Dual LC-1s Installed on Camhead

[Dann]

If I understand correctly, this means that things like the "Booster plug" that tricks the temperature sensor will only be effective until the ECU adapts and puts everything back the way it was?

 

[roger 04 rt]

Okay, let's cut to the chase. Does your system work on the camhead or not?

I can't follow the techno-speak.

Cutting to the chase, I'm not sure which "system" you mean but the answer's are Hexcode SA's GS-911, Innovate Motorsports's LC-1 & 2, and Nightrider's AF-XIED all work on the camhead. The LC-1 & 2 (with customization by the user) and the AF-XIED both shift lambda and add fuel in a precise way.

If I understand correctly, this means that things like the "Booster plug" that tricks the temperature sensor will only be effective until the ECU adapts and puts everything back the way it was?

You have it exactly right. Let's say both cylinders were exactly equal. A simplified analysis would show, after riding a stock bike for a while, the multiplicative trims would be 1.00. If you then added a BP and rode for several tanks of fuel, the multiplicative trim would decrease to about 0.94. In reality, each trim is different on a stock bike.

If you ran that same ideal stock bike on pure gas and got trims of 1.00 and then switched to fuel with 10% ethanol the trims would average 1.04.

This bike, at WOT and with AF-XIEDs adding about 6% fuel averages an increase to 1.08 on the right cylinder and 1.03 on the left cylinder, for an average increase of 5.5%. You could reduce each trim by 6% to estimate this bike in stock configuration.

 

[Hodadd]

Cutting to the chase, I'm not sure which "system" you mean but the answer's are Hexcode SA's GS-911, Innovate Motorsports's LC-1 & 2, and Nightrider's AF-XIED all work on the camhead. The LC-1 & 2 (with customization by the user) and the AF-XIED both shift lambda and add fuel in a precise way.



You have it exactly right. Let's say both cylinders were exactly equal. A simplified analysis would show, after riding a stock bike for a while, the multiplicative trims would be 1.00. If you then added a BP and rode for several tanks of fuel, the multiplicative trim would decrease to about 0.94. In reality, each trim is different on a stock bike.

If you ran that same ideal stock bike on pure gas and got trims of 1.00 and then switched to fuel with 10% ethanol the trims would average 1.04.

This bike, at WOT and with AF-XIEDs adding about 6% fuel averages an increase to 1.08 on the right cylinder and 1.03 on the left cylinder, for an average increase of 5.5%. You could reduce each trim by 6% to estimate this bike in stock configuration.

I wasn't trying to be a smart aleck, but I've been following your threads for years here and on ADVRider, so I know you've been working on a system for assisting the fueling on many different models of beemers. Hence, my confusion.

 

[roger 04 rt]

I wasn't trying to be a smart aleck, but I've been following your threads for years here and on ADVRider, so I know you've been working on a system for assisting the fueling on many different models of beemers. Hence, my confusion.

Not a problem, I wrote both answers in a hurry. My take-away from this new data coming from the GS-911 (additive and multiplicative trims) is that all the empirical data taken using LC-1s and LC-2s has been proven correct by this new direct set of reports. Until now I had to set up experiments, measuring AFR with the LC-1 and observe the effects of the "trim" values on AFR. Now for the BMSK, it directly reports that things are working the way the experiments (and Bosch BMW documentation) suggested they were.

As more GS-911 data comes in, we will probably get a much better idea of the scope of trims and the variation in motorcycle to motorcycle and left-right cylinder variations. Knowing left-right variations on the R1200 will give us an idea of how big the variations are likely to be on the R1100 and R1200. I don't think many R1200 riders with GS-911s will study the trims so the data will unfold slowly.

 

[Ponch1]

Not a problem, I wrote both answers in a hurry. My take-away from this new data coming from the GS-911 (additive and multiplicative trims) is that all the empirical data taken using LC-1s and LC-2s has been proven correct by this new direct set of reports. Until now I had to set up experiments, measuring AFR with the LC-1 and observe the effects of the "trim" values on AFR. Now for the BMSK, it directly reports that things are working the way the experiments (and Bosch BMW documentation) suggested they were.

As more GS-911 data comes in, we will probably get a much better idea of the scope of trims and the variation in motorcycle to motorcycle and left-right cylinder variations. Knowing left-right variations on the R1200 will give us an idea of how big the variations are likely to be on the R1100 and R1200. I don't think many R1200 riders with GS-911s will study the trims so the data will unfold slowly.

The bottom line to me is, what can I do with this? Does it make much difference to tuning the engine? In other words, what's the practical application?

 

[roger 04 rt]

The bottom line to me is, what can I do with this? Does it make much difference to tuning the engine? In other words, what's the practical application?

That's a great question, what is the practical application?

I'm torn between a couple candidates for first place. If you're fully satisfied with the way your motorcycle runs in its stock set-up there are two reasons to have access to the long term trims: 1) for problems that arise over time, the long term trims tell you how the BMSK is adapting to engine conditions--for example if both trims were 1.18, it might mean your fuel pressure was low or your intake was clogged or if one was 1.18 and the other was 0.82 you'd know there was a balance problem; and 2) knowledge of their existence would leave you satisfied that dozens of costly add-ons would not change the performance of your bike.

On the other hand if you did want to improve your bike's performance the trims can let you know if an add-on really did what it claimed. For example, if a device claimed to flow more air into the engine, the the trims would increase if more air actually entered the engine.

Long term trims are one of the most powerful diagnostic indicators but BMW and others have kept them pretty well hidden and their meaning obscure. I applaud Hexcode for digging them out and starting to report them.

 

[Rinty]

Roger: supplementary to my earlier question: Would an AF-XIED smooth out the abrupt throttle action on my '05 R1200ST?

Thanks for doing all the research on this.

 

[roger 04 rt]

Roger: supplementary to my earlier question: Would an AF-XIED smooth out the abrupt throttle action on my '05 R1200ST?

Thanks for doing all the research on this.

The key question is, has your bike been well tuned and/or are there any other problems. Richer mixtures have been shown to improve throttle response, especially at low power levels, across a wide range of BMW motorcycles. However, if you have misadjusted cables or problems with the idle stepper motors or marginal stick coils, you may not see improvement.

Unlike many other approaches, lambda-shifting really does what it claims, richenes mixtures by a small, controlled amount. Most who have used lambda-shifting to richen their mixtures report strong gains in rideability and low-end torque.

 

[Rinty]

The key question is, has your bike been well tuned and/or are there any other problems.

I think all is in order; my bike is serviced by good techs. I may just have one installed and see what happens. The abrupt throttle action is really my only nit about this excellent bike.

Thanks for this.