DracoZK

Before anything, yes I have searched.

I am looking to get my speedo correct by adjusting the VSS signal (4006.96) and the Divisor (TunerPro).

Last year I put in the T56, changing the Divisor to B5+B6 for it to read correctly on the speedo.
Now my issue is that with installing the 3.73 gears, my speedo obviously reads faster.

I've tried changing the VSS signal to a much higher rate, one member was saying that the T56 has a 17 pulse rate .... (????) haven't read anything else on that.

I've tried changing the Divisor to different rates. ie B7+B6 etc. If this is the case, then when B5+B6 are correct when running the T56 and 3.23, then I need it lower, but according to the tech article B4-0 are not used.

Seems like no matter what I do it still always reads that 15% higher then actual speed.

Am I missing something somewhere? If anyone can help me or guide to something else to try that would be appreciated.

Thanks,

Kyle

ty1295

I am not familiar with your application in particular, but do you have a DRAC box? (little white box)

I know in the ecm world I play with (mostly syty's) the drac really controls pulses to speedo/ecm. It is adjustable with jumper wires.

3.8TransAM

NEw style t-56 = 40k per mile

Old style like ours were originally equipped = 4k per mile.

later
Jeremy

DracoZK

3.8TransAm - I didn't see any difference in changing to 40k pulse

ty1295 - I remember reading a thread on this drac thing, I thought it was an additional part that you could install. Is it stock on certain cars? I recall something like 88-92 Trans Ams having the electronic speedos as well as the 90+ Z28, would these have the drac box?

I'm assuming this is under the dash not too far from the ECM..... on the passenger side?

Thanks,

Kyle

3.8TransAM

Yeppers.

Its a little yellow box.

Do some searching and check the links in the stickies.

Someone has a page somewhere describing what resistors etc u need to change to correct it.

Its out there, that I'm sure of, where I dont know.

later
Jeremy

honken

Digital Ration Adapter Controller Calibration

DRAC Calculator Page