EFI Presentation

[BLKMGK]

Though thtis link sent to me by the FAST people migh tbe of interest

http://www.fuelairspark.com/common/information/presentations/fast/001/Default_fil es/frame.htm

It's a presentation that one of their engineers gave at a conferenece concenring EFI technology. Not sure there's anything new in it for those of us who understand eFI but for those just learning perhaps it will have some value. I'm still reading through it too so perhaps there's some neato' bits in there I've not yet seen

 

Okay - slides 27, 28 and 36 ought to be of particular interest. 27 and 28 show the response curves of both normal O2 and WB O2. You can sort of see why the voltage meters everyone uses on normal O2s don't work real well. The voltage curve given for the WB is probably AFTER a little black box that smooths it's response curve out, my understanding is that that little bit of electronics adds to the cost noticably. The sensor itself ain't cheap either.

 

Slide 36 will make the most sense if you've got EFI experience and have looked at the FAST software. The lower screen shows the datalog of a run. As you scroll across the bottom map you would look at the upper map, which is that motors VE table. At each point on the lower map the VE cell that's being used at the time the datalog was created is highlighted AND tracked (it leaves a little tail as it moves in the map). So, if you see a dip in the A/F ratio logged by the WB sensor you can look at the VE map and easily see which cell needs to be modified. There are functions for smoothing the surrounding cells too if I recall. You can do this same tracking with ignition and other tables too I think. DFI GEN7 will highlight cells but it won't "track" with a tail. Frankly, FAST did it better from what I can see.

 

Dunno' yet about the AEM software - the Beta stuff out there is apparently GEMS which the rally guys use and VERY flexible (you can suppposedly program LOT'S of triggers etc.) but pretty crude for someone who doesn't know much about EFI and exposes some seriously low level functions that no other unit I've seen exposes (sensor specs for instance). Talking to people who DID approach the AEM table at SEMA I've been told that it will actually modify the VE fueling maps to hit your programmed target A/F ratios Dunno' yet if th eothers can do this or if the AEM unit does it on the fly or not. I'd think postprocessing would be the best way to go for that.

 

Okay, enough rambling. Hope someone gets something out of it at least

[Guest Anonymous]

You are perhaps the very first person who ever in my life showed me slides on the internet in a forum... Yawn, must be getting late... "But Wait, Look, this is me poking this bear in the butt with this stick, oh yeah, this is me in the hospital" hahahaha... Sorry couldn't resist. That is a cool presentation in all honesty, just busting your hump....

 

Regards,

 

Lone