I am new to this forum. I hope I am posting this in the right place. I own a 4th gen camaro, but this is about a 1994 chevy full size blazer with a 350TBI 4L60E tranny. Everytime I have searched for info on tuning, has turned up with this site in search results. Very, very good info and some intelligent people on here, who know way more than I do. So I am here for help. Hope I dont get any flack for not owning a 3rd gen, but I just couldn't resist signing up. I just recently rebuilt this 350 in said blazer with only a cam upgrade. Its a compucam. Cam Style Hydraulic flat tappet Basic Operating RPM Range 1,200-4,800 Intake Duration at 050 inch Lift 204 Exhaust Duration at 050 inch Lift 214 Advertised Intake Duration 264 Advertised Exhaust Duration 274 Intake Valve Lift with Factory Rocker Arm Ratio 0.423 in. Exhaust Valve Lift with Factory Rocker Arm Ratio 0.446 in. I also recently ordered a burn2, some chips, and adapters to start tuning. Ive burned two chips so far. I am totally new to this tuning thing. I have made small changes, such as raise the idle to 600, no suprise that the tach is off by almost 100rpm. I would like to know what table to use to richen or lean the mixture throughout the rpm range. I only see to things in tunercat that has to do with a fuel table really and thats the main fuel table off idle %VE and Main fuel table near idle %VE. So if I increase the Percentages in whichever cell it richens the mixture right?? and Vice versu. I have already adjusted the timing tables not by much really and have a seat of the pants difference. I have a wideband installed, and at wide open throttle its running 13.5 and it's not steady it moves up and down a couple digits. When it's shifting it spikes lean. Is that normal? It jumps to 15.-16. After the timing change it's a little snappier and quicker acceleration, but thats to be expected. Im making small, small changes. I have no way to data log. I plan on getting an ostrich emulator, and a cable to data log in the future. Were do I go from here, can I richin the mixture through the two main VE tables, Im concerned about richening the mixture at WOT only at this point. Is 13.5 ok at WOT. I think more power could be at 12.6-13 range am i correct. Any help on how to tune this thing would be appreciated, suggestions or comments at all. Its a $0D definition file, 16196395 PCM im using tunercat.

Does anyone know how to convert KPA into Hg' vacuum readings? I think that the higher the KPA value = less vacuum?

Yes, 100kPa = no vacuum.

Head over to the DIY-Prom board and read teh stickies. Theres a lot of good info there, as well as a thread on how the VE table works.

As far as the VE tables. There is one table for the engine idling + throttle closed, and one there for when the throttle is open. Put simply, this is because there are two spark tables (idle/throttle open), so the VE will be different when a different SA table is used at idle. So, each spark table has a matching VE table. The TC definitions seem a bit ambiguous.

As far as datalogging, you can use tunerpro RT and an OBD-I cable + ALDL converter, which can be purchased from moates.net.

Ok will do, I read the "Come in for a free tune" article, great information there. Just had to read it a few times, to understand some of it being a newby tuner. So with in those two VE tables I can just increase the numbers to richen up the mixture, and decrease them to lean it out?

"In conclusion, to make a long story short, if you raise a given value in one of the VE tables you will be increasing the amount of fuel the engine receives at that given RPM and that given MAP".


Bingo! found the answer in a sticky