Help with understanding "Req. Fuel" vs. impact on VE

[Targa44]

I acquired a used MS3 3.0 with all the hardware and parts about a year ago... from someone with an identical engine. Long story short, my engine on a test stand ran impressively (good idle, good throttle response - snappy) after hooking up the MS3. Then, when I bought my version of TS, I didn't know to save that current file. Since the orig. conversion, I've been very slowly hacking away at it with "okay" success - haven't currently incorporated AE yet.

I thought the original file was lost, but recently found (I think). It was saved under a "Prefirmware update..." file. Apparently the system saved it that way when I updated. I've looked it over and it must be what was in the controller when I bought it. There are some radical differences between that file and what I've developed. My main concern and curiosity is about how different the settings are. Primarily, I think the prior setting-up was wrong. The Required Fuel was at 15.6, but based on 21 lb. injectors. I'm certain that I have 30 lb - based on the stamping on the side of the injectors. So, they set it up with 15.6 required fuel and my input shows it should be 11.0. I think the impact of the prior setting was just stuffing a lot of fuel into the system and causing their VE table to show relatively small numbers. The prior tune doesn't hit an VE of 80 until up into the 80% kpa range at 5000 rpm for example. However, mine (while going through VEAL) with an easy as I can throttle hit a VE of 80 at 35 kpa around 4000 rpm. Note: our AFR tables aren't radically different. I seem to be hitting some rather high VEs much earlier than many of the others I've seen around.

Q - Is there more than 1 way to skin a cat? Does it matter very much where the VE table starts creating bigger numbers as long as you adjust other parts of the overall equation? So, ultimately, with AE incorporated to accommodate whatever the AFR/VE/IGN combination is - will come out with a workable solution?

I'm not sure if this makes any sense, but I'll start by throwing it out there. Please add any comments based on questions I should be asking.

thanks again,

kj

[billr]

"Q - Is there more than 1 way to skin a cat? Does it matter very much where the VE table starts creating bigger numbers as long as you adjust other parts of the overall equation? So, ultimately, with AE incorporated to accommodate whatever the AFR/VE/IGN combination is - will come out with a workable solution?"

Sure, you can use bogus values for req_fuel, as well as spark timing reference, and make an engine run well. The disadvantage, though, is that other tables/parameters will have to be "faked" to compensate for the req_fuel or spark being not correct. It will be hard to make sense of your tune, to compare it to logical (and common) engine operation; it will be hard to help you any.

That said... It is pretty easy to load that "found" tune and try it. No joy? Just load your present tune back in. Do be very careful to have each safely stored elsewhere on your computer.

[Targa44]

Thanks Bill,

... I do appreciate your willingness to provide input and common sense. I've thought about just trying that file, but I'm pretty sure I'm on the right track and have a 'reasonable' AFR table (while not "fat", a little on the rich side). As a side note, that other file showed how they set up the 2nd "baro" that I have... next steps are to incorporate certain portions of that file to test.

I haven't forgotten that I now owe you about 14 cheeseburgers.

thanks,

kj