for those looking to adapt a tach into a truck

[towcat]

bob 442 showed up with this doohickey at dinner this evening.
It's made by Dakota Digital and it uses a bosch pickup magnet and their own translator box. In short, this will allow you to hook up a gasser tach to your diesel.
I'll let the pics to the talking.
Now I have to find a Snap-On Modus(sp) and compare the waveforms between the bosch pickup and the Ford pickup
a little history about Dakota Digital....
Years ago when Buick GN's were really hot, DD had a electro luminescent display that dropped in where the sucky stocker dash went. Good idea but really bad on reliability and when they burned out, it cost major $$$$ to repair.
They've gotten better over the years and from what I understand, this product is pretty bulletproof. I haven't considered them for a long time due to their notorious past, but this is worth a closer look.

 

[Ironman03R]

Anyone know what the factory ford gasser tach uses for a signal? Would this be able to be used on one of those?

 

[towcat]

Anyone know what the factory ford gasser tach uses for a signal? Would this be able to be used on one of those?

just got it confirmed this evening. this adapter has a high and low voltage signal output. You can run any tach. once dialed in, it's accurate, but the response time is not as crisp as a more expensive spark ignition tach. Those looking at using a tach for shift points will want to think about shifting sooner than what the tach reads out. Here's some pics of bob's install.
btw....the sensor is one off a ford IDI. The bosch sensor that came with the kit comitted suicide by throwing itself into the oncoming teeth of the thm400 flexplate. from what I understand, the waveform of the two is the same. the translator box sorts out the tooth count of ANY gear by the dip switch combination. If this unit holds up, my faith has been restored in dakota digital...

 

[seawalkersee]

So...how do you adapt this to a Ford factory dash tach?

SWS

 

[towcat]

So...how do you adapt this to a Ford factory dash tach?

SWS

if you have oem imputs, you don't need this.
if you don't and need an alternative, this will allow you to use just about any kind of tach on your diesel. but do bear in mind there are limitations, the response is a little sluggish.

 

[subway]

so what kind of cost is a doohicky like this?

 

[Agnem]

Just some technical background for those of you who are interested. Our factory tach's work like this. The sensor consists of a magnet, with hundreds of windings of a fine wire around it. When a gear tooth passes past the end of the magnet, the magnetic field around the magnet momentarily collapses. This induces a voltage pulse into the windings. The current and amplitude produced by this is very small, but can be seen with an ocilloscope. The output of the sensor is basically then a weak power source that is turning on and off rapidly. The tachometer circuit is essentially a pulse counter, which produces an averaged DC voltage as it's output. The faster the pulses come in, the higher the amplitude of the output signal, which goes directly to the tach-O' "meter" which is really just a voltmeter. All of these things of course, being tuned to work with one another. The only difference between a gas tach, and a diesel tach, is a gas tach usually is connected to the coil, and has to have a lot of pulse shaping circuitry to clean up and reduce the incoming signal to a TTL or CMOS logic level. So you could really say a diesel tach, is a gas tach with less stuff in it. This device which Towcat is showing us, is a programmable version of the pulse counter element.

 

[towcat]

so what kind of cost is a doohicky like this?

iirc $128 plus ship.
custom sensor brackets are up to you

 

[seawalkersee]

So, what do I need to take out of my gasser tach to make it work with the IDI signal from the gear cover?

SWS

 

[seawalkersee]

Just bumping this from over a year ago. Trying to find an alternative to finding the elusive diesel tach. Apparently the one that tow cat showed early in the thread has a signal pickup sensor with it. Apparently ebay has the adapter that you can use with the alternator and no input sensor for about $70 bux. I have not used any of these products yet, but I want to have a tach sooooooooooo bad.

SWS

 

[opusd2]

I just checked Dakota Digital's website and they seem to have a plethora of options to solve the problem of an aftermarket setup, maybe help with an OEM conversion.

 

[towcat]

the difference with the alternator vs. dakota digital is the versatility of tach choices. the alternator style restricts you to certain brands/models whereas the dakota digital will allow you to run whatever tach.

 

[towcat]

So, what do I need to take out of my gasser tach to make it work with the IDI signal from the gear cover?

SWS

i have determined the dakota digital interface will work with the the ford OEM sensor. As a result all you will need is the interface and a gasser tach of your desire.
so as a result, if you have a E-series van, you can now do a mod and have a real tach. the same goes with early chevy diesel pickup. the pics in the third post show a "fantasy" tach that never existed for GM diesel unless you had a bug up your ass to have one custom made.

 

[seawalkersee]

Yeah, I have gone through the yards looking for the right tachs. I have one in the bronco out of a gasser, but that I guess is the problem. I want to get the interface that will make it work, but I am not even sure if my factory sensor works. Even if it does, it is leaking back through the wires so it will not last long.

SWS

 

[Pino2234]

i have determined the dakota digital interface will work with the the ford OEM sensor. As a result all you will need is the interface and a gasser tach of your desire.
so as a result, if you have a E-series van, you can now do a mod and have a real tach. the same goes with early chevy diesel pickup. the pics in the third post show a "fantasy" tach that never existed for GM diesel unless you had a bug up your ass to have one custom made.

So Towcat, this Dakota Digital DSL-1 will fit in place of the Factory 7.3/6.9 IDI Tach Sensor?

I have an 85 & and 86 F350 and I am wanting a better tachometer. I was told I have to drill a hole so this can read from the flywheel.

Also this DSL-1 or DSL-2 needs to read more than 32 teeth. If this does fit in place of the factory sensor, is our injection pump gear more than 32 teeth?