crazyjim

So I'm building a ragged edged street car. Full aluminum dash, carbbed setup... NO computer and as LITTLE wiring as possible. Aftermarket column, doing away with vats, EVERYTHING is going except the bare essentials. My question is, can I run a T-56 with out using any of the electronics. I know my speedo won't work, but since I'm using autometer gauges I figured I'd do this;

I'll just run a single large tach in the middle of the drivers side dash and the rest of the neccesary gauges (fuel, oil press, volts, etc) As far as a speedo, for the price of an autometer speedo I could just throw some extra cash down for a G-tech or something of that nature and get true GPS speed. Any body see a problem with this?

sofakingdom

iTrader: (1)

The T-56 doesn't need a computer for anything.

As far as the speedo, that's up to you. GPS would work, as far as that goes. Not sure where a G-tech fits in though. Alternatively, you could use the T-56's pulse generator, and a Dakota Digital box, and an electronic speedo such as an Autometer. Might cost less than GPS, and would certainly be a faster responding setup.

crazyjim

See that's what I was referring to. I was reading a thread about some people having problems getting the dakota digital boxes working properly. Getting them calibrated too. After looking, I just found out the G-tech doesn't have a speedometer, which they should. IMO

Zepher

iTrader: (1)

All you need is a good memory and a tach. Use the GPS as a reference to get the speed and note your RPMs in that gear and you are good to go.

An Autometer speedo is very easy to setup with the T56, just mark a 2 mile stretch, put the speedo in calibration mode, drive the 2 miles and stop, press the calibration button and you are done. T56 puts out 4000 pulse/mile.

sofakingdom

iTrader: (1)

I don't think a T-56 puts out 4000 pulses per mile. It would be more like 40,000. IIRC the reluctor has 17 teeth; so that's 17 pulses per drive shaft revolution. Still, if that's within the range that the speedo can adjust itself too, it would work without the box, to turn it into 2000 or 400 pulses per mile.

The reason a G-tech can't possibly have a speedo, is because over the long term, it has no clue how fast it's going. It's an accelerometer. It measures the force placed on it that tends to accelerate it. So for a short time & distance, it's pretty darn accurate; but over a long time, even just a few minutes, any electronic drift in it, magnifies itself. Probably be OK in the city, if you re-zeroed it every time you stopped; wouldn't be worth a crap on the highway.

Ricktpi

You could run a GPS speedo like they use in powerboats. A Autometer progammable speedo should work.

Zepher

iTrader: (1)

I could be wrong, but when we were setting the Autometer speedo it went to 7980 in teh 2 miles on the ODO when we were setting it. it's been a few years since we did it and that might have been with the 4L60E.

sofakingdom

iTrader: (1)

Well I wasn't there, so I'll take your word for that.

However: with 27" tires, your car goes about 84.82" per tire rotation. Divide 1 mile, or 5280' by that, you come out with about 747 tire revolutions per mile. Multiply that by a typical street rear gear ratio, say 3.73, and you find that the drive shaft rotates about 2784 times per mile. Multiply that by what you see in the pic, call it 17 teeth for the sake of argument, you come out with about 47,330 pulses per mile.

I have no clue what the 4L60E speedo apparatus is. But, there you have the numbers for the T-56 one.

dab2pds

i was looking at these on jegs. this one runs about 200$. description below:

Speedometer, 200-MPH, In-Dash Mount
105-4490
This programmable speedos feature ''push-button calibration'' that can be easily set while driving. This makes changing gear ratio or tire size easier than ever. The LCD odometer is highly visible and retains the actual mileage after recalibration or in the event 12-volt power is removed, also includes a resettable trip odometer. Will work with late-model transmissions that have an electronic (500 to 400,000 pulse/mile sender) output. Requires sender 105-5291 or 105-5292, if using an early model (cable driven speedo style) transmission.