Simulated narrowband for closed loop.
11-14-05, 11:59 PM
#1
Simulated narrowband for closed loop.
I got it hooked up and now i'm doing something like 17s to mid 18s AFR at throttle inputs of around 35-49% (S-AFC, no load based tune )
Does anyone with an S-AFC use closed loop? I'm thinking I may have to shift my maps out of the 'loop' range so that I don't get such lean AFRs, though EGTs stayed stable and the car didn't fall on its face.
Anyone have any input?
Started in this thread.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/narrowband-output-482069/
Does anyone with an S-AFC use closed loop? I'm thinking I may have to shift my maps out of the 'loop' range so that I don't get such lean AFRs, though EGTs stayed stable and the car didn't fall on its face.
Anyone have any input?
Started in this thread.
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/narrowband-output-482069/
11-15-05, 12:30 AM
#2
I don't understand what you're asking.
The stock ECU, with O2 sensor input, will TOTALLY IGNORE the AFM data (coming through the SAFC) and run purely on the O2 sensor output. The only way to force SAFC corrections constantly is to disconnect the O2 sensor. Amusingly enough, I think I see better economy with the O2 sensor disconnected and the SAFC tuned slightly lean, but that's a side note.
What all do you have feeding inputs into what? It sounds like you have a wideband & controller, feeding a fake O2 sensor input into the ECU.
-=Russ=-
The stock ECU, with O2 sensor input, will TOTALLY IGNORE the AFM data (coming through the SAFC) and run purely on the O2 sensor output. The only way to force SAFC corrections constantly is to disconnect the O2 sensor. Amusingly enough, I think I see better economy with the O2 sensor disconnected and the SAFC tuned slightly lean, but that's a side note.
What all do you have feeding inputs into what? It sounds like you have a wideband & controller, feeding a fake O2 sensor input into the ECU.
-=Russ=-
11-15-05, 12:56 AM
#3
I have a Tech Edge 2B0 Controller using a Bosh LSU sensor. The 2B0 supports what they call NBsim which is a 0-1v output using an interpolation table derived from the narrowband signal. That way its as if the car does have a narrowband sensor for the ECU to do closed loop.
I already get 20-21 MPG with mixed highway/city miles. I just want to squeeze some extra out of her. Maybe get it up to 24-25. I normally cruise at 13.9-14.3afr without closed loop only on S-AFC settings.
If what you say about closed loop is true then my ECU is freaking insane because i'm not seeing 14.7 i'm seeing 17s+ I believe that my low throttle map on the s-afc is affecting the closed loop but I may be wrong.
Santiago
I already get 20-21 MPG with mixed highway/city miles. I just want to squeeze some extra out of her. Maybe get it up to 24-25. I normally cruise at 13.9-14.3afr without closed loop only on S-AFC settings.
If what you say about closed loop is true then my ECU is freaking insane because i'm not seeing 14.7 i'm seeing 17s+ I believe that my low throttle map on the s-afc is affecting the closed loop but I may be wrong.
Santiago
