PPK value not changing anything

[darky82]

I just installed a 3.74 ratio diff and I have changed the ratio in tuner pro and started playing with the PPK value to get the speedo correct
Starting value was 62229 and I'm now at 90530 and it's making no change.

[antus]

You didnt say what sort of car it was, but check if the speedo gets it speed from the computer or not. its probably changing the computers idea of speed only, not the cluster. So still worth it so the PCM functions properly, but maybe not the whole story.

[darky82]

Sorry mate it's a vx commodore v8
So I'm guessing it's only pcm speed it's changing?
Just wondering than why a higher value didn't throw out everything with shift points

[antus]

In a lot of pcms shift points is more RPM based. If your at the top of the gear, move to the next gear. Not road speed. Wouldn't do any good if you put smaller diameter wheels on by accident (or purpose) and suddenly the car was limmi-bashing and couldnt get road speed up enough to change gear based on road speed. Or VSS fails and cant get out of first. Crank angle sensor for RPM fails, your screwed anyway as you cant run the timing or injection, but can have tolerance of a failed VSS or other mechanical faults or mismatches and get home with gears working and engine rpm within tolerances.

Speed limiter, swapping to idle tables, coming out of idle transients, enrichment, enleanment, fast enough to have enough airflow to not engage the fan, torque converter lockup - those types of things are more often speed based.

[darky82]

Thanks for the info makes more sense now with how it works
So i need to get the speedo right in the pcm and than use the body diag software with the ppk value from the tune for the cluster?

[antus]

I havn't done it so I cant say for 100% but that is what I would be looking to do and what I would expect to work.

[darky82]

Thanks antus
Yeah the PPK value is made even higher 9800 and I'm still at 60kmh in tuner pro dash 60kmh on the speedo and 48-50 gps
Should it even need to go that high a PPK value?

[antus]

If you're changing PPK and not able to observe results your doing something wrong. Maybe a bad or mismatched XDF and your changing the wrong thing in the bin, maybe a bad or mismatched ADX.

[darky82]

OK I will have a poke around at some other xdf and adx files
How come there is no lists on the site for LS1 bins and tuner pro files like there is for v6?
I was just reading on another post that changing the PPK value will throw out alot of other things and it's best just to leave it alone as it will throw out other things
Some of my shift tables are speed based so I don't know if just adding 11kmh on to them will do the trick
Really don't know how to go about this anymore
Speedo is corrected but I can't really do any decent pulls yet because the diff place said I need to wear the gears in

[antus]

Because LS1 is next level compliated. I figured out how to reflash them, but defining all the available operating systems I left up to others. There are threads that cover the main operating systems, but nobody has stepped up and donated skills and time to find, test and maintain a high quality repository of files. There have been a couple of attempts but nobody has stuck at it and kept building. So, its piecemeal. You need to look at your OS, search for XDF. If you cant find a quality one then you might be on an obscure operating system, and there might be a more common one which you are best off swapping to, then use an XDF for that. There are a couple of well known most common operating systems that are the best defined. There is also universal patcher, which searches for patterns to find things, rather than using absolute values for the operating system. I got in to this because I put a VP/VP '808 on my gemini, and I have a large number of Aussie and American P01, P04, P05, P10, P12, P59, E54, 4 connector Black box, E54, earlier generation Australian PCMs on my bench, but other than the '808 none of them are in cars and none of them I am actively tuning myself. I am just making sure I can read and write them and then I leave the rest up to others. That and the forums is as much time as I am prepared to put in to this hobby and give away for free. Hopefully one of the people here because they are tuneing these cars can give you better advice. I would suggest you look in to what commodore has the same diff as you put in (HSV?) and search for a bin that had that configuration and check what it has for PPK, speed settings and trans settings. Best way to learn is to start with looking at what the factory engineers did.