Greenie LNF tuner

[BoostedYards86]

Doing alot of reading and not alot of LNF cars come to my shop. Mainly gm v8's and LSJ cars. I have a LNF I'm working on a tune for and have some questions. Mainly how to correct the maf to get rid of a lean spike at peak torque. Car put down some great numbers for running a cat and stock exhaust. Mods are as follows, hahn intake, hahn ic, hahn piping, hahn dp with cat and GM stage 1. Car made 396wtq and 313whp but like I said on tip in and up top maf is perfect just not at peak tq. I'm trying to make heads or tails of the ltft+stft maf tuning but i dont understand the language. these tables are foreign to me. Car spikes 25psi and holds 17.9 psi at redline. I'm reading alot of the info posted by term and byt and iam broke, but can't figure out why the lean spike is going on or what this purge solenoid is. Pics and explainations of what things like DAL etc mean would be super helpful.

[PopUpBlocker]

I have a LNF I'm working on a tune for and have some questions, I'm trying to make heads or tails of the ltft+stft maf tuning but i dont understand the language, these tables are foreign to me, what this purge solenoid is, Pics and explainations of what things like DAL etc mean would be super helpful.

I really hope you like DVD's. Buy Gregs. Helps fill in the parts that automotive tech schools leave out.

[Iam Broke]

DAL is desired air load. The setpoint for your boost and the basis for most of the LNF control.

Your lean spike is most likely due to the ECU ignoring the wideband when you nail it. Once the airload exceeds a certain point (around 240-260% iirc) you will see the STFT's go to zero even though the commanded lambda and actual lambda don't match. The solution is to work the MAF correction table in the highest load column to get the actual lambda in line.

Different beast to tune than LS1's. lol.

[laser_racer]

I really hope you like DVD's. Buy Gregs. Helps fill in the parts that automotive tech schools leave out.

Don't know how much that dvd will help on a lnf. You should look one of those tunes over and then watch that dvd.

[BoostedYards86]

I really hope you like DVD's. Buy Gregs. Helps fill in the parts that automotive tech schools leave out.

I have the dvd, and I didn't go to any automotive tech school. Self taught and proud of it. Don't know everything but there is always sufficient help online to help me along.

[BoostedYards86]

DAL is desired air load. The setpoint for your boost and the basis for most of the LNF control.

Your lean spike is most likely due to the ECU ignoring the wideband when you nail it. Once the airload exceeds a certain point (around 240-260% iirc) you will see the STFT's go to zero even though the commanded lambda and actual lambda don't match. The solution is to work the MAF correction table in the highest load column to get the actual lambda in line.

Different beast to tune than LS1's. lol.

Ok that makes complete sense actually. I am seeing exactly that happening and the maf correction should help. I will try this.

[Iam Broke]

Glad to help.

[BoostedYards86]

guys thanks for all the tips pointers and free information on here. this lnf was the first one that i tuned myself and the numbers were pretty good. I didn't even play with the cam timing at all because the car already slips 4th hard on the dyno and on the street. dyno was done in third gear and has full bolt ons minus exhaust...it still has the STOCK EXHAUST! with a cat too!

[Iam Broke]

Time to go catless and get a clutch.