Quote Originally Posted by donf View Post
I was told not to waist my time, but I was curious to see for myself.
I got a cheap Jet Stage 1 chip to look at used. Its for a 1995 350 4l60e so I put it in. My chip with only revised shift points in a few gears was much more noticeable when towing. So I compared it to the stock truck bin to see the difference.
Main Spark vs Map Table was bumped by 1.1-3.2 degrees. This is supposed to be for a stock engine, but a lot of the changes were at 4400-6000 so not even noticeable as the engine never runs that high.
They bumped the fuel cut off from 98 to 115 mph, the only way my van will ever see that, is if it falls off a cliff.
The main fuel table was increased in almost the same areas they bumped the timing. Probably to combat detonation by making the engine very rich.

I cant believe, companies get away with selling this for $150 and up. Mine cost almost nothing so it was almost worth it just for the education on what not to do.
I read a Hypertech I found in a 92 GM van once. For $2 at the wrecking yard. All they did is target a leaner PE mixture and increase the VE table and spark map in the 80+ KPA range. I tried it and WOT it actually ran very well but no changes to anything that would effect emmisions.