47-59 Speedo and Tach question

[TX3100Guy]

My 1953 truck has a 1959 261 cu/in engine and a four speed GM transmission. The transmission has the traditional speedo gear and cable setup to a mechanical speedo. The tach is driven by a mechanical tach generator mounted on the shaft of a magneto, not a distributor, with a cable from the tach generator to the dash tach.

I'm thinking that I'd like to convert the cable driven tach and speedo to a more electric version (not digital) and have been searching for some kind of sensors that would replace the cables from the tranny and the magneto tach generator and that would pair with a new set of dash gauges (speedo and tach)

Is anyone aware of a product(s) that would allow me make this transition?

[e015475]

Speedhut sells a speedometer drive called a SpeedBox that takes either a GPS signal of input from a CAN bus to drive a stepper motor that turns a conventional speedo cable.

I have a transmission that doesn't have an electronic signal or a speedo gear drive, so I use the SpeedBox to drive my factory speedometer.

As for your tach for a magneto, Autometer makes a tach adapter that produces an electronic signal for a tach off of a magneto - Autometer part number 9118.

You can get your checkbook out and save yourself a lot of hassle with some Dakota Digital RTX gauges. The speedo is driven off of a signal generator that hooks to your transmission cable, but I think there's a GPS option too. I'd guess you'd still need the magneto adapter from Autometer to get the tach to work

[TX3100Guy]

Originally Posted by e015475

Speedhut sells a speedometer drive called a SpeedBox that takes either a GPS signal of input from a CAN bus to drive a stepper motor that turns a conventional speedo cable.

As for your tach for a magneto, Autometer makes a tach adapter that produces an electronic signal for a tach off of a magneto - Autometer part number 9118.

Thank you. I've seen and reviewed the Autometer product, but found some conflicting reviews on its operation with my Vertex magneto. Does anyone here have any experience with it???

I'll look into the Speedhut products too. How well does the GPS speedo work for you?

[e015475]

I had a lot of issues with the SpeedBox, and I think most of it was self-inflicted.

It only seemed to work intermittently until I relocated the ground, but now seems to work well.

I think the first one I had was an early production unit and I sent it back and Speed Hut said no fault found but updated it to the latest configuration and sent it back to me, no charge.

It did the same thing as the old one, so I went looking for proper grounds and that seems to have done the trick.

Speed Huts customer service was very good.

[TX3100Guy]

Originally Posted by e015475

I had a lot of issues with the SpeedBox, and I think most of it was self-inflicted.

It only seemed to work intermittently until I relocated the ground, but now seems to work well.

I think the first one I had was an early production unit and I sent it back and Speed Hut said no fault found but updated it to the latest configuration and sent it back to me, no charge.

It did the same thing as the old one, so I went looking for proper grounds and that seems to have done the trick.

Speed Huts customer service was very good.

Where did you put the antenna?

[e015475]

Right now it is just stuck to the top of my dash above the radio.

I'm going to try and put it under the bed wood and see if the signal attenuation is ok,

If that doesn't work, I think I'll mount it on the bumper apron somewhere where there's line of sight to satellites.

[leegreen]

Is anyone running EFI with a GPS speedo signal as input? Does the GPS signal work reliably for slow speeds or does it mess up the idle?

[Black_Sheep]

Originally Posted by TX3100Guy

Where did you put the antenna?

I stuck the antenna to the inside of the windshield with 2 sided tape.