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2004 R1150RT Wideband O2 Sensors

The computer and O2 sensor will sense and analyze the rich condition produced by the increased fuel pressure and lean the mixture.
Oops -- RB beat me to it!

From what Roger has been posting, that is not the case if you have the LC-1/wideband O2 sensor installed as well -- the engine computer will adapt around the target AFR set by the LC-1, not around its "built-in" 14.7 target.
 
Very interesting findings on the higher fuel pressure. Not quite sure how you bypassed the existing pressure regulator from your photos though.

I was following a thread over on ADVRider last year about swapping pressure regulators. A few riders swapped out their 11XX fuel pressure regulators (43 PSI) for a K bike regulator (50 PSI) with positive results. Doing this eliminated surging on a few bikes and increased acceleration performance.

The biggest roadblock was the amount of stuff you have to remove to get at the pressure regulator and swap it out. You have to lift the tail to get at it. A fellow named StepToe stated it was possible to do it without removing the whole back end of the bike but looking at my RT I can't imagine getting in there any other way.

I think I will try out the regulator idea when it's time for a spline lube.
 
Put hoses with QDs on the input and output of the regulator and then plugged it in series with the fuel return line.

The 3.5 would be good but lifting the tail was too big a project.
 
Someone asked me the other day to take a test ride with fuel pressure set to 52 psi, Motronic reset and in Open Loop mode (Wideband O2 sensor unplugged). I got out yesterday and made the run.

My report is simple, the bike runs great--smooth, good power, very responsive to throttle from 2000 RPM or so on up, even in 4th gear. A lot like the Closed Loop test rides at 52 psi and Wideband O2 set to 13.8:1. It's not really a surprise to me that it ran well in Open Loop. But I want to point out one thing: because I had the Wideband O2 installed, I knew that my setting of the fuel pressure was producing the enrichment I was looking for. Without the Wideband O2, you can crank up the fuel pressure, but you can't say for sure where you are with the enrichment.

If you go back earlier in this thread to here: Open vs Closed Loop, notice how much flatter the Closed Loop curve looks and how much tighter the histogram distribution of AFRs is in the smaller plots.

The same thing happened yesterday when I rode at 52 psi, reset Motronic, Open Loop. The range of AFRs, rather than being tightly centered on 13.8:1 where mostly around 14.3:1 and 13.3:1 (the two horizontal dashed lines in the plot below). My educated guess is that this is how the Motronic tries keep the Catalytic converter running even if the O2 sensor is dead. Normally in Closed Loop, with a stock sensor, the Motronic runs fueling a few percent above and below 14.7:1. (Snooze alert: The reason for going to the lean side of 14.7 is to allow Oxygen to recharge the Cerium in the three way converter.) So now, Open Loop the Motronic makes big moves in the fueling, still hoping to create a lean-of-14.7/rich-of-14.7 scenario. This way too rich/way to lean is a sort of limp-home-mode. (It's noteworthy that this will be how many PowerCommander and Techlusion curves would look if anyone plotted them.) I think it is very likely that this causes more fuel consumption than the Closed Loop case.

So here is the Open Loop 52 psi plot with all its "wildness".

open52psireset.jpg



My favorite configuration remains:
LC-1 set to 13.8:1 with Fuel Pressure boosted to 52 psi (for E10 fuel).
 
It won't revert. Let me explain.

By using a Wideband O2 sensor and programing it to 13.8:1 is what keeps the motronic from leaning the mixture back to 14.7:1. It is the combination of Lc-1 and fuel pressure that keeps it Closed Loop and richer.

If you look at the earlier charts you can see the the combo keeps conditions set as programmed indefinitely.

That is correct, however the LC-1 doesn't stop the Motronic from functioning, it merely monitors and modifies the input signal from the the new wideband sensor and sends it on to the Motronic. The Motronic still monitors the throttle position sensor (TPS), crank position sensor (CPS) and O2 sensor, so that it can inject an appropriate interval of gas into the manifold at two appropriate times.

Motronic is blind to fuel pressure. The LC-1 only modifies the O2 sensor signal to your programmed setting, fooling the Motronic to make the mixture richer or leaner...if I remember correctly you've settled on 13.8.

Now you've introduced the variable of fuel pressure(FP), and evidently StepToe has done it as well. In order to inject more fuel into the engine the stock Motronic opens the injector, which is just a solenoid actuated valve, for a longer interval of time.

By increasing the pressure, you are now injecting a larger amount of fuel into the manifold, which will be interpreted by the wideband sensor, adjusted and sent on to the Motronic. The Motronic will then take this altered signal and increase or decrease the interval of injection to achieve the parameters programmed by BMW.

Your original LC-1 accomplished its goal of allowing you to richen the mixture to 13.8. The increase in FP is probably unnecessary to improve the fuel delivery system on your bike. But this is how we learn and push envelopes.

The fact that StepToe achieved better drivability could indicate that the programming of the Motronic is smarter than I thought it was. It may calculate engine load by using the TPS, CPS (and RPM), and O2 sensor to determine the interval of the injection necessary at a FP of 44 psi.

If this is true, StepToe may have hit on an elegant solution to the lean burn condition exacerbated by 10% ethanol fuel and lead to another possible solution. Increasing the injector volume delivery by 10% should achieve the same outcome and is much easier than replacing the FP regulator.

Anyone have a Bosch part number for the injectors?
 
By the way, StepToe's solution of using the K-bike FP regulator won't work as well in the US since our lean-burn condition is partially programmed and now partially due to 10% ethanol.

StepToe is from Britain, if I remember correctly, and doesn't have 10% ethanol in the fuel.
 
...

Anyone have a Bosch part number for the injectors?

Rather than try and square your take on this to the system I've implemented. I'll just make a couple points. Steptoe over on advrider.com was boosting pressure without shifting Lambda. This will get Adapted out over the long term. He was looking to solve a different problem than me I guess.

Your explanation is missing a key point in the Motronic operation, Adaptation Values, which I planned to write up. I will do so in the next post.

As part of rebuilding my fuel system I had the injectors out for cleaning. They are Bosch EV6 injectors, Injector Part #: 0280 155 788, 16 ohm saturating-type.

RB
 
A couple posts ago I said I would explain the connection between Closed Loop, Adaptation Values and Fuel Pressure increase.

There is no easy way to think of or explain the full operation of the Motronic. That is especially true when you get into one of the Motronic MA 2.4 strongest abilities: Value Adaptation.

Assuming you maintain Closed Loop operation by keeping a valid O2 sensor in the system, there are many examples in this thread which show the following:

1.) If you leave the stock O2 sensor (programmed by physics to an AFR of Lambda = 1 which is 14.7:1 for gasoline) through the process of Adaptation the Motronic will, over time, create Adaptation Values which eliminate the affect of fuel pressure changes, input air temperature changes, etc. In other words it reverts to the AFR dictated by the O2 sensor--including during Open Loop operation by applying the learned adaptation values as corrections.

2.) If you put in an O2 sensor that shifts Lambda (in my case programmably to Lambda = 0.94 which is 13.8:1 for gasoline) you don't require a change to air temperature or fuel pressure. But a pressure increase can still have value as you will see.

The reason for the behaviors in 1.) and 2.) are because the Motronic can use its O2 sensor to learn in Closed Loop corrections to the Open Loop Fuel Map. For example, the Fuel Map value for 3500 RPM and 6 degrees on the TPS might be 3.5 milliseconds. In Closed Loop, the Motronic and O2 sensor might "see" that it actually takes 3.675 milliseconds. If that actual value is the case over the long term, the motronic might start with a 1% Adaptation Value, that creeps its way to a full 5% over time. This is a simple picture of how Adaptation Values get learned. (When you pull Fuse 5 or a battery lead they get erased.)

In case 2.) the Motronic must create Adaptation Values like the ones below (I can't find the R1150 Bosch/BMW's adaptation table but the table illustrates the point). Because the stock Fuel Map values in the Motronic equate to lambda = 1 for gasoline but Lambda = 1.04 for E10 fuel and because I've programmed lambda to 0.94, the Adaption Values inside my Motronic will be about +10%. These values will be in something like the 4 X 4 matrix at the top of the table below.

A few things about Adaptation values: they bridge the gap between the stock Fuel Map and reality as defined by the O2 sensor; it is hard to drive in Closed Loop in some of the areas of the adaptation map, e.g. high manifold pressure or high RPM; and these values can take hours of driving to build up.

So the reason to boost the fuel pressure or move the IAT sensor colder, is to bring the stock Fuel Map closer to the final AFR so that the Adaptation Values can be small. One last note, the Fuel Map might be a 16 X 16 table where the Adaptation Map might only be 4 X 4, much coarser. So all things considered there is real value to getting the Fuel Map shifted close to the final values.

An adjustable fuel pressure regulator does a great job of invisibly aligning the Fuel Map and a Wideband O2 sensor, and does a great job of taking care of the extra fuel needed for E10.

ftcoc2.png
 
Here is another Adaptation strategy.
97800813.jpg


This is interesting because it shows 3 types of Adaptations: a short term fuel trim (Lambdaintegrator) and two long term fuel trims. One long term fuel trim is additive for short injector pulses the other is multiplicative for longer fuel pulses. This is from an early 2000s BMW car, I believe.

I've posted this and the prior example not to say I've figured out which strategy BMW used on these Motronic based bikes but to show different ways that the data I've measured can be accomplished.
 
I've now logged about 500 miles on my add-on fuel pressure regulator (FPR) and LC-1 combo--no BoosterPlug or other changes to my stock R1150RT.

The LC-1 and FPR are tuned for a gasoline AFR of 13.8:1 using E10 fuel. The mileage includes almost 100 miles between 70 and 85 mph. Lambda on the LC-1 is now set to 0.94. And the fuel pressure regulator (FPR) is set to 52 PSI, correcting Open Loop for both the change in Lambda and the leanness of E10 fuel. As setup now, I would say that the Boxer engine is as responsive, smooth and powerful (for the bike's weight) as any engine I've owned. It's interesting to duck down below the windscreen between 60 and 80 mph in 6th gear, listening to the engine it's very comfortable at these speeds, powers and RPMs (3000-4000).

On the last series of Open Loop tests that I made, I attempted to set things up in the garage while on a conference call. Cradling the phone on my shoulder, taking the bike off the center stand and dodging some stuff piled on the floor in front of the bike led to a slow motion tip-over and a couple of deep scratches on the windscreen as it hit an adjacent bicycle. I've bought a Micro-Mesh kit and some coarser (320 & 600) sandpaper. That seems to be going pretty well. Scratches are gone, polishing it up.

When I have time, I'll take a look at all the speeds and RPMs where the Motronic is Closed Loop, at least as much as I can cover.

RB
 
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I got out today with the GS-911 attached and a PC in the Top Case for a 100 mph run up a section of posted 50 mph highway that runs through a flat swamp nearby. I didn't get past fifth gear before running out of highway. I continue to operate at 52 psi fuel pressure and a mixture of 13.8:1 no BoosterPlug or any other modification to my '04 RT.

The idea was to see when and where the Motronic runs the Closed Loop program. I've got some charts coming but here are a few observations. Keep in mind that the max 95HP is at 7250 RPM.

--Closed Loop was operational at 100 mph (The engine seemed very smooth here)

--Closed Loop was operational in 2nd, 3rd, 4th gears at nearly 6500 RPM.

--Closed Loop was operational at 48 degrees throttle (80 degrees is wide open) going 100 mph

--In 3rd gear, while accelerating to 70 mph the Motronic was Closed Loop a lot of the time. Same in 4th gear to 90 mph.

--In 5th gear, WOT Motronic stayed mostly Open Loop from 65 mph to 100 mph. But as soon as I "relaxed" the throttle to about 3/4 open at 6400 RPM, Closed Loop kicked in. Amazing!

Given the amount of time and operating areas where the Motronic will enforce lean Closed Loop, I think it gets easier to see the advantages of mixture richening by using a Wideband O2 to shift Lambda from 1 to something less--0.94 in my case.

--At 6000 RPM & WOT the injector was on for 7.2 milliseconds. One revolution of the engine only takes 10 milliseconds at that RPM. At 7250 RPM (max horsepower) each revolution is only 8.3 mS. The injectors would be open 90% of the time!

(The air temperature was 90F today; had it been 20F the 7.2 mS injector pulse would lengthen to 8.1 mS. Were I to boost my fuel output using a -20C air-temp shifter on a 20F day, that pulse would lengthen to almost 8.6 mS. More than 100% on-time! Fuel pressure is a better method for boosting injector output (compared to IAT shifting or PCs or Techs) since it doesn't require the injector pulse to be lengthened.)

That's the raw data. I'll try and post a chart tomorrow after I've thought about it further.
RB
 
I thought some might like to see the chart but I don't have time to provide the detailed annotation yet. Briefly, the Green line has two states: Closed Loop program running is the HIGH state but forget the label on the right side of the graph, it's just used to shift the 1/0 to the top of the chart. The red and blue curves use the left axis labels.

There are 6 RPM peaks. They are gears: 1st/2nd, 2nd, 3rd/4th/5th. I'll note them on the photo later when I get time for further detail but for now the comments in the prior post apply to this chart.

In first gear, Closed Loop seems to stop at 4000 RPM. In Neutral (not on the chart) Closed Loop ends around 3000 RPM, or maybe lower.

As I mentioned in the prior post, note that in 5th gear, 6350 RPM and 45+ degrees of throttle, the Motronic goes Close Loop!

closedlooprange1.jpg
 
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How the Motronic handles spark advance has been something of interest. When the data two posts back was collected, I also collected ignition timing data, plotted below, for reference and for those who are interested. This data is for the Motronic MA 2.4, Pink Coding Plug.

Unlike fueling which can be modified externally, spark advance is under the control of the Motronic's internal program so can't be modified without an ECU chip replacement.

The charts below show spark advance compared to RPM and to throttle angle. In the RPM chart you can see that advance is increased with RPM, reaching a maximum of about 43 degrees above 4000 RPM.

In the TPS chart you can see that the maximum advance is only for throttle angles below 18 degrees (80 degrees is WOT), and is then reduced for wider throttle angles. From 50 degrees to wide open throttle the advance is limited to 20 degrees.

The other thing worth noting is that while the spark is advanced with RPM up to certain throttle angles, there are a lot of points scattered well off the curve. This shows that there are other factors that the Motronic uses in its timing calculations.

sparkadvancescatter.jpg
 
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Although I'm no authority on spark advance, I did receive my early introduction to it from a Model A fire truck. This print out looks to me like a bit of Monday morning programming and could contribute to the surging and backfire issues. I believe it would be counter productive to decrease the advance as the throttle angle increases. What's your take?
 
Wait...The charts don't match. When you try to use degrees advance to correlate the two charts, the results don't make sense. Are these two different runs under different conditions?
 
It's very interesting data to me and the charts are indeed from the same run. If you go back to the post with the closed loop data you can see that WOT happens before peak RPM. So the sequence is open the throttle aggressively, get RPM to start building, relax the throttle some, reach peak RPM, stabilize the throttle.

It turns out that it is the norm in a spark table for advance to increase with RPM but on the TPS axis of the table the advance initially grows to about 1/3 to 1/2 throttle and then the advance is reduced. One reason is that at WOT the mixture is pretty rich and the flame front velocity is faster in richer mixtures, leading to less advance required.

Here is a link to a good description and a table: Spark Timing Table
 
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This brings up a whole host of questions. I think the graphs would be easier to interpret if you did a few one-gear-runs...say 2nd gear at a gentle throttle and WOT. And for graphs, show open-closed loop, superimposed on the timing advance vs rpm, vs tps angle and also mixture.

The reason I say 2nd gear is that you can do a takeoff to redline all in the same gear. I wonder if the advance curves and advance transitions as the mixtures richen would be more apparent.
 
This brings up a whole host of questions. I think the graphs would be easier to interpret if you did a few one-gear-runs...say 2nd gear at a gentle throttle and WOT. And for graphs, show open-closed loop, superimposed on the timing advance vs rpm, vs tps angle and also mixture.

The reason I say 2nd gear is that you can do a takeoff to redline all in the same gear. I wonder if the advance curves and advance transitions as the mixtures richen would be more apparent.

Since the GS-911 takes data sequentially, what I'd really like to find is a 3D Scatter Plot function for Excel. That would make my life much easier. For now these plots are the best I can come up with and they do open a window into the Motronic's spark timing world. Hopefully I'll find a 3D scatter tool.
 
Is it just me or does anyone else see the possibility of getting more power at using 5/8 throttle if RPMs are low, versus WOT?
 
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