometer app for my phone.
free download.
if you pay for it it does all sorts of tracking and calculations.
I verified it's accuracy on three different vehicles and it's pretty much spot on.
free download.
if you pay for it it does all sorts of tracking and calculations.
I verified it's accuracy on three different vehicles and it's pretty much spot on.
I bought one of those for my 73 Duster....tested in my 2016 Dodge ram.....worst case at 75 mph the gps showed 73......so which one is right...
Remember that pre-circa 2005-ish GPS (and really any new cheap GPS) can be 10 meter instead of IIRC 2 meter accurate, making the true speed lag way behind the displayed speed.
I've read quite a few reviews of the new cheap units where the accounts of poor performance suggest this could be the case.
I've read quite a few reviews of the new cheap units where the accounts of poor performance suggest this could be the case.
I use the speedhut gps unit (built in 2015)with absolutely no issues. Its been accurate,shows elevation and can record incremental times (of which I've compared to time slips with no error)It could be mounted in a "cup" if necessary
I don't think that any of this is a concern these days. Besides, in the case of a national emergency that was serious enough to shut down civilian use of GPS, I think you're in the clear to speed a little.
RPMagoo
Just An Old Motorhead
-- Is this the one ? https://www.amazon.com/dp/B07FNHGRZ9/?tag=joeychgo-20
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