Booster Plug

[Scotto336]

My recently acquired 2019 RT seemed very stumbly (new word?) when pulling away compared to my 2016 R1200R.  Getting a smooth pull away seemed to involve throttle hand and clutch gymnastics that weren't needed on my R.  My thinking was that it's related to leaner fueling mandated for newer bikes.  Whatever it was, adding a Booster Plug fixed it.  Very smooth pulling away now with no thought or gymnastics.  I have to say, putting the Plug on an RT is a pretty serious endeavor in terms of time and energy.  The fuel tank needs to be moved back so most Tupperware needs to come off.  It's a bit more involved than changing an air filter, but mine was due for a filter change so I went ahead with it while the stuff was off.  The bike's fueling seems smoother throughout the range of throttle twisting.  I have no idea if it makes more HP, but I would say it's worth it overall if your ride suffers from lean fueling symptoms that bother you.  That's why I did it.  I won't be adding one to my R because the fueling seems fine on that.   

[duckhawk64]

I have no issues with mine doing that. 17k miles. I don't warm it up. No ethanol fuel and  two jugs of the techron fuel injector cleaner run through the last 2 tanks before the winter storage tank. I ride it... assertively.

[Randyjaco]

I haven't had that problem with my 17 RT, but a booster plug provided a major improvement with my previous f800st. It was a cheap solution to that problem.

[Boxflyer]

Sorry to be an opposing view, but here is a post by someone who actually did some extensive testing on this "type" of temporary adjustment device that tries to "fool" the fueling in the ECU.
https://forums.bmwmoa.org/threads/boosterplug.93508/post-1147007

I don't recommend this type of aftermarket add on device, since the engineers at BMW have written into the code of the ECU to correct the fuel/air ratio based on the detected fuel being ethanol or non-ethanol.

The fueling will be back close to what it was within a tank or 2 of fuel.

 

Brad

[Scotto336]

Time will tell Brad.  I'll let you know for sure, wherever it lands.  So far so good, but I've only put about 60 miles on thus far.  I need to put on more miles. I will certainly know if it goes all the way back to the original fueling when pulling away.  I'll also follow up with the cam timing adjustment you suggest once this experiment is completed.  Don't want to throw another variation into the equation until then.   

[dirtrider]

59 minutes ago, Scotto336 said:

Time will tell Brad.  I'll let you know for sure, wherever it lands.  So far so good, but I've only put about 60 miles on thus far.  I need to put on more miles. I will certainly know if it goes all the way back to the original fueling when pulling away.  I'll also follow up with the cam timing adjustment you suggest once this experiment is completed.  Don't want to throw another variation into the equation until then.   

Afternoon Scotto

 

Your thread is in the wethead forum but your 2019 is most likely a 1250. (is it a 1250?)

 

If it is a 1200  wethead then for sure the Booster Plug will get learned around by the fueling control then it's altered input eventually disregarded.  

 

If you in fact have a 1250 then those are different as unlike the earlier BMW boxers the 1250  engines have wide band o2 sensors. I haven't done any testing on the 1250 wideband system as far as IAT (Intake Air Temperature) spoofing  long term effect but there is a chance that the wide band system is more flexible in using the IAT for closed loop fueling as it isn't forced to stick with a single Lambda factor. 

 

The older narrow band systems didn't really look at the AIT once in closed loop for fueling control as closed loop (fueling) was just between the o2 sensors &  fueling computer. I haven't ever looked into it but I suspect that the narrow band systems did look at the IAT a little for some of it's light throttle spark control.  

 

Even on the older narrow band systems it will drop out of closed loop control at moderate to heavy throttle inputs & at anything more than light throttle-up position changes (this area is where it typically used the learned fueling adaptives). So with an AIT spoofer you might see a little better fueling at moderate to heavy throttle up (that is until it relearns the new o2 based adaptives)

 

 

[Stiggy]

I would assume that leaner and cleaner fuel regulation with the newer motorcycles is to blame. My '17 1200 RT has never exhibited any erratic behavior in take off from start, whether hot or cold.

[Scotto336]

thanks DR, and yes, it’s a 1250, so wideband.  New to the forum so sorry for wrong thread, however it does indeed have a wet head, so these names can be a bit confusing to an old guy.  I’m not an AFR control systems expert by any means but here’s my perhaps, very naïve, old guy thinking: data acquisition and processing can be very tricky business under conditions where RPM and load are changing very abruptly as with pulling away and shifting.  In these conditions, things have often changed in less time than it takes to acquire the information and act upon it.  When we look at the sun, we are actually seeing what it looked like 8 minutes ago.  That’s how long it takes for light to travel the distance.  In EFI control systems, the delay or deadtime in acquiring and reporting information is much less, but it’s a long way from zero.   There’s a good table comparing wideband AFR sensor response times in the article at this link:

https://pitpad.com/2017/05/01/response-time-matters-when-choosing-a-wideband-airfuel-ratio-controller/

So, they reported response times from about 19 to 129 milliseconds using mostly Bosch sensors.  I suspect that if we could actually sample (extremely high sample rate) and plot the actual A/F ratio under these conditions of abrupt change of RPM and load, we would see a very bumpy curve due to the systems inability to keep up and correct quickly enough.  In attempting to keep up, the system can create anomalies that can present as poor fueling.  Sometimes the harder they try, the worse it gets, especially when we are close to the edge of too lean in our efforts to control emissions.   We sometimes see this in today’s automatic transmission control systems where janky hunting occurs between “gears” in the system’s attempt at maintaining a constant RPM.  A lower fueling control system sampling and correction rate might actually present a smoother perceived  output curve.  My 2016 R (older control system tech) doesn’t have a perceived fueling problem.  I suspect that the booster plug moves things just a bit farther from the edge resulting in a perceived smoother operation.  The A/F ratio may well be corrected back to original under smoother operating conditions, I don’t know.  Whether or not the 1250 system will effectively negate the plug’s effect over time is TBD for me.  May be worth mentioning that one of the Booster Plug staff in Denmark has a Plugged 1250 GS with over 8K miles on it and says it hasn’t cancelled the Plug’s effect.

[dirtrider]

7 minutes ago, Scotto336 said:

thanks DR, and yes, it’s a 1250, so wideband.  New to the forum so sorry for wrong thread, however it does indeed have a wet head, so these names can be a bit confusing to an old guy.  I’m not an AFR control systems expert by any means but here’s my perhaps, very naïve, old guy thinking: data acquisition and processing can be very tricky business under conditions where RPM and load are changing very abruptly as with pulling away and shifting.  In these conditions, things have often changed in less time than it takes to acquire the information and act upon it.  When we look at the sun, we are actually seeing what it looked like 8 minutes ago.  That’s how long it takes for light to travel the distance.  In EFI control systems, the delay or deadtime in acquiring and reporting information is much less, but it’s a long way from zero.   There’s a good table comparing wideband AFR sensor response times in the article at this link:

https://pitpad.com/2017/05/01/response-time-matters-when-choosing-a-wideband-airfuel-ratio-controller/

So, they reported response times from about 19 to 129 milliseconds using mostly Bosch sensors.  I suspect that if we could actually sample (extremely high sample rate) and plot the actual A/F ratio under these conditions of abrupt change of RPM and load, we would see a very bumpy curve due to the systems inability to keep up and correct quickly enough.  In attempting to keep up, the system can create anomalies that can present as poor fueling.  Sometimes the harder they try, the worse it gets, especially when we are close to the edge of too lean in our efforts to control emissions.   We sometimes see this in today’s automatic transmission control systems where janky hunting occurs between “gears” in the system’s attempt at maintaining a constant RPM.  A lower fueling control system sampling and correction rate might actually present a smoother perceived  output curve.  My 2016 R (older control system tech) doesn’t have a perceived fueling problem.  I suspect that the booster plug moves things just a bit farther from the edge resulting in a perceived smoother operation.  The A/F ratio may well be corrected back to original under smoother operating conditions, I don’t know.  Whether or not the 1250 system will effectively negate the plug’s effect over time is TBD for me.  May be worth mentioning that one of the Booster Plug staff in Denmark has a Plugged 1250 GS with over 8K miles on it and says it hasn’t cancelled the Plug’s effect.

Afternoon  Scotto

 

The basic response time based on the o2 sensors input is usually not a big deal as small or slower throttle changes give plenty of time for the system to adapt using the o2 sensor input (it basically stays in closed loop).

 

On heavy, abrupt, or large throttle or load changes the system basically drops out of closed loop then reverts to fixed parameters (open loop mapping), this fixed mapping is then modified or altered by the stored fueling adaptives. 

 

This is where the learned adaptives come into play. There are short term adaptives (those are constantly changing as you ride and/or riding condition changes), these go away at key off engine stop. The long term adaptives are also learned but these are semi-permenent as they stay until they are removed manually. The long term adaptives are slowly changed/modified/fine tuned as the fueling system learns from it's sensors, especially the Lambda (o2) sensors. 

 

As I mentioned above, I haven't done any real testing on the 1250 wideband system but I have worked with a large number of wideband systems for years now. I'm betting your fueling system will slowly learn out most of the Booster Plug offset. The positive part is that wide band systems are not so fixated on a tightly controlled Lambda so even if it learns it's way around most of the Booster Plug off-set the wide band's more precise fueling control might still allow it to run very slightly richer in certain throttle/load/RPM ranges. 

 

My basic takeaway on the 1250 wide band system even needing a Booster Plug to run correctly is that it is covering for something else in the fueling control/mechanical system that needs adjusting, or repairing, or at least understanding. The 1250 bikes run pretty darn good with no additional spoofing needed.  

 

Does your 1250 have the latest firmware in it? There were some updates over time so that might be worth looking into as well as camshaft & ignition trigger timing being correct. 

[Scotto336]

Thanks D.R., that's very helpful in my understanding.  It was in for driveshaft inspection a few weeks back and they did a couple of  updates at that time.  I'll put some more miles on and see what happens.  On another note (wrong forum thread and topic),  it also makes the much discussed jangly noise under low rpm load.  I don't think it's detonation but it is a bit annoying.  It's not Ducati dry clutch loud as you have mentioned, but I do hear it with earplugs in.  Most seem to point to the throttle body butterfly.  I'm clueless on this.

[Scotto336]

Just to follow up,  I have about 3 tanks of gas run through so far and the improved performance is still there in full force.  It's especially noticeable in the smoothness while pulling away from a stop.  If I had approached this more scientifically I would have done the valves and cam timing first, but I lack the cam tools.  Brad generously offered to do that for me for free but he's 4 hours away and the weather was not good.  My bad on that front.  Again, this is a 1250 and all of the posts and info indicate that this would be of no value for a 1200 due to relearning.

[Dave_in_TX]

On 3/14/2024 at 4:43 PM, Stiggy said:

I would assume that leaner and cleaner fuel regulation with the newer motorcycles is to blame. My '17 1200 RT has never exhibited any erratic behavior in take off from start, whether hot or cold.

I haven't experienced any erratic behavior on takeoff from my 2020 or 2023 GS so it may be something else.

[JCtx]

My 2020 rides perfectly too. However, it idled like crap when it was cold, to the point of almost stalling. That was the only thing I didn't like at all. Oh, and I couldn't hear  the exhaust at low rpm either. Somebody mentioned removing the exhaust valve servo and using a 'servo buddy' to avoid a CEL was the answer, and IT WAS. I didn't think it'd work, but I also wanted to hear my engine/exhaust when taking off stop lights, and now I have perfect idle hot or cold, and engine sounds a lot nicer. Turns out that valve is not for TQ control at all, but for Euro noise control. It's closed until 2,500 rpm or so, when it fully opens. And takeoffs are actually smoother now, so I highly recommend that little mod. And no errors of any kind.

[alexvtr]

On 4/11/2024 at 9:48 AM, Scotto336 said:

Just to follow up,  I have about 3 tanks of gas run through so far and the improved performance is still there in full force.  It's especially noticeable in the smoothness while pulling away from a stop.  If I had approached this more scientifically I would have done the valves and cam timing first, but I lack the cam tools.  Brad generously offered to do that for me for free but he's 4 hours away and the weather was not good.  My bad on that front.  Again, this is a 1250 and all of the posts and info indicate that this would be of no value for a 1200 due to relearning.

I used a similar gadget (recyclizer) on my previous RT (Hexhead) to great results over 2 years of riding.

I'm tempted to go this way again on my 1200 Wethead to improve city / bumper-to-bumper / off-idle smoothness.

 

I'd greatly appreciate if you'd please share some more results after a bit more of riding.

TIA!

[dirtrider]

Afternoon alexvtr

 

You definitely don't want to use something like the "recyclizer" on a wethead, as that looks like just a simple inline resistor (no secondary NTC sensor). 

 

The temperature curve on the wethead is not a linear curve so using a non-temperature-sensing (series resistor) will only be in the ballpark in a small temperature range. In fact it could be so far out of expected that the fueling computer disregards the errant temperature string input at all but a narrow band of input.      

 

Even things like the "Booster Plug" won't do much of anything when operating in closed loop (most warm engine light to moderate throttle conditions & light acceleration from a stop).  And at least the "Booster Plug" incorporates a secondary NTC temperature sensor to retain a somewhat proper non-linear temperature curve. 

 

To really get much of anything useful from a "Booster Plug" you pretty well need to disconnect the o2 sensors so it can't just learn around the spoofed temp input. But you REALLY do not want to do that on a wethead. 

[Skywagon]

Not sure why you would want to fiddle with wethead idle anyway. They are very smooth unless something is off. The early 1100 issues are not present in the wetheads….No surging, no bad idle. 
 

Milage is also very good. 

[JCtx]

My 2020 basically has perfect fueling now. The only slight disappointment initially was a low rpm slight 'stumble', which was a lot worse on cold starts, almost to the point of stalling. But it was completely eliminated when somebody suggested removing the exhaust valve's servo motor (along with installing a 'servo buddy' to prevent a CEL), which is there just for Euro noise emissions, not for torque optimization, like the similar Yamaha valve (I owned an MT-10). Our valve is almost fully closed upon start-up, and fully opens at 2K rpm, so it literally chokes the engine up to that rpm. The added benefit is I now can hear the engine when taking off (with ear plugs and the Akra), which I couldn't before, plus it sounds a lot nicer too. So it was the best ($65) mod I did. Next one was the recent $151 updated left side chain tensioner, which made my bike sound like a swiss watch. Ha ha. It's incredibly quiet (for a boxer twin) now, with the sound of mechanical perfection, rather than a bunch of nuts loose inside the engine, like before. Glad I read about that upgrade.

[Scotto336]

Did you also eliminate the valve or just leave it in open position?

[JCtx]

The valve has a pretty hefty spring that keeps it open by default, so no need to mess with it. It'd be very involved to remove it anyway; not worth it. Plus leaving it alone allows the mod to be fully reversed if desired (for a future owner), which I always like to do. But did remove the servo and cables (they're in a box now, along with stock levers, muffler, etc), and installed the 'servo buddy' in that space. I highly recommend doing that, if not done already. And absolutely zero issues with CELs, so that electronic gizmo does the job well. Probably a simple resistor inside, but rather buy something that I know will work for sure. The tensioner is also super simple to replace, but make sure to put your hand below, so it doesn't shoot down to the floor -spewing oil drops- when no more threads are left. Ha ha. And torque new one to 23 ft/lbs.

[Scotto336]

Thanks JCtx!  Think I'll do the same.