economy tuning
This is the thing with ethanol flex fuel cars, the egr dilution factor can tolerate very lean conditions allowing the fuel economy to outweigh gasoline on a gal to gal basis. Esp with DI ethanol/port gasoline turbo engine, they were also able to push the HP this way much further than any alky kit would
I would think you could, if somehow you were able to look at an average IPW over say one tank of gas. That would be a ton of logging though.
If your fuel pressure system remains unmodified during the course of two tank fulls of gas, one tank for non-economy and one for economy, your IPW's should decrease on the average because they aren't firing as long as with a 15.7 afr than a 14.7 afr.
I bet it could be quantified by IPW, but that a ton of logging, everytime you drive the car, for as long as you drive it, for two entire gas tank fulls.
If your fuel pressure system remains unmodified during the course of two tank fulls of gas, one tank for non-economy and one for economy, your IPW's should decrease on the average because they aren't firing as long as with a 15.7 afr than a 14.7 afr.
I bet it could be quantified by IPW, but that a ton of logging, everytime you drive the car, for as long as you drive it, for two entire gas tank fulls.
T-So I need a log that is at least 2 seperate tanks full and see what the average IPW seems to be cruising? I could have someone ride shotgun on a 300mi roadtrip and watch the IPW flat cruising at a known constant TPS and Vacuum and then see what the IPW is. Otherwise I'd end up with a 6gb log I think. IF it needs to be done though it needs to be done.
C6- thanks for clearing that up
I knew there was more to it than I was seeing or reasoning on, I just hadnt figured it out.
Running around 15.8:1 I was able to get 330 miles on one tank. This was mostly 5th and 6th gear cruising and almost no boost.
I added the lean cruise settings mainly because I drive over several foothills on the way to and from work every day and was getting like 220 miles per tank. Now I generally get 240-260. This is obviously due to the fact that the engine is loaded significantly more traveling over the hills than on level terrain.
I say that the open loop cruise works.
I added the lean cruise settings mainly because I drive over several foothills on the way to and from work every day and was getting like 220 miles per tank. Now I generally get 240-260. This is obviously due to the fact that the engine is loaded significantly more traveling over the hills than on level terrain.
I say that the open loop cruise works.
This is the nice thing about the zeitronix wideband. If you hook up the simulated narrowband O2 sensor wire to the front O2 sensor input on the ECU (your replacing the front O2 signal completely), you can set the stoich switching point from 14.7 up or down and it works like a charm. True closed loop adjustments and no need to fidget with fuel cell #'s. 15.5:1 worked well for me, I usually hit 220 miles per tank as well at 14.7:1, I hit around 260-270 at 15.5:1.
This is the nice thing about the zeitronix wideband. If you hook up the simulated narrowband O2 sensor wire to the front O2 sensor input on the ECU (your replacing the front O2 signal completely), you can set the stoich switching point from 14.7 up or down and it works like a charm. True closed loop adjustments and no need to fidget with fuel cell #'s. 15.5:1 worked well for me, I usually hit 220 miles per tank as well at 14.7:1, I hit around 260-270 at 15.5:1.
I need to get a wideband display and a boost gauge or something.
I get 220 to till the light turn on but I can drive to aprox 250 -260 with the ligh on at 15.7:1 - 16.1:1 wiht the above alteration (LC-1 NB simulator)
how much would i b able to increase afr's if i stay in closed loop (keeping egr working), like Jack_of_Trades did??
would doing this require adjusting fuel trims or they'll be okay???
rgds+
would doing this require adjusting fuel trims or they'll be okay???
rgds+
Last edited by EE; Feb 13, 2008 at 12:43 PM.
Higher EGT's for longer durations which I suppose could take a toll on spark plug ceramic parts perhaps? As long as knock isn't an issue, EGT's are the main thing I could think of.
From what I've read online, 14.7 is the chosen a/f ratio for closed loop operations because of emmissions reasons. It keeps the catalytic converter hot enough to do its job.