Converting to a GPS Speedo

Ehlien

Ehlien

Member
I have a 49 Merc flat head 8 and trans. I am trying to determine the feasibility of converting from a cable driven to a GPS activated but I do not know much about them or how they are installed etc. Any info that anyone could provide would be greatly appreciated..
 
My old Tom Tom GPS is pretty accurate, seems like any GPS conversion would depend on a good satellite signal.
 
I have been looking at them but never used one (the type of GPS that actually sends a signal to a speedometer). I would also be interested in any real world experience with one. My "top of the dash" GPS always seems to provide accurate speed information.
 
I bought a GPS sending module and installed it on my AV8 intending to use it with a SW Wings electronic speedometer. Would not work even tho the instructions said it was compatable with most electronic speedometers. After several calls they admitted you should use it with a specific GPS speedometer such as Autometer makes.

So if you want to go this way be sure to use compatible units.

Bill
 
I am running Classic inst. Skydrive with a S/W Deluxe electric speedo. So far, 6K miles and works very well.
 
After issues with the mechanical speedometer drive to electric SW unit I purchased a GPS speedometer. It connected and calibrated and works well some times
Be aware of the following:
1. The unit must lock on to a satellite. This can take several miles.
2. The unit need to be placed as far from overhead metal as possible. Mine is under the dash and I do not recommend that placement even though the instructions indicate it is OK to put it there.
3. I encounter dead spots where the unit stops working, I assume this is spotty satellite coverage.
When it works it is dead on, I have checked it against my iPhone app. However the erratic operation makes checking mileage impossible. Knowing what I now know I would not buy it again.
Hope this helps good luck.
 
From day one I had no speed indication in my 32 roadster, SW Wings electric speedo with signal generator in mech drive of trans. As my luck would have it, these wires from trans are the only wires I ran under my glued down carpet. So....purchased a gps sender from Summit, simple install, my speedo snaps to 0 as it should when key on, needle cycles as it should while driving the measured mile, but in the end ...... no speedo. Is there a way to test if there is signal from the gps receiver or my mech sender for that matter?? What are the odds of the speedo being defective although it works as it should through programing mode??

Any thoughts welcome,

Shoebox
 
I used an Autometer GPS unit in my F-1 and it worked perfectly. Had the receiver on the dash and not much slant on the windshield but it didn't seem to matter. I wouldn't hesitate to buy another if needed. It is simple to calibrate if changing tire size or axle ratio.
 
I spoke to the folks at Classic and they recommended a dedicated ground for the speedometer. They have found that sometimes a shared ground with the other gauges will allow the speedometer to react badly. When I installed mine, I ran a redundant ground to the chassis along with the series ground of the gauges. Perhaps that is thereason I have had no problems so far. I hope writing this doesn't jinx the set up!
 
Classic Instruments Skydrive unit, used with their speedo on my glass 32 5 window. No problems, worked great out of the box. Takes about 30 secs for the unit to acquire a signal when first starting out, then rock steady and accurate. Will use one on the roadster I'm building.
 
I have two Classic Instruments SkyDrive units, one in a 39 coupe with the sensor mounted under the package tray (kinda in the back window) and one in a 32 roadster with the sensor under the seat in the center. For the 39, it has always worked perfect. For the 32, I was having some intermittent operation events and discovered that there were wires laying across the top of the sensor....moved the wires and all is well. The SkyDrive is super easy to calibrate, takes maybe 3 minutes. I recommend them.....I haven't tried the speedo in a long tunnel but who looks at their speedo in a tunnel anyway?
 
Tony said:
Read different results on this install. Some couldn't get it to work. Wondering about this one. A reviewer got it to work with some difficulty.
http://www.summitracing.com/parts/izl-s9020/overview/
I'm ready to buy one, so need some more experiences by others.
Click to expand...
Since I have SW Wing gauges, I looked hard and decided on the Dakota Digital GPS Interface Module and optional antenna. Just installed it. Only driven around town, no high speed driving yet. Works fine. Easy to set up.
http://www.summitracing.com/parts/dak-gps-50-2?seid=srese1&gclid=COSQl5uBicgCFYYRHwodO7MNxA
 
What's this world coming too! I like old cars because they are not the complicated with new technology.ie. OSBII ports, tire sensors ect. Saying that I try not to use my computer more than 1hr. a day. Ha,ha
 
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I also used a Skydrive unit on a glass car due to interference issues with the trans and exhaust. No issues except the 30 seconds to lock on a satellite and going through a tunnel.
 
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