dynoing and the tach wire

[king D]

found a new dyno that hs just been installed close by and am going to put some time on it saturday,however the owner says i need toknow where the tach wire is so i can get torque numbers any body have a clue ?thanks in advance...jess

[8.1GASSER]

king D, I know up here in CT that we have been using an optical sensor with the dynojet. If memory serve me right tach wire should be at pcm and should be white or purple w/ white stripe, not sure on pin number though. A decent car audio shop that installs remote starters should have the answer to your question.

[DIESELMAX403]

kingD,

I wish I could help you on the tach signal, but I have been looking for one myself. I went to dyno my truck, but after spending 2 hours searching for a tach signal, I gave up. I tried this forum, performance houses and even another dyno shop and I could not find a signal.

The shop I went to has a dynojet and their system uses a pick-up probe similar to that of a timing light. This probe requires a considerable amount of current (i.e. spark plug wire)to trigger it. Clipping onto the computer wires will not work. There is not enough of current running through them. An optical pick-up will work, but the dyno shop must have the equipment integrated into their system.

If anyone out there knows a wire that will work with the current probe, please let me know.

Thanks

[sdaver]

place a piece of optical tape on the harmonic balencer or main crank pulley and use an optical sensor most dyno shops have them. You will have to remove the motor cover........Im not sure if a diesel has a harmonic balencer :D

[Max Power]

You can get it at the PCM, it is a white wire. You can also get it under the fuse box. Remove the metal bracket and the plastic cover. Below that you should see a black 20 wire connector. The tach wire is white.

You can check to see if you have the correct wire with a Digital Multi Meter (DMM) Set it to AC voltage, hook the black lead to ground and the red leat to the wire you want to test. The voltage should read between 1 and 5 volts and should increase with RPM.

Good luck.

[Burner]

-Jess, The voltage wire could work :rolleyes: but I think you would be better off doing it the old fashion way...err sort'a. Do like David said and stick the reflector tape, just remember to take the tape off. :eek: Yes, someone left the tape on and the readings were whacked...another piece of tape was added by mistake! Can you say 7,400 RPM "stock" Dmax? :D High flex or strong vibration can, but probably won't, throw off the optical sensor.


The "direct" approach (tape) gives a more "hands on" fell to it. ;)


Burner-----> :D

[sdaver]

:D