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How to fix checksum VP V6

Posted: Fri Dec 17, 2021 1:41 pm
by Charlescrown
I'm playing around with a VP V6 bin file AWU9398 and need to know if I need to correct the checksum after changes have been made. If so how do I di it? I have though of using 12P but I do know the auto has an output to the inhibitor switch which I assume is for idle correction.

Re: How to fix checksum VP V6

Posted: Fri Dec 17, 2021 3:29 pm
by vlad01
I'd just use 12P, works fine with VN-VP autos. I used it temporally in my red VP before I did it up and converted it to manual.

Re: How to fix checksum VP V6

Posted: Fri Dec 17, 2021 4:02 pm
by Charlescrown
Yea I was thinking it would be fine. I'll look at swapping over the VE and ignition maps. Boy they were a mess from GM.

Re: How to fix checksum VP V6

Posted: Fri Dec 17, 2021 4:56 pm
by vlad01
The 12P stock VE table is very good for VN 2 and VP.

I used my tuned VR 12P map with pacemakers on my VP with pacemakers too and when retuning with the wideband there was 0 difference from the VR map despite having lower comp, only thing I did was add a certain percentage to the complete map until I got 2ยบ to the peak WOT timing for the VP for the lower comp.

I have noticed that VN 2 and early VP factory tunes were far more economical than the late VP tunes but I never actually compared them. Both my 93 VPs stock auto with low ks did around 10-12L/100km where as my early low k 92 VP auto did mid 7L/100km in similar cruising and light town conditions when filled at the pump. My red VP poured black smoke when WOT and I ruled out everything else causing it. Must of been in the factory tune.

You are better off using the stock 12P tables. I know VRs in good condition get good economy and those are the tables they used.

Re: How to fix checksum VP V6

Posted: Fri Dec 17, 2021 5:27 pm
by vlad01
Had a look at the newer and old VP factory tunes. Didn't see anything really different apart from a single cell mistake in the VE table of the tune you mentioned. So don't know why the later VPs use so much fuel compared to the older ones.

As for 12P vs the factory VP tunes there isn't a massive difference in the shape of the VE table, obviously the 12P one is a higher res and more precise so I would still use that over the factory VP stuff.

BLCD vs BAAM.PNG

Re: How to fix checksum VP V6

Posted: Fri Dec 17, 2021 9:14 pm
by antus
Yeah 12P works on all models VN-VP and VR manual out of the box with factory engine/trans combinations. There is also the APNX bin in the 12P zip for the series 1 which has quite different spark maps. The 1.5 and above all work well with the BLCD base for manual and auto and then you get the evolution of the code and maps GM made up to the VR for that engine, and then you have BLCF for the V8s.

Re: How to fix checksum VP V6

Posted: Sat Dec 18, 2021 7:43 am
by Charlescrown
Got me convinced. I'll go with 12P. Yea vlad that big hope at one point is a glairing error but with interpolation it probably didn't show up in the driving.