Apexi Power FC - closed loop?
09 December 2004, 01:04 PM
#1
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Apexi Power FC - closed loop?
Does anyone know if the Apexi Power FC has a closed loop narrow band lambda control feature or is it purely open loop?
Cheers,
dr_jones
Cheers,
dr_jones
09 December 2004, 05:07 PM
#3
Originally Posted by stevebt
it must be able to do closed loop as it was set on closed loop on mine for a month or so till i got my new O2 sensor
10 December 2004, 09:22 AM
#6
Originally Posted by Andy.F
As mentioned above, yes it has 
It's switchable and selectable in which zones you use it.
Andy
It's switchable and selectable in which zones you use it.
Andy
How exactly can you select the zones in which to use it? Is that what the 1.047 figure is about? Anything under that number in the fuel map is available to use closed loop?
Might explain a few things with it turned on with my own car if that's the case. However I thought it was a target fuelling number. As I lowered it the closed loop lambda appeared to give higher AFR.
Paul
10 December 2004, 09:54 AM
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Originally Posted by Pavlo
Andy,
How exactly can you select the zones in which to use it? Is that what the 1.047 figure is about? Anything under that number in the fuel map is available to use closed loop?
Might explain a few things with it turned on with my own car if that's the case. However I thought it was a target fuelling number. As I lowered it the closed loop lambda appeared to give higher AFR.
Paul
How exactly can you select the zones in which to use it? Is that what the 1.047 figure is about? Anything under that number in the fuel map is available to use closed loop?
Might explain a few things with it turned on with my own car if that's the case. However I thought it was a target fuelling number. As I lowered it the closed loop lambda appeared to give higher AFR.
Paul
When you lowered it you probably went open loop in more zones ?
With a bit of creative thinking, offsetting a sim NB signal, it would be possible to run closed loop at WOT with an appropriate AFR target
Andy
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24 December 2004, 01:57 PM
#8
Originally Posted by Andy.F
Thats correct, it's not a target AFR. Closed loop fueling is turned on in any cell under the 1.047 (this number may be set wherever you want) The narrowband voltage needs to 'trip' the stoich point initially to enable it though, ie if you have a sleepy sensor, it will wait on it warming up before controlling on closed loop.
When you lowered it you probably went open loop in more zones ?
With a bit of creative thinking, offsetting a sim NB signal, it would be possible to run closed loop at WOT with an appropriate AFR target
Andy
When you lowered it you probably went open loop in more zones ?
With a bit of creative thinking, offsetting a sim NB signal, it would be possible to run closed loop at WOT with an appropriate AFR target
Andy
I know what you mean about the trippig, I usually get it to trip as I blip the throttle and it goes lean on overrun.
Paul
24 December 2004, 02:07 PM
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ah, interesting
in which case, how can you control the target AFR for closed loop fueling ? or cant you?
Steve
in which case, how can you control the target AFR for closed loop fueling ? or cant you?
Steve
Last edited by ScoobyDuck; 24 December 2004 at 02:11 PM.
24 December 2004, 02:29 PM
#10
I don't think you can.
As any says, what I observed were fewer cells being in closed loop mode when i changed the threshold, and in open loop these cells were lean.
Paul
As any says, what I observed were fewer cells being in closed loop mode when i changed the threshold, and in open loop these cells were lean.
Paul
24 December 2004, 05:18 PM
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Originally Posted by Pavlo
I don't think you can.
Paul
Paul
You need a narrowband sim signal switching at an offset value from stoich.
You run this as per normal at cruise then vary the target(signal) by either tps or load value, it means putting a lot of faith in your wideband but if you set alarm points on this at WOT it minimises the risk.
Andy
24 December 2004, 06:15 PM
#12
I meant not within the (powerfc) box. However I am not sure how the speed of response is. Looking at AFR as the engine is under closed loop control shows there to be a very wild swing in AFR. With a customised AFR response you may be able to damp that somewhat, but I don't want to be the one trying it on boost the first time if the AFR swings from 13.5 to 10:1 repeatedly!
Paul
Paul
24 December 2004, 06:28 PM
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It only swings a little, the narrowband signal looks wild but that is because the sensor gain is so high at switch point. If you monitor the injector duty you will see a signal swing of less than 0.2%duty (assuming you mapped closely in the first place !) Typically at higher rpm there is a quicker reaction cycle time and it maintains target very well considering there is enrichment fuel being thrown in at every +ve blip of the throttle.
Andy
Andy
24 December 2004, 06:59 PM
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which is a shame, as ecu's like the LINK have lambda targets for different zones.
would have been nice to increase the AFR a bit for main cruse areas to offset the WOT bits 
in comparison the increase would be 0.001sec on WOT
would have been nice to increase the AFR a bit for main cruse areas to offset the WOT bits
in comparison the increase would be 0.001sec on WOT
24 December 2004, 07:13 PM
#16
My closed loop response can very, sometimes it's very stable, others it fluctuates wildly depsite hovering at a steady 0.5-0.58 volts on open loop.
Although I have jst thought that may be down to the 850s less than "fine" nature at low duty cycles. I will check the INJ and check that against AFR on some logs.
Paul
Although I have jst thought that may be down to the 850s less than "fine" nature at low duty cycles. I will check the INJ and check that against AFR on some logs.
Paul
Last edited by Pavlo; 24 December 2004 at 07:15 PM.
24 December 2004, 07:32 PM
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Originally Posted by ScoobyDuck
which is a shame, as ecu's like the LINK have lambda targets for different zones.
would have been nice to increase the AFR a bit for main cruse areas to offset the WOT bits
in comparison the increase would be 0.001sec on WOT
would have been nice to increase the AFR a bit for main cruse areas to offset the WOT bits
in comparison the increase would be 0.001sec on WOT
Andy
24 December 2004, 09:52 PM
#18
Yes, the early links you could only switch on and off tho. The later ones you could have on, off or half (i.e vacumm plus a bit of boost). So on my early link i had 6 AFR (well voltage) targets (one for each row)..... but it was slow to respond and i wouldn't trust it to do the fueling on a lawnmover!!!!
Tony.
Tony.
24 December 2004, 09:52 PM
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YUP !
Lambda @ Idle
Lambda @ Cruse
Lambda @ Row 4
Lambda @ Row 5
Lambda @ Row 6
it also has HALF or FULL mode closed loop !!
what it lacks in cells, it makes up for (edit - ok, well, maybe not coz what Tony said )
Steve
Lambda @ Idle
Lambda @ Cruse
Lambda @ Row 4
Lambda @ Row 5
Lambda @ Row 6
it also has HALF or FULL mode closed loop !!
what it lacks in cells, it makes up for
(edit - ok, well, maybe not coz what Tony said )Steve
24 December 2004, 09:55 PM
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i've had to type on a full stomach !!! (just got back from a massive meal)
was your early LINK closed loop rubbish then?
I was contenplating getting another boss for the wideband to go in and putting back the OEM, but now you can change the scaling on the TE wideband's NBSim output, i'm gona try to find the correct scaling for the OEM and plug that in and try it...
Steve
was your early LINK closed loop rubbish then?
I was contenplating getting another boss for the wideband to go in and putting back the OEM, but now you can change the scaling on the TE wideband's NBSim output, i'm gona try to find the correct scaling for the OEM and plug that in and try it...
Steve
24 December 2004, 10:02 PM
#22
Rubbish isn't the word. Andrew has had some joy using half mode on his later Link, personally it was so sloooooow to react and seemed to swing about so windly i only tried it in rows 1-4. Didn't fancy it trying to control at 1.2 bar.
I can't believe i actually paid £700 for it... compared to the Apexi it seems so 'old tech'.
How far off is the NBSim from OEM, can't be that far can it as i'm getting great results from it..... wouldn't mind knowing how you go tho.
Tony.
I can't believe i actually paid £700 for it... compared to the Apexi it seems so 'old tech'.
How far off is the NBSim from OEM, can't be that far can it as i'm getting great results from it..... wouldn't mind knowing how you go tho.
Tony.
24 December 2004, 10:08 PM
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well, i think the early LINKs had a slower chip, but even the newer ones arent that fast. And i know what you mean by low-tech, but they do the job.
I'm not sure how far out it is, as most ppl have the OEM sensor in. You & Andrew use the NBsim without issue, but mine sends it all over the place. so much so that it makes the purge valve tick all the time on idle. Cant remember what the voltage swings were on the Commander, but they were stupid, even at cruise.
Andrew did point out this fact to me, but we've been waiting for the WBCONFIG software to be able to change it. Not manged to find out how yet though!
NBSim output
Steve
I'm not sure how far out it is, as most ppl have the OEM sensor in. You & Andrew use the NBsim without issue, but mine sends it all over the place. so much so that it makes the purge valve tick all the time on idle. Cant remember what the voltage swings were on the Commander, but they were stupid, even at cruise.
Andrew did point out this fact to me, but we've been waiting for the WBCONFIG software to be able to change it. Not manged to find out how yet though!
NBSim output
Steve
Last edited by ScoobyDuck; 24 December 2004 at 10:12 PM.
24 December 2004, 11:46 PM
#26
Oh yes.... So Andy do not fancy running an early link with 3 bar map sensor option at 1.8 bar on closed loop fueling hoping it gets somewhere close to its target of 0.87 volts on row 6 from the oem narrow band.
Piece of **** this mapping... let the ecu do it all for you. Just put in the right voltage/target and jobs done .
Tony.
Piece of **** this mapping... let the ecu do it all for you. Just put in the right voltage/target and jobs done
.Tony.
24 December 2004, 11:51 PM
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I presume it 'purges' when it thinks things are too rich in a certain state. This state was being met on idle. blipping / raising the throttle stopped it, but then it restarted when idle resimed. it did however pass the MOT like that 
