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Cuntousaurus
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Discussion Starter #1 (Edited)
Disclaimer - Not the place to argue about tuning/mapping what is best flash/standalone. If this gets dragged off topic would a mod kindly slap the individual hard please

Right, I found this document on the web which has me quite interested in how the EMS2000 functions:

http://www.bmw-planet.com/lib/mini/ENGINE MANAGEMENT OVERVIEW.pdf

A few bits in particular caught my attention so would like to start a discussion on how this affects the car day to day, and more so when you start bolting parts to the car and mapping it. The first area of business is this chap called the "Torque Manager"... (Page 72)

Internal combustion engines generate torque by being supplied with a correctly mixed quantity of fuel and air, which is ignited at a precisely calculated time. By varying the quantity of air/fuel and the timing of the spark, the torque output can be altered. However, altering the quantity of fuel relative to the airflow can adversely affect catalyst life, combustion chamber and piston temperatures.

Therefore, when the EMS2000 varies the torque in response to the demands of the previously mentioned
systems, it achieves this by altering only the ignition timing and/or throttle position. Certain characteristics are
involved in these two methods of torque alteration:


  • Ignition Timing - Ignition Timing can be altered rapidly and gives an instant torque change however, because under normal circumstances the EMS2000 always ensures that the engine runs at peak efficiency.

    [*]Throttle Position - By changing the Throttle Position (airflow) the engine torque can be increased or deceased. If airflow is increased or decreased the EMS2000 automatically maintains the correct fuel mixture by balancing the fuel input. Unlike the rapid torque change achieved by altering the ignition, changes in throttle position take longer to achieve torque variation. Each system can demand either a slow or fast torque variation.
Okay, if I'm reading this correctly, in closed loop operations the ecu will adjust the Ignition timing and throttle position to acheive what it refers to later in that page as the "required torque": "Torque coordination: this function determines the ignition and throttle settings needed to produce the
required torque."


What happens if you add BVH, a pulley, cam etc and your engine produces more torque? Is this "required torque" a hard coded value at a given throttle input/rpm value that must be altered in order to ensure you car won't alter the ignition and thottle position back to maintain stock torque, and if you do change it what if your car doesn't make that value? Can it be a maximum or does it need to be accurate?

Is this something that would affect the map when running in open loop as well?

Hopefully this can be used to help us understand more in regards to how our cars respond to engine changes and why a map is an essential part, theres lots of talk about changing they pulley, intake, injectors, exhaust, manifold etc and no change to the ecu coding so would be great to get a discussion going.

Please keep this on topic, this is not the place to sell your products, big up your ego or put others down on their chosen route. It's a while since we have had something like this on MT since it "changed" so hopefully it will work better now.
 

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I wonder if by knowing this info you can get an idea of how much fuel is needed and if your injectors are up to the task (pretty sure mine are flat out). What I mean by this is I guess it's going to give us a good idea of what else needs changing as the car 'adapts' to it's upgrades.
 

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Throttle position is only for situations such as traction control and in the stock Cooper S map (not JCW) it restricts the throttle opening to ~70% (IIRC) until ~4,500RPM. Regardless what that document say's the constantly changing fuel demand when in closed loop (idle and cruise fuelling) will still more than likely be handled by altering the fuel map
 

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Good thread, as the title seems to imply I can ask other questions in here as well - can someone run by me what a standalone ECU is and the purpose of having one?
 

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I would suggest keep standalones to a seperate thread, that will confuse matters.

It was more the ignition timing adjustments that have me concerned as you can see short term fuel adjustments via obd but the ignition one is hard to check.
AFAIK the ECU has no capability to adjust the ignition timing or TP on a long term basis
 

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How do the JCW and GP maps differ? And how different are they from stock? Is it really a case of the stock map being effectively a de-tune so as create an artificially large gap between stock and the JCW?
It would be interesting to know if the JCW/GP maps are better at handling upgrades than stock.
 

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This is a very interesting read, will take some time to read through
but will probably be able to get rid of some myths and speculation over the R53 ecu
 

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Cuntousaurus
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Discussion Starter #12
AFAIK the ECU has no capability to adjust the ignition timing or TP on a long term basis
Yeah, but if it does adjust it on the fly as described in the tech document it obviously would mean your fuel consumption might be affected more than it needs to be (ie. Retarding ignition to the point of killing mpg so it can meet it's torque requirements). I have noticed immediate improvements in driveability and throttle feel after a flash/map change/adaptation clear when we were working on the map (checking LTFT and making fuel map adjustments accordingly). So would be good to get a definite answer on this.

Yeah,, what is he reason behind this? (if what your saying is remotely correct) ::popcorn::
Is it correct? Sounds pretty annoying really, I think mine was based of a JCW map but not sure. Any ideas on the questions regarding Torque management?
 

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Yeah,, what is he reason behind this? (if what your saying is remotely correct) ::popcorn::
To make sure grannies/hairdresser's/estate agents/gay's have a nice lazy throttle at the rev's they'll spend all their time in I guess, you're undoubtably the expert and you've presumably seen the rock stock (not remapped in any way) map so you'll be able to confirm whether it's true or not :)
 

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I think some people are slightly missing what is going on here
on the next section "Torque Control" it lays out exactly when torque control is varied, the only internal variations listed are Idle Control, Catalyst 'light up' and overheat protection and Limp home control.
Basicly that means it can vary the throttle on idle slightly, for anti stall etc and can limit you if you're in limp mode, before the cat is up to temp, and when the cat is overheating, no idea when the cat protection kicks in (possibly triggered by IAT temps), but you would know if you are in limp mode. So other variations in the torque can only come from the other systems listed (DSC/ASC automatic transmission and cruise control) and the driver demand (throttle pedal) .

According to this on a manual transmission with DSC turned off, with no limp mode, no cat protection active and no cruise control on, the throttle pedal is the only thing that can control the torque above idle
If the throttle on the R53 was being even slightly limited by the ecu up to a certain rpm, we would see it on the dyno, and feel it on the road (vtech kicked in yo)
 

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Cuntousaurus
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Discussion Starter #15
I think some people are slightly missing what is going on here
on the next section "Torque Control" it lays out exactly when torque control is varied, the only internal variations listed are Idle Control, Catalyst 'light up' and overheat protection and Limp home control.
Basicly that means it can vary the throttle on idle slightly, for anti stall etc and can limit you if you're in limp mode, before the cat is up to temp, and when the cat is overheating, no idea when the cat protection kicks in (possibly triggered by IAT temps), but you would know if you are in limp mode. So other variations in the torque can only come from the other systems listed (DSC/ASC automatic transmission and cruise control) and the driver demand (throttle pedal) .

According to this on a manual transmission with DSC turned off, with no limp mode, no cat protection active and no cruise control on, the throttle pedal is the only thing that can control the torque above idle
If the throttle on the R53 was being even slightly limited by the ecu up to a certain rpm, we would see it on the dyno, and feel it on the road (vtech kicked in yo)
Think you need to read it again....

"The Engine Management System (EMS2000) has the ability to vary the torque output of the engine in response to demands from several systems. These demands can be divided into three categories"

Those 3 being Engine running demands, Powertrain and chassis demands and the one I'm refering to, Driver demand.

Driver demand

The EMS2000 is programmed to decide which of the torque variation demands is the most important and will then act upon that demand. This task is performed by the EMS2000 'Torque Manager' which performs two main functions:

  • Torque selection: this function decides which of the torque demands shall be acted upon.
  • Torque coordination: this function determines the ignition and throttle settings needed to produce the required torque.
 

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Cuntousaurus
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Discussion Starter #17
driver demand is the throttle pedal
I talks about all 3 in a separate context, my understanding from that document is the ecu will alter the ignition timing and throttle position to meet the required torque, more so the ignition. The question still is there as to is this a hard coded value and what happens if you increase the power and more importantly torque and it then exceeds this value?
 

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i think you are over thinking it, there are no absolute torque values involved, there is no way for the ecu to even measure them, if there was, we wouldn't need dynos.
torque control requests can be for an increase, a decrease or a set amount (fraction or % of max)
the ecu must evaluate all requests and decide which is the most important, the driver input must be the lowest priority of all otherwise the constant signal from the pedal would block any other requests
 

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i'm not sure there is any at all slow about the stock ECU, it should be perfect for the job, the reason for a stand alone is total control and programmable, from what i have read ZzzzzzZ has completely rewritten the firmware on the stock ECU with his own, making it to him at least as good as a stand alone
 

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Cuntousaurus
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Discussion Starter #20
i'm not sure there is any at all slow about the stock ECU, it should be perfect for the job, the reason for a stand alone is total control and programmable, from what i have read ZzzzzzZ has completely rewritten the firmware on the stock ECU with his own, making it to him at least as good as a stand alone
If this is the case, maybe he could shed some light on the questions raised here? :)
 
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