Quasi-Closed loop?
05-23-2024, 05:53 PM
#1
Supreme Member
Thread Starter
Quasi-Closed loop?
I found these two scalars in the S_AUJP xdf for $8D...
Loop Closed Param, SLOW o2 Coolant Temp Factor 0x4A0 Factory setting => 60.2%. No description on what it does.
AIR FUEL Param, Coolant lag filter coefficient 0x3E7 Factory setting => 6.27% No description on what it does
I was curious what they do, so I started playing around with them, iterating my way to an actual result. I had them at zero, 50% and everywhere in between.
In the end, I wound up with both of them at 100%, and I have to say the car runs more consistently (in terms of seat-of-the-pants power... over varying air and coolant temperatures). Have no idea why. It's not night vs day difference, but I can definitely feel it. It was pretty consistent before, but as picky as I am, I can feel the improvement and I'm liking it... lol.
The only thing I notice in terms of running data is that the BLMs are now essentially locked at 128, with only the integrator varying. Almost like a "quasi-closed-loop".
I had the BLMs pretty narrowly dialed before in such that I was between 124 and 132 at all times. So I'm not too concerned about having them locked at 128, and the AFR's look really good on the WB. So I'm going to leave it like this I think.
Out of curiosity, if anyone knows what exactly it was I did I'd like to know.... lol.
Loop Closed Param, SLOW o2 Coolant Temp Factor 0x4A0 Factory setting => 60.2%. No description on what it does.
AIR FUEL Param, Coolant lag filter coefficient 0x3E7 Factory setting => 6.27% No description on what it does
I was curious what they do, so I started playing around with them, iterating my way to an actual result. I had them at zero, 50% and everywhere in between.
In the end, I wound up with both of them at 100%, and I have to say the car runs more consistently (in terms of seat-of-the-pants power... over varying air and coolant temperatures). Have no idea why. It's not night vs day difference, but I can definitely feel it. It was pretty consistent before, but as picky as I am, I can feel the improvement and I'm liking it... lol.
The only thing I notice in terms of running data is that the BLMs are now essentially locked at 128, with only the integrator varying. Almost like a "quasi-closed-loop".
I had the BLMs pretty narrowly dialed before in such that I was between 124 and 132 at all times. So I'm not too concerned about having them locked at 128, and the AFR's look really good on the WB. So I'm going to leave it like this I think.
Out of curiosity, if anyone knows what exactly it was I did I'd like to know.... lol.
06-08-2024, 11:39 AM
#2
Supreme Member
Thread Starter
Re: Quasi-Closed loop?
Another one...
AIR FUEL Param, TPS Initialization Voltage Filter Coefficient 0x3E6
Set to 100%
I'm not sure what it is with these filter coefficients and why 100% seems to be such an ideal value for a performance oriented tune. I don't even know how to describe it, but there's this seat-of-the-pants feel to it now at part to moderate throttle that feels like the ECM has been transformed into more of a performance ECM rather than one that was made for a generic production car.
It's not like the car is running richer or anything like that (I'm not seeing any noticeable difference in the AFR's ether during throttle transitions or at steady state). But something is different in the way the fueling is being applied with all these filter coefficients at 100%.
What I was chasing after in this thread.... it actually runs better than that now...
https://www.thirdgen.org/forums/diy-...rt-7730-a.html
AIR FUEL Param, TPS Initialization Voltage Filter Coefficient 0x3E6
Set to 100%
I'm not sure what it is with these filter coefficients and why 100% seems to be such an ideal value for a performance oriented tune. I don't even know how to describe it, but there's this seat-of-the-pants feel to it now at part to moderate throttle that feels like the ECM has been transformed into more of a performance ECM rather than one that was made for a generic production car.
It's not like the car is running richer or anything like that (I'm not seeing any noticeable difference in the AFR's ether during throttle transitions or at steady state). But something is different in the way the fueling is being applied with all these filter coefficients at 100%.
What I was chasing after in this thread.... it actually runs better than that now...
https://www.thirdgen.org/forums/diy-...rt-7730-a.html
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