Hello all,


I've done some searching and finding quite a bit on recalibrating the speedo using different methods (eg. prom burn, dakota box, etc.) and was successful once I swapped my T56 in, I was able to get everything working.

My question has to do with once I swapped the rear gears my speedo obviously reads too fast. I recently got the dakota box hoping that the tuning availability would allow me to get the speedo to read correctly which I have not been able correct.

Can I, using a combination of the dakota box and/or the parameters in prom burning get the speedo to read correctly.

I'm running the T56 with 373 rear gears. Originally was the 700R4 with 323.
Using TunerPro for prom editting and burning.

Any help is greatly appreciated!!

Thanks,
Kyle

 

i take it your using a 7730 ECM.
yes, in TunerPro under constants & depending on which XDF you use, look for vehicle speed sensor or VSS gear ratio. you may not be able to get it dead on, but you can get it close.
i like using 1227730_8d for the VSS setting because it uses numbers from 0 to 255 & is easier to set for me.
i don't know which way you would need to go, there is a formula to calculate what you need to set it to but i can't find the link, or you can take a guess & change it & see if your going in the right direction.

 

No, you cannot properly calibrate for rear-gear changes with the 7730. You must use speedo gears in the tranny.

For the swap to a T56 which is a MAJOR CHANGE, there is a bit switch that will account for that. But, it is not "exact enough" to adjust for a rear-gear change.

 

The best the 7730 can do is a T56 and 3.42 gears. You'll need the Dakota converter box for 3.73 gears.

 

Why is that? Due to being cable driven or ECM/Buffer Driven?
Can you explain yourstatement so I can understand the problem better.
I may be going that route somedayand would like to know the whole story. Many posts touch on it but none explain the actual problem well.
TIA

 

Grim is right, i keep forgetting my VSS setup is different from a third gen & what works on my car won't work with the factory VSS.

 

Its ECM driven. The ECM can only convert 3.42 and numerically lower gear ratios from a T56.

 

Hey Kevin91Z and everyone else,

I have the Dakota box and unless I'm missing something I can't get the speedo anywhere closer then about 20-25 KMH (I'm in Canada) off.


I haven't had much of a chance to play around with the Instrument Panel Divisor that TunerPro has, but I imagine that between the divisor and the box I should be able to narrower that down...??

Thanks,

Kyle