Stock ECU questions

[sleepydsm]

Concerning 91-94 awd 5 spd:
Can someone explain to me why exactly a stock ECU sucks once you get to the point of upgraded turbo and supporting mods? If I remember right it has something to do timing or airflow?

What kind of benefit would a burnt chip add?

This is kind of vague, I know.

For example, my car has:
20g, 650cc, maft, apex 5 knobber, etc.

[Jakey]

From what I understand (which could easily be wrong): the algorithms the stock ECU uses to "run" your engine based off of the OEM timing and fuel maps can not compensate for the increase in air and fuel you are seeing due to the modifications. By having a custom chip burnt, the timing and fuel maps are adjusted to compensate for the increase in air and fuel which allows the ECU's algorithms to properly "run" your engine (within reason).

[slowbubblecar]

I think it has to do with being able to be in the right timing maps. The car will idle like stock without having to be so negative on the safc and will be easier to tune. I think you can be running in the wrong timing map if you have big injectors where you are way negative. What do you have your safc for idle? I would personally ditch the 5 know and get the blue faced model one above it.

I have a socketed eprom and just had a chip burned for it to idle my 780s as stock. I would probably need to be around -45 or so on the safc and it is a lot harder to tune like that.

[slowbubblecar]

having a socketed eprom also is helpful because you can have a studder box programed in, it setup to compensate for 2g mas, no fuel cut and many other things. If you look at the dsmchips site, there is a big list of what can be done.

[sleepydsm]

Yeah, I have a MAFT so the injectors are compensated. Then the AFC is used to adjust off of that. I know I'm running super rich, because I shoot flames when I shift at WOT and my exhaust tip is all black. So I have no negatives on the AFC, everything is positive. I figured, since the injectors are compensated, I should start at zero on the afc and then I added fuel as needed.

[tim]

I dont have much technical to add to this but talk to "Steve" on toonerz and you will get all the help you need. He is very helpfull.

[Jakey]

"Steve"
http://simon.chi.il.us/ECU/Index.html

[sleepydsm]

thanks guys.

[sleepydsm]

So do you guys think a 5knob AFC is really holding me back?

[slowbubblecar]

I think is is much easier to tune with the electronic one as you can set high throtle and low throttle settings as opposed to just one setting.