John at 1320 is the best! I used his stuff and Moates to reburn the chip on my 1995 G30 Van after the ramjet cam and vortec head swap. A few notes, Tunerpro is sort of free and sort of community base. In some of the logging files there are mistakes, sometimes very bad. So if something looks out of wack it could be your car or it could be the buggy software. No one fixes the stuff as no one is getting paid to do so. GM never released the source code to the public. Everything is based on reverse engineering and a wild ass guess. So yes some stuff is not accurate.
You can pick up tunes off the internet. Most of them are hacked so bad they are not worth using. You are better off starting from stock and knowing that the engineers had a better idea of what was going on than a keyboard hacker that thinks big numbers are better. I lost power on the dyno when i picked up some of the timing tables to try on my chassis dyno and picked up a lot of spark knock when towing. Lots of other mistakes the tunes too.
The fun thing is to read chips from manufactures like Jet or TBI Chips and see what a huge rip off they are. I have some if anyone wants to take a peek. You have a compare function in tuner pro and you can pick the modified file and the stock file to see exactly what they changed. Snake oil and and a few degrees of timing. Some of the changes are useless as the did not change the rev limiter but most of the timing changes are above that point.
Last edited by Don_F; August 27th 2019 11:55 am.
Re: GM OBD 1 USB Adapter Demo
#751947 August 27th 2019 12:07 pmAugust 27th 2019 12:07 pm
Yes accuracy isn't guaranteed, the 95/94 5.7 file seems pretty accurate for most of the important readings at least enough to tell nothing's way off.
Although on the Safari van I'm working on the file that was specified for the 92-94 l35 was really only for the 92 l35 and I had to use the file specified for the 94 c/k 4.3 on the tuner pro site, Johns file he sent over email had the same file but it included l35 in the name, and it seemed fairly accurate after testing it, but it would be harder to tell if you're starting with a van with a major issue unless others with same engine verified the file is accurate.
1995 Emerald Green Chevy G20 350TBI Gladiator conversion
Re: GM OBD 1 USB Adapter Demo
#751977 August 28th 2019 7:42 amAugust 28th 2019 7:42 am
I used the 1995 file. If you never burn a chip you cant do much harm. Like I said GM never gave source the codes to the public. Everything has been reverse engineered, and not by factory professionals. There is a lot of mistakes in the 1995 files. Some of it is things you do not see, some of it you can. If you log the timing advance you will most like see numbers like 284834 degrees advance. Its a condition when the timing goes to retard the numbers get all wacko. The columns in the fuel log tables have extra data points. If you copy that data into the chip you can mess up the fuel tables a little too. I took it out on my version. Thats the thing anyone can make changes the release it and people grab it up without qualifying the changes.Trans pressure tables have mistakes and you can shorten your transmission life if you change the wrong one, so I stayed away from altering the pressure tables.The shift point tables do work well. It is the best software we have for 1987-1995 GM but it doesn't mean its good. Ha ha.