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Old 06-30-2011, 03:46 PM   #91
The Griz
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Originally Posted by Gangplank View Post
Maybe you convinced him we were right before we were right.
We can only hope! Because what I said back then and what you are saying now are the facts!
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Old 06-30-2011, 07:10 PM   #92
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thanks for someone sending me a link to this....

This is a graph from a dyno of a F800ST. Ours will be slightly different but it shows the AFR made by the motor as measured at the tailpipe while the bike is on the dyno.



See that dotted line at 13. That is what the recommended AF ratio is for any regularly aspirated motor. The F800 motor runs lean. Very lean in fact.
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Old 06-30-2011, 07:40 PM   #93
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Check out the following snip from this post as part of this thread.

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Originally Posted by jenslh View Post
Open loop (BoosterPlug is active) is everytime you shift the throttle position or the RPM to a different cell in the fuel map: Accleration, engine braking, and low speed running are open loop conditions. (In idle and low speed conditions, the cells in the fuel map is very closely spaced, so even if you think you are not changing throttle or RPM's, you will still be shifting cells, because the slightest variation in RPM will take you to the next cell in the map - and go open loop)

Closed Loop (BoosterPlug is inactive) is when you maintain a constant speed on the open roads - Touring. Here you will stay in the same cell in the fuel map for long periods and the O2 sensor will have the time to regulate the mixture back to the factory level. This is what gives you the better mileage.
He also covers that in more detail at the BoosterPlug website under Basic Resistor Tuning.

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Old 06-30-2011, 09:41 PM   #94
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Check out this information on the ECU from Poolside from his thread on a series of products he has been working on.

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Originally Posted by Poolside View Post
Here's a revised table, along with a Glossary of Terms.

I'm hoping to make the subject of fuel injection a little more understandable, or at least approachable. The fundamental operation of EFI, if not the electronics and software themselves, is one of those things that is easy to grasp.

A lot of people who ride are interested in knowing what the ECU is doing, good and bad, to affect the pleasure of riding. If you're one of those people, I hope you find this useful.

Start at the top of the blue column and work your way down. The blue column lists a common sequence of rider inputs. Traveling at a constant speed, rolling on the gas, speed increase, rolling off the gas, speed decrease.

The green boxes are the ECU subroutines, or algorithms if you like, that 'execute' based on what the rider is doing with the throttle. The subroutines are a set of instructions and procedures to carry out a particular task.




Steady State
Just like it sounds. Throttle is steady and the motor is turning at a constant RPM. Steady State includes a constant throttle and speed on uphill or downhill grade.

Tip-in
Refers to an opening throttle movement. An increase in throttle angle. Tip-in isn't the amount of throttle movement, it's the movement itself. Specifically refers to the duration of time when the throttle angle is actually increasing.

Tip-out
Refers to a closing throttle movement. A reduction in throttle angle. Tip-out isn't the amount of throttle movement, it's the movement itself. Specifically refers to the duration of time when the throttle angle is actually decreasing.

Overrun Fuel Cutoff (or OFC)
Starting from any steady state throttle position, if the throttle is tipped out 15% or more the ECU cuts off all the fuel flow. If the rider closes the throttle completely and allows the bike to slow, fuel cutoff continues. Fuel delivery resumes below 1700 RPM, and is felt as a distinct lurch.

Leading Throttle
Say you're traveling at 35 mph and you tip-in the throttle to 75% and hold it there. The bike is increasing speed but hasn't yet reached its final velocity for the new throttle setting. You can think about that condition in terms of the motor trying to 'catch up' to the throttle. The throttle is ahead of the motor, and is leading it to a new RPM.

Trailing Throttle
Opposite polarity to Leading Throttle. You've backed out of the throttle some and bike is slowing but hasn't yet reached its final velocity for the new reduced throttle setting. The throttle is trailing the motor.

Closed Loop
Closed control loop operation is probably the most complex routine in EFI systems. But to explain it simply, Closed Loop is when the ECU is using O2 Sensor feedback to adjust its fuel calculations. When the ECU is running in Closed Loop, some sensor outputs are ignored and are left out of the fuel delivery calculation.

Open Loop
During Open Loop operation the ECU does not use O2 Sensor feedback to adjust its fuel calculations. And just as with Closed Loop, when the ECU is running in Open Loop, some sensor outputs are ignored and are left out of the fuel delivery calculation.

Transient Enrichment (aka: Accelerator Pump)
Without Transient Enrichment, the motor would stall when you open the throttle. With the right amount of enrichment, the throttle response is crisp. Puts a smile on your face. With emissions-based enrichment, it feels like a GS.

Transient Enleanment
The opposite of Transient Enrichment. How's that for sidestepping the answer? Seriously though, the two terms are actually the same term, but different signs. You know, one is positive and the other negative. Generally the two are collectively referred to as Transient Fuel.

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Old 06-30-2011, 09:59 PM   #95
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Yes he has posted a lot of good info.
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Old 06-30-2011, 10:54 PM   #96
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The important info missing from this table is, up to what steady throttle opening the ecu operates at closed loop. 5%, 20%, 100%?
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Old 07-01-2011, 10:17 AM   #97
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Not sure of the meaning of the question. In closed loop the oxygen sensor is in the loop and will override the other sensors. I think the target AF is 14.7, so that is what the oxygen sensor will try to get back to.

It is not instantaneous. It takes a while for the sensor to evaluate AF and make adjustments. That is one of the reasons these modules work. Until the analysis is done and corrections made, the bike is actually in open loop and they are doing their magic. I suspect, but don't know, going from open to closed is not done suddenly. Makes sense to me that it is more gradual, in order for the oxy sensor to evaluate AF while it is being done. Any other way would result in jerky behavior and noticed by the rider.

You can get a sense of what is going on, by going to the instant gas economy feature on the bike. Fun to watch the influence throttle inputs have on economy.

On a closed trailing throttle, you will see some mileage up to and over 100mpg which makes me think the systems works just like the big GS, in that fuel is actually turned off until the bike gets back to 1,700 rpm.

However it works, it appears to be pretty sophisticated and is one reason for me to steer away from some of the other "cures". Substituting other map readings, looks like it would take an awfully lot of Dyno work in order to cover all the situations that the bike would run into in the real world.

The other "cure" is to just run an ecu with pre programmed rates, DN how that works in the real world either, but is sure to effect gas mileage. Not something I would want to do until the warranty period is over.
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Old 07-01-2011, 11:48 AM   #98
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Quote:
Originally Posted by itsatdm View Post
Not sure of the meaning of the question. In closed loop the oxygen sensor is in the loop and will override the other sensors. I think the target AF is 14.7, so that is what the oxygen sensor will try to get back to.

It is not instantaneous. It takes a while for the sensor to evaluate AF and make adjustments. That is one of the reasons these modules work. Until the analysis is done and corrections made, the bike is actually in open loop and they are doing their magic. I suspect, but don't know, going from open to closed is not done suddenly. Makes sense to me that it is more gradually, in order for the oxy sensor to evaluate AF while it is being done. Any other way would result in jerky behavior and noticed by the rider.

You can get a sense of what is going on, by going to the instant gas economy feature on the bike. Fun to watch the influence throttle inputs have on economy.

On a closed trailing throttle, you will see some mileage up to and over 100mpg which makes me think the systems works just like the big GS, in that fuel is actually turned off until the bike gets back to 1,700 rpm.

However it works, it appears to be pretty sophisticated and is one reason for me to steer away from some of the other "cures". Substituting other map readings, looks like it would take an awfully lot of Dyno work in order to cover all the situations that the bike would run into in the real world.

The other "cure" is to just run an ecu with pre programmed rates, DN how that works in the real world either, but is sure to effect gas mileage. Not something I would want to do until the warranty period is over.

You talk sense. But in motorcycle injection systems, closed loop operation does not apply to any throttle opening. At large throttle openings the systems revert to open loop, ignoring the O2 sensors. Maybe the F800 is an exception to that rule. In any case it will be interesting to know.
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Old 07-01-2011, 11:55 AM   #99
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Originally Posted by itsatdm View Post
On a closed trailing throttle, you will see some mileage up to and over 100mpg which makes me think the systems works just like the big GS, in that fuel is actually turned off until the bike gets back to 1,700 rpm.

However it works, it appears to be pretty sophisticated and is one reason for me to steer away from some of the other "cures". Substituting other map readings, looks like it would take an awfully lot of Dyno work in order to cover all the situations that the bike would run into in the real world.

The other "cure" is to just run an ecu with pre programmed rates, DN how that works in the real world either, but is sure to effect gas mileage. Not something I would want to do until the warranty period is over.

When it comes to sensors a reading is a reading. For a throttle position sensor closed is closed. If the TPS sensor is reading 0.00v then, yes of course there is no gas being called from from your wrist. If it is reading 2%, 5% or 10% then some sort of a fuel map is involved.

I am not convinced that the o2 sensors "take a while." I run a Bazzaz unit on my trackbike and you can turn on teh "track operating point" feature and watch it move from cell to cell as it highlights the cells beign used in the fuel map. 500 rpm incriments to redline and 0, 5, 10, 20 to 100% on the TOS. Picture a spreadsheet with 12 colums and 20+ rows. It also tracks the AFR in real time. If there is a lag time it is miliseconds. Oh and if it is a bosch wide band 02 then it is the same sensor that I use on that bike.

If as claimed the bike switches between open loop (no O2/Lambda sensor readings used) and closed loop (i.e. using the O2 sensor readings) to calculate the fuelling logarithm in real time then the only difference will be that the open loop map (have to guess this is the standard base map) is not being modified by the ECU for real time emissions readings via the sensor. All the 02 sensor does is read how much oxygen is in the exhaust gas. That's it, nothing more.

If it is switching it is changing things in miliseconds to match the firing order. RPM = 5000 x 60 seconds in a min means it is squirting fuel through the injector 300,000 times per min. or said another way 5,000 per second it is adjusting the fuelling based on what your wrist is asking it to do + all the different sensors and inputs.
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Old 07-01-2011, 01:10 PM   #100
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One of the sensors is the TPS, so obviously when it changes position the bike goes into open loop. I thought I was clear, but if not, I am now. I don't agree that it can't go back into closed loop at static throttle under light load. It can be programed to do that and other sources agree that it does.

Gankplank, are we talking apples and oranges here? The oxy sender is giving a signal to the ECU. What purpose would it have if it didn't have an effect on the signal the ECU is sending to the injectors on this bike. I don't know what type of ECU you are talking about.

There are a couple of ways to modify input. You can program your own and use data to make changes to the ECU. You modify the AF data in the ECU and rely on the sensors to pick the right one. Or the case of these modules you can modify the signal to the ECU of the sensors.


I am a Layman here. If anyone knows exactly how this F800gs system works, I am all ears.
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Old 07-01-2011, 01:13 PM   #101
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one of the sensors is the tpu, so obviously when it changes position the bike goes into open loop. I thought i was clear, but if not, i am now.
tpu =?
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Old 07-01-2011, 01:38 PM   #102
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Now we are nitpickingTPS Throttle Position Sensor.
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Old 07-01-2011, 02:07 PM   #103
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I've mentioned it before, but I'll mention it again. It's long (like Lord of the Rings Trilogy long) but the thread "Hotrodding the GS" has a great discussion of how these Bosch Motronic ECU behave.

While I don't know Poolside personally, I think he establishes his bone-fides as someone that is not a laymen with regards to this topic.
Quote:
Originally Posted by Poolside View Post
...
For the past 25 years I've worked as a designer of Industrial and Automotive electronics. I know what it takes to make a motor run properly, and I know what must be changed for the motor to pass EPA.

Because of my understanding of combustion, and experience with the firmware algorithms that EFI systems use to operate, I know how to optimize and tailor the various inputs or sensors to the EFI to make the boxer motor run better, to make them run the way they are supposed to.

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Old 07-01-2011, 03:32 PM   #104
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I have read all of his posts. If I have said something in conflict with his posts, point if out for me. I am not a programmer and I am stealing info from other sources. My expertise is evaluating the info and the sources and drawing conclusions. That and I think I know which questions to ask now.
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Old 07-01-2011, 03:37 PM   #105
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Originally Posted by itsatdm View Post
If I have said something in conflict with his posts, point if out for me.
No conflict at all. I was just trying to provide reference to details that are coming from someone with specific industry experience for the doubting Thomas's.
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