Correcting Speedo's?

[Jayme]

not a lot more no... just lean cruise and tcc lockup. neither of which really matter if set a bit lower. personally, id rather reset the tcc lockup and lean cruise enable than every shift point....

[VX L67 Getrag]

I believe there also some speed related spark table/scalars too!

not that I'm doubting you Jayme as I class you as 1 of the experienced tuners!

[TTVN]

if the ppk isnt changed the speed limiter will cut in early which isnt good if u race it

[VX L67 Getrag]

o.k. just found out he went to holden & got dash flashed with tech 2!

But they didn't fix it in the cal at 100kmh it's showing 114 in the PCM data so thats going to throw things out!

looking at the stock output speed shaft factor it's at AAAB which with calculation works out around 40!

So I'm guessing I need to change this by a bit over 10% but not sure which way?

I guess I can try both?

[TTVN]

interested to see what happens

[VX L67 Getrag]

o.k. well as it was was reading around 56kmh when was actully 50 so I changed the calculated value which was 40 to 35.8 & it then made pcm data read 62 so I then went to 44 & it went to 51 to 52 so I went to 45.1 & bingo spot on, now in theory all shift & speed assoc. tables should be right?

If anyone interested the calc for the ppk was: X*60/65536

Cheers VX L67 Getrag

[Jayme]

they were all in the right spot before you corrected the speed. now that you have corrected the speed, you will also need to correct all of the shift tables as it will shift at a higher rpm now. its easy enough to test... just drive it out ont he road and plant it and see if it hits the limiter.

[VX L67 Getrag]

I would love to test this!!!

so I have raised the rpm limiter for each gear are you talking about that or the speed limiter for each gear change?

as I just assumed if the data from pcm tells it that it's at 60 when actually 54 it will be changing wrong shift points?( I haven't got the logic to think outside box about what the wheels are doing in relation to this?) LOL

[Holden202T]

the issue is that all the shift tables for each gear are wanting to shift at say 64kms, but with the change in diff gears your motor will hit the rev limiter before it gets to 64kms, so you need to lower the numbers by the same percentage you changed the speedo.

[TTVN]

hed this conversation with d/w a while back and after changing ppk by the calculated % and changing the shift tables by the same % it was fine