I had downloaded a bunch of Y and F body bins from Gearhead-EFI forum and was curious to see what differences in AE fueling there were between the various models. For the most part, they're largely the same.

Some of the delta-TPS AE tables are very different in the higher delta-TPS values, as well as delta-TPS vs coolant. But most of the other stuff only varies marginally.

Any rate, anyone looking to utilize the 4th gen LT1 AE tables on a 90-91 (say, with a short runner Miniram or Stealthram)... this should be helpful (I hope).

 

I’ve mentioned the “other benefits” previously, but let me clarify.

I’ve tuned a lot of different vehicles, but tuned motorcycles more than anything else. Tuning by examining/reviewing OEM strategies is a good way to Get things in the ballpark. However, many of the strategies are actually a work around for the problems created by emissions goals and gas mileage goals… and others are working around patents for other ECU strategies.

For example, many motorcycles up until even the year 2011 use what’s called an AlphaN strategy… which may not even need any AE. This is simply when the two main parameters are RPM and throttle position. Keep in mind that smooth throttle reaction/connection are especially important on a motorcycle. So then as regulations tightened up, the calibrations created a lot of issues, and the solutions were adding secondary throttle blades, or MAP based tables that switched between MAP and AlphaN. Eventually TBW added to the mix.

Reason I mention this, is that it shows to me it’s best to start with a peak performance/behavior VE table and Ignition table, and then use AE as needed. What this means in other terms, is that for example 14.5 or leaner AFR is crisp, jumpy, jerky behavior, having 13.4-13.8 AFR is where it may really smooth out. Depends on the engine characteristics, but the more “highly tuned” an engine is (agressive cams and high compression, unrestricted/tuned intake and exhaust) the more this is a factor. So I think it’s best to start with a smooth AFR strategy, then apply the proper low power spark strategy, then apply proper AE strategy.

if you can, don’t just work on the AE.

Not recommending a change to a pure AlphaN strategy, because you would have to start from scratch as your own calibration engineer, but let that be a perspective to guide your tuning. BTW I have a 2008 BMW M5 with a 12:1 compression 5.0L V10 engine and an ESS supercharger on top, and it’s running AlphaN (no MAF no MAP tables, just MAP trims and temp trims). OEM it was MAF strategy with throttle by wire for the 10 individual throttle bodies. It does have AE but it’s minimal, and actually pulls a bit of spark timing for quick throttle applications.

To improve the AE situation with the MiniRam, an aftermarket system is very helpful with what I described, as you can easily adjust AFR targets for low throttle and that helps with a smooth tip in more than any AE strategy as the AE has some lag between when the throttle opens and when the fuel reaches the combustion chamber.