Where's the best place in Tunercat to tune your A/F ratio. Currently I have it faked out by cutting down my injector constant to richen things up. Is this ok to leave like it is, or should I adjust elsewhere? My BLM's were showing lean and after I cut the injector constant down from 24 to 22 at the track, I shaved an instant 2 tenths of my ET, so I know once I got things richer, it ran better. Would like to know cause i'm heading out to the dyno next week, so I want to get some programs ready. Thanks.
Ken R. 95Z

 

Injector constant is across the board, and closed loop operation will simply change your BLMs as best it can to fix what you did.

Either change your VE tables for low TPS operation or fix your WOT tables vs temp and RPM for WOT.

 

Dr. Mudge, are you suggesting that the VE tables actually do something in closed loop with a functional maf?

 

Dan, I would have to say that VE table changes definitly affect closed loop MAF tunes. I ran my program through VEmaster and it improved my drivability dramatically and brought my BLM's which were high and split back in check. It does work. It was nice because my car has never run that smooth in closed loop since before my heads and cam. And Dr Mudge, Yes, you are correct on the across the board change with the injector constant. I'm thinking about leaving it as is because that also improved my BLM's and brought them just below 128. VE master pretty much took care of the split and brought them down closer to 128, but it was the injector constant that pushed them just below 128 which is now letting it lock in at 128 on my WOT runs at the track and also got rid of my knock retard. After that change, I wasn't seeing any KR all the way up to 6375 rpm. I plan on adding some timing on the dyno to try and find where it starts kicking in. Aught to be interesting. Thanks for the input guys.
Ken R 95Z

 

Dan, I have no idea, it was always a hotly debated topic. Some say yes, some say no, I didn't notice much diff on my car when playing with VE tables, some people even wiped them out to zero - I ran an open loop tune, for several reasons.

 

A week or so ago I ran VEMaster on my car and it seems to run a little better. I haven't logged anything...just thought I'd screw with it a little.
I hope to be tuning a hotcam car this weekend for part throttle/drivability stuff only and want to run VEMaster on it and see what happens. It seems that in certain fuel trim cells we're getting blm's over 128 (pushing 150) and in others the blm's are between 120-128. The original program is from PCMforless and the VE tables in this file are not stock. I've also looked at an Ed Wright hotcam file and the VE tables in that are also changed. Funny thing is....pcmforless subtracted values from the ve tables and EW added to it. Strange. Both files are for the same combo too.

I will post any results for anyone interested.

 

I have used VE Master as well and it has given me good results on several cars. Yes, it is a hotly debated item whether it works or not or is it just intended for SD fuel back up incase of MAF failure. But from the results I have seen before and after in all cases it was a definite improvement.

I have also seen several Ed Wright and Formatto calibrations for various cam combos and they too have edited the VE tables as well. Formatto isn't a name that you see very much but I can tell you that he did 95% of all of LPE's tuning for them at one time. Jim was a genius at working on GM EFI calibrations for both the older removable prom and the later flash PCMs. Regretfully Jim passe away a little over a year ago.

Just my 2 bits worth, some will argue until they are blue in their faces over this subject but I have seen results personally and until its proven that it doesn't work I am going to continue to use it as a tool. I can't beleive that the only function for the VE tables is for fuel back up (limp mode home).

 

Someone e-mailed me a file that Formatto supposedly did for their 93 LT1. I just wanted to check it against a file that I had gotten from Ed Wright for the same car. Know what....the Formatto file was identical to a hypertech chip for said car. I'm trying to imply anything here....just thought that was really strange. BTW, the EW file was drastically different than Hypertech/Formatto file.
Did Jim ever work for Hypertech or something?

 

No I don't believe he every worked for HyperCrap. I don't know him personally, he did some tuning for me many moons ago on a supercharged 454 SS PU truck that I was involved with a 540 BB installation. He burned the chips for that set up using a 1227730 ECM. That truck would run 10.90's all day long using a ACCEL BB EFI manifold and injectors but we chose to use a GM ECM for fuel controls and save a bit of on the back end as far as cost goes.

The manifold was purchased at a swap meet for $500 including fuel rails and injectors, we scabbed in a TPI harness from a Y car and in the end it all looked like it came from the factory that way. Plus it drove like a kitten and got about 12 MPG which isn't bad for a 10.90 class PU that a 55 year female drove. Her husband died and left her with it unfinised, she had me help get it running as it was something special to her. I still see her from time to time and every time I see her I always remind her that I get first crack at that truck if she ever decides to sell it.

He also did some tuning for me on my 93 corvette which had a 383 in it which ran 11.10s on the motor, I don't have that car anymore otherwise I would pull the prom out and check it out as you did. I had HyperCrap do their thing and $350 later the car still ran like crap. I contacted LPE at that time and begged them to burn me a prom, seeing how I purchased all the parts from LPE they finally told me it was Jim that was doing their prom burning for their engine conversion packages, and gave me his phone number. Up until that time I never heard of Jim Formato and at that time Ed Wright wasn't around. At least I didn't know of him then.