Are the O2 sensors used at all in open loop? What about Speed Density, do they use the o2s at all too? TIA

 

O2 sensors are ignored during closed loop. The car will not go into closed loop until the O2 sensors are heated to about 600-700 F, so they can properly read the oxygen content. The car will go off the open loop a/f ratio tables. Speed density does use O2 sensors, however, I am not sure on how they work specifically. I would assume they work very similar to how MAF cars work.

 

thanks for the info. i just ordered a wideband o2 sensor and i'm planning on installing it in the stock location and just running an open loop program so i won't have to run the stock o2s.

 

Should read "O2 sensors are ignored during open loop"

 

Yes, Dan K is right, that is SUPPOSE to read OPEN LOOP! I don't know what I was thinking, work must have been getting to my brain when I posted that. Everything else in the post was correct though. 3rd shift can be very mind numbing somtimes!

 

yea, i kinda figured that it should read open loop instead. i had to re-read it a couple times though.

hmm...now i'm wondering if open loop and speed density can be used at the same time. so i could get rid of the stock o2's and the maf. and maybe switch over to one of the old style sbc intakes. hmmm...

 

I don't see why you can't go open loop and speed density.

 

I am currently testing my car in Speed Density mode and Open Loop Mode. The car runs ok but you MUST have a wideband O2 setup to get the VE tables right. From my experience I think running in Open loop MAF mode works best. It allows for weather compensation and more accurate fuel delivery. Speed Density is good but much time needs to be invested to get them right. I am going to get a DFI 7 unit and wideband monitor for my car, this is the only reason I have been playing with my car in open loop and speed density mode. Personally I am putting my car back into open loop MAF mode, it just runs the best there. my cars cam is so big at an idle the O2s are going nuts in closed loop mode since so much O2 is going into the exhaust due to the cams extreme overlap.


OPEN LOOP AND SPEED DENSITY MODE = not so great