I have my VE tables pretty well locked in and now am working on WOT AFR. Before I lay down money for dyno time, I’m using on-ramps to determine where I stand on WOT AFR. Using a ZT-2 WB that I have had for quite some time. Overall, I am shooting for 12.8AFR and may use dyno to get to 13.1 which previously has shown an increase in peak HP of about another 12rwhp. So my methodology is to get on a fairly safe and long on-ramp and stomping on pedal in 2nd gear to 7500rpm(LT5). The area I am trying to adress, if possible is the AE pumpshot on initial hit. I’d like to get it so it takes me from stoich and leaves me at 12.8-13.1 as PE takes over. Any suggestions on where to modify the pumpshot. I have been using the AE delta MAP table. The LT5 does not have delta TPS% table as other small blocks have. Altho there is a PE table, I basically tune WOT using High Open Port table. Also benn playnf w AE Decay Factor.

Any suggestions?

 

What AE parameters do you have?

Decay factor is a good one to play with... I know on my Miniram, you don't want the AE delta-MAP to linger around too long. I actually bumped it from the factory 40% to 60%. For whatever reason, the delta-MAP AE (if excessive) can cause a laggy feel to the throttle (as felt from the driver seat).

On a full throttle mash, what I notice now is a very fast (like less than 1/2 second) drop to ~11:1-ish, which then recovers to my PE AFR of around 12.5:1. With the factory decay settings, it would linger around 11:1 (even dip into the 10's)... and you could feel the rich condition clear when the acceleration picked back up.

Another possibility is to reduce the AE value at the highest delta-MAPs. The theory being, on a slower application of the throttle, you may actually get repeated shots of a lower delta-MAP AE fueling...(i.e., the ECM considering it a series of smaller delta-MAPs) whereas on a very fast mash of the throttle, you're into the higher delta-MAP areas of the table.

In post #11 of this thread, I offer my thoughts on AE fueling for 6E based on my experience with 8D. Not sure how many of those are applicable to you...

https://www.thirdgen.org/forums/diy-...injectors.html

 

On my .xdf, I have reduced Decay Factor to 0, which is what stock is set up for. That appeared to shorten the pulse but still enough to have AFR drop to 11:1, but for a shorter period, b4 recovering to the desired 12.8-13. Since AE is a function of the VE table, I’m also playing w the VE values in the cells where AE initiates.

 

I've never heard of that before. Is that particular to your xdf?

On 8D, delta MAP AE is provided on synchronous fueling, but it's not related to VE tables as far as I know.

 

The problem with using your VE table to smudge AE is you end up with a rich condition when you are at those values while not needing the additional AE pulses. It inherently contributes VE, but you want to limit how much it does.

I would think in a perfect world/theory you would nail down your VE tables with zero AE or adders on a engine dyno/load simulator and then use the AE/DE/PE etc adders to assist in drivability issues.

In a non-perfect world you can't effectively do that. So you try to drive softly to avoid AE as much as possible as you get your VE tables dialed in. Then start dialing in AE and other adders. Once those are close/dialed you do more VE table tuning to make up for the changes in adders have made.

 

Was just looking at the two LT5 XDF's, not much you can do with the AE Dom other than trying to time it in correlation with the PE which seems a little more precise. Then just dial it in with your wideband feedback when reviewing...

- Rob