Speedo Calibration
#1
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Car: Z28
Engine: 350 L98
Transmission: T56
Speedo Calibration
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
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
#2
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.
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
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Car: 91 GTA, 91 Formula, 89 TTA
Engine: all 225+ RWHP
Transmission: all OD
Axle/Gears: Always the good ones
NEw style t-56 = 40k per mile
Old style like ours were originally equipped = 4k per mile.
later
Jeremy
Old style like ours were originally equipped = 4k per mile.
later
Jeremy
#4
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Car: Z28
Engine: 350 L98
Transmission: T56
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
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
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Car: 91 GTA, 91 Formula, 89 TTA
Engine: all 225+ RWHP
Transmission: all OD
Axle/Gears: Always the good ones
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
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
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Car: El camino 70 ss
Engine: corvette lt1 94
Transmission: 4L60E
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