Speedo Out Due To Diff Change (VS)

[Wonky]

A friend of ours has a VS Calais V8 (electronic dash) which he has put a 4.11 diff in. Of course his speedo is now way out and he’s trying to find out how to make it correct. I assume there’ll be people on here who’ve done that in one in the past and can point him in the right direction. So far he’s been told that it needs the dash reprogramming but has found nobody who can do it.

It’s all foreign to me and I have NFI. :lol: I know on later models it's done through the ECM.

[Ryzz]

Back in the days when I had my VS GTS, I had it retuned by Dick from Dick's Electronics, and I THOUGHT you could change the ratio in the computer, but id by no means take that as gospel, it was 5 yrs ago!!!

[Rub]

Give holden a call... I'm sure they will "help" :stick:

[DaveHAT]

Gary,

Does Chev have access to Kalmaker tuning software?

Find a tuning workshop that has access to that and see if they can help you.

Or ... send Mark (aussie372) a PM. He changed ratios in his VT series I clubsport and runs a gadget/switch/box that corrects the speedo ppk to read correctly.

He might be able to help you.

[TommyVTss]

its not changeable in the psm as far as i know

when i got gears put in my vt ser 1 5 litre i was going to have to get a converter box and all kinds of crazy crap ,

so i just drove it like was,

tom

[VXSS346]

This is my experience from my old VP, if it helps.

I had to get a converter box, which attaches to the speed sensor, basically that just 'slows' the speedo down. That was back in 1998 though. :lol:
Cost me $300+ :(

Having said that, I got sick of it after a week because the torque converter locked up at 90km/h and I wanted it lower, (80km/h) so I just pulled the speedo apart, grabbed a small 1k pot, calibrated it with a multimeter before fitting it, (Old ratio divided by new ratio.)
In my case it was 3.08 / 3.45. So it worked out to about 880/120 ohms ratio on the pot. Fitted it and no probs at all still to this day. Its actually still very accurate. (the car is still in the family)

Crude I know, but works a treat. Now the torque converter locks up at 80km/h cause it thinks its doing 90km/h. :D

That's a really cheap way to do it, but the biggest disadvantage is the odometer is still too fast :( That works on frequency rather than voltage.
I gave up at that point :lol:

I would guess a VS V8 would be a very similar setup to a VP.

Cheers :)

[Wonky]

Thanks guys - gives him a better idea. :thumbsup: Sounds like it might have to be a converter box.

[Wonky]

Gary,

Does Chev have access to Kalmaker tuning software?

Find a tuning workshop that has access to that and see if they can help you.

Or ... send Mark (aussie372) a PM. He changed ratios in his VT series I clubsport and runs a gadget/switch/box that corrects the speedo ppk to read correctly.

He might be able to help you.

Thanks Dave - unfortunately no Kalmaker for Chev. Will see how my friend goes before annoying Mark. :)