VY Commodore Speedo reading half what it should - How to fix?

[evilstuie]

Hi All,

I'm having issues with my speedo.

I've got a small block chev 400 24x converted motor with a 0411PCM running the unified OS, and the logging software has the right speed, the transmission changes seems to be in line with the speeds as well, and the rpms are reading corrrect, but for some reason the speedo is only showing around half of the correct speed.

I've attached the tune to see if there's something obvious, or if there's something I need to change either with the tune settings, or if it requires the gauge to be changed.

For all the details, the gauge cluster is from a VYII V6 Holden Commodore, and I've also installed the BCM and PIM from a commodore as well.
I'm using a 4L60E transmission with electric pickup, 2.73 rear end with 225/60/15 tyres with a total tyre diameter of 26.5".

I just need to adjust the signal sent to the speedo without changing what the PCM speed is registering otherwise it'll start doing weird changes and kickbacks etc.

[lukearmstrong1990]

edit the sensor calibration "VSS pulses per" (km or mile).

"Trans revolutions per mile" is the value used to shift, log one speed PID and control converter lock up.

editing the "VSS Pulses per" value under sensor calibration will only effect the engine switching airflow and idle stratergies and the guage reading.

made a radical change like double the value aand flash it in. if the gauge responds youre in business. edit by adding or reducing a percentage. example. if youre doing 100kmh and the speedo records 110kmh the reduce add 10% (multiply by 1.1) and you'll be close.

I rarely get them right off of formula. I just use the dyno and calculate a percentage of error at 60 and 100kmh and edit as needed until is bang on. VSS pulse per will only change engine airflow and gauge, nothing to do with trans or converter managment