My speedo is off and All the ideas that are given to me dont work.So how do you fix a speedo thats off?

I have the stock rear out of a 98 ta,t56 out of a 93 and the cars a 95.

 

You can get it changed with a PCM tune from MadZ28

 

I have tried that its still off.

 

The only way to change it is with a program. You need to make sure they compensate for the rear-end gears, as well as the correct number of pulses from the tranny's sensor.

 

T56 has no pulses...

Did you let the tuner know what the transmission ratios and rear end ratios were before the tune was done? The 93 has a different internal gear ratio than the 95 would have.

 

Transmission ratios will not affect the speedo. Only the rear axle ratio and tire diameter.

The problem may be the 93 T56 VSS output. Its not the same as the 94 and later VSS setups. You might need to go to something like the Dakota Digital speedo converter box. The 94 and later PCM's are looking for a 17-tooth pulse signal from the M6 VSS. I don't know what the output signal of the 93 versions of the T56 might be.

 

I put White face gauges in my camaro and to do this i have to take the needles off. After i switched the gauges i put the needles back on. I have drove by those police radar machine that tell you your speed and I am like 4-6 MPH off. How would you fix that with a program? I'm pretty sure all my gauges, Tach, Speed, voltage, fuel, engine temp, oil pressure, are all a little off from what they really are, How can I Fix this besides just guessing where the needle goes????

 

Uhm, yes it does... the hall-effect sensor which is mounted on the tail-shaft picks up on a reluctor ring which is mounted on the mainshaft. As the ring rotates the hall effect sensor creates a pulse which is picked up by the PCM and used to calculate vehicle speed in coordination with the tire size and rear end ratio.

 

So in that case its not the tranny is the rear gears.So if the speedos off to the point where in doinf 20 on the speedo im going 30 would that make it 2.73s or 3.73s im not sure.

 

i have the same problem and from what i was told was it is becouse of the 93 trans i had madz28 do the tune speedo is still off i have talked to him and we are going to get it fixed on the next tune contact him tell him what yours says at 30 and at 60 and the exact gearing you have in the rear i belive he will get it right

 

cool thanks man

 

You might want to look at the "JagsThatRun" website. They have interfaced virtually anything, and have extensive information on the T56 reluctor setups. They note for instance that the 93 T56 with the 3.35 1st gear has a unique 11 tooth reluctor wheel, compared to 17 teeth on all other trannies. Is it possible you are using a 3.35 1st gear T56?

In this article on VSS sensors, at the very end, they show how to mount a toothed wheel on the pinion shaft to generate the pulse pattern you need:

http://www.jagsthatrun.com/V8-chapte...ed-Sensors.pdf

 

so would it be better to let ion reprogram it if he can or put a new ring in my tranny.I happen to have the old tranny so i have all the parts.