Closed loop corrections

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
aleksanderk
Posts: 68
Joined: Fri Feb 01, 2019 4:36 pm
ECU Model: S80 Pro
Firmware Version: 6500

Re: Closed loop corrections

Post by aleksanderk »

I see. I got the impression that allowing it too much correction would be bad by reading on the forums.
This are my current settings that I will try out the next time I'm out with the car. Any suggestions and tips based on this?
By the way: The manual does not say anything about the Idle mix TPS values. Could that be one of my issues? I believe that this value is the treshold for idling? Should probably set to 0 or 1% as no throttle is 0%?

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Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Closed loop corrections

Post by Rob Stevens »

I wouldn't suggest -30% try -10% first.
You are using the 14x20 target table, raise idle mix to 1000 rpm and the tps% to just above where you car sits at idle.
does your lambda warm up within 5 seconds of start up? one of my innovates takes 35 seconds.
as you are on map im not sure the tps band will do anything? Question for Alex I think. Might still work as % of map
Main sample rate may be a bit fast, try 3.
At idle try the +/- 3% perturb and see how the system responds, use the graph display to view
aleksanderk
Posts: 68
Joined: Fri Feb 01, 2019 4:36 pm
ECU Model: S80 Pro
Firmware Version: 6500

Re: Closed loop corrections

Post by aleksanderk »

Rob Stevens wrote:I wouldn't suggest -30% try -10% first.
You are using the 14x20 target table, raise idle mix to 1000 rpm and the tps% to just above where you car sits at idle.
does your lambda warm up within 5 seconds of start up? one of my innovates takes 35 seconds.
as you are on map im not sure the tps band will do anything? Question for Alex I think. Might still work as % of map
Main sample rate may be a bit fast, try 3.
At idle try the +/- 3% perturb and see how the system responds, use the graph display to view
I noticed that yesterday when testing the car too much correction makes the car jerk some times. Reducing the allowed reduction seems smart :)
Seemed ok when driving, and I noticed that some of my cells actually needed 20% correction :o Took it for a little trip with rpm band at 200, and reduced it to 150 after a couple kilometers.

When cold starting I wait for the heater to warm up before cranking, but it could be increased to 15 seconds.

Changes made:
Main sample rate reduced to 3hz.
PID set to default 200/0/0 again.
Raised idle mix to 1000 (Not sure what this does though).
Reduced Idle mix TPS to 1% since idle is at 0% TPS.
Increased delay from start to 15sec.

I also reduced overrun rpm to 1500 from 2300 because the car is jerking when i pass the treshold.
Will test with perturbfuelling.

Thank you for all your input and help! I really appreciate it :D
stevieturbo
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Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Closed loop corrections

Post by stevieturbo »

IMO, stop getting obsessed with fuel correction maps.

You'll forever chase your tail. Get it so it drives good everywhere, manually tuned, open loop, and then allow some closed loop corrections to try and clean things up as you drive if need be.
Small -ve corrections, because pulling fuel if it is not needed, will have a negative effect on driveability. And moderate +ve corrections. Whether for safety, or just because.

But following correction maps, you'll forever be going around in circles.
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Closed loop corrections

Post by Rob Stevens »

I'm inclined to agree with Stevie, run it open loop for a bit to see where the map is not good, I use the close loop to target >1.05 when cruising to save fuel, one day the correction map may say +8% the next day -5% and I've made no changes. but you can see on the real time chart what is happening. I feel there is a bit of fudge going on as the conditions are never the same, I am on tps/rpm only however.
However for years I've been trimming fuel out of my map and it feels sharper.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Closed loop corrections

Post by stevieturbo »

It's not that there's a fudge...

air temp, humidity, load, perceived charge temp and just a lot of variables will impact things. OEM's spend a clean fortune and thousands of hours getting everything right, and they use more load measurements than we would, MAF being particularly good.

A more basic system is never going to be 100%, 100% of the time. But it doesnt need to be. Just don't have it going lean in places, as that is the main thing that you will feel as something bad when driving.
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