The ve and maf work together, when you tune maf you don't know if your error is 100% maf or the ve is scewing it. By tuning the ve first in sd mode when you enable the maf again you know the error is maf only.

Also like you are finding, multiply % by half or you will chase your tail.

 

Thanks.....

I also pulled a tune from the repository and compared their VE and MAF tables to mine.

MAF looked pretty close

VE looked entirely different - even the pro tune looked entirely different.

I think I might just get it as close as I can, clean up the problem area I'm having my dropping the PE Throttle percent down, and tuning for WOT with the PE table.

 

Went a little better tonight. Did the best I could. Still have a spot between 2500rpm and 3200rpm where the AFR goes to about 14.9AFR (target is 14.1 Stoich for E10 we have out here in AZ) I messed with the VE Tables to no end - no difference.

Everywhere else is great so I just made the PE come in sooner to drive around it. Found the sweet spot so it doesnt mess with part throttle cruise.

Also, I still have a lean tip in off idle. I messed with the VE table there as much as I could without feeling like I was really messing with the tune too much.

Under WOT i nail my AFR target till about 6000rpm then it goes rich by about .2 or .3, so me being lazy I just calculated the PE value to drop AFR that much and validated it and I'm pretty happy.

I'll still smoke test the intake to check for leaks but STFT's go steady at idle together, only under cruise are they different. They swing a little more than 5% positive and negative during cruise, but at idle they drop to around 0-1%

 

You won't get your VE table perfect. So much affects the table day in and day out. STFT's are contantly changing/swinging. It's not uncommon for it to swing +-4%, so with 5%, it's not terrible by any means.

The point is to get it close enough that what you command in the PE table, is what you see on your wideband.

You can leave the MAF off if you want. It's not going to make a huge difference either way. Some people say SD actually runs better, smoother, etc.

 

I love SD, but I am also running boost. If you tune the MAF right it will work great. The problem is that on the older PCM the MAF range is limited. The newer computers have much greater range. Fuel trims in the +-5 range are perfectly fine, stock vehicles aren't even remotely that close. I like -5 to 0 just to avoid positive trims being carried over to WO but again its personal preference.

 

You should do them completely separate. Even if your ve values are perfect, you don't know the amount of contribution to error from maf if ve is contributing to the charge estimation...unless you back calculated using the dynamic filter values which are not always available for calibration or viewing. Also that would be painstakingly tedious.

Ken, your lean tip in cannot be fixed using the ve table. It needs transient fueling adjustment which may or may not be available for calibration... But whatever you do, don't pay any attention to stft or wideband information during an rpm or map delta where the transient fueling model would be active. Even if any transient fueling calibration was accurate (they aren't) and you could actually comprehensively calibrate for transient fuel (you can't), the most robust method of dialing in ve values still involves ignoring fueling feedback during a transient.

Hpt and efi live are good, but they can't do everything. Ask me why I stopped calibrating for the aftermarket

 

I'm wondering if the Transient fueling is to blame for both the part throttle miss between 2500-3200 and the Lean tip in.

I was worried that the misfire could be timing related or my gap is too large on my plugs, but at the same time I'm thinking that because it fixes itself by lowering the AFR with PE then it cant be. I am running TR6 Iridium plugs if that matters?

 

Post up your tune and logs if you want any of us to view them and offer advise too if you want other eyes to look at it.

 

Why did you stop calibrating for the aftermarket?

 

Haha of all people, you know why...