AF-XIED for R1200 LC

Using a manipulator on the 1250 will pose a new challenge. There is a third O2 sensor that is mounted after the cat. It probably is there to verify the effect of the cat, and the feedback to ECU will be different than from the two O2's ahead of the cat. Installing manipulators on two of the O2's only will probably throw a fault code, in which case the ECU will not enter close loop and the manipulation will not work.

I have plans to put my 1250 on the bench and check it, but that will be when riding season is at it's end. Kind of a potential winter project.:beer:

My thought is that the difficulty will depend on how many tests of the rear sensor the BMSX makes. Certainly it will look for a signal in the band of 400-500mV during Closed Loop cruising, whether it looks for a low signal during Overrun Fuel Cutoff, and a high signal during near-WOT acceleration, remains to be seen.

If I had an R1250, I’d just give it a try. But I bet if someone with an R1250 and gs-911 and wanted to test it, Nightrider would provide a test kit.
 
I think that sometimes it doesn't matter what a manufacturer will do to improve their bikes and keep them to current (responsible) emissions standards. There will always be riders who want to modify them and for 99% of our riding, usually with no real benefit, at least in the case of the 1250 which by all accounts is bang-on straight from the factory.

It won't stop people with too much time and money on their hands from trying to "tune" a 1250 though :blast.

If I were now to go ahead with any tuning on my 1200 LC, I think that the AF-XIED, from everything shared in this thread, is clearly the simplest and most likely the best option. Whilst I can see the benefits, it still plays on my conscience that in doing so, I'll be removing emissions controls in fuelling to some extent but more than that, I remain sceptical that any form of tuning is needed, at least to my own bike which is great as standard. It could be improved but it's good enough not to need improving. It could have a little more low/mid drive but imho, it has more than plenty already. If someone could convince me that it would make the bike more long term reliable, then the emissions arguments start to fade by virtue of whole life carbon footprint considerations.

This is one of the biggest cons currently in the car world where we have a plethora of "clean" tiny engined, highly stressed turbo direct injection petrols....with a lifespan likely half that of a well maintained normally aspirated larger displacement if less efficient motor. What has been found with many of these designs is that especially when cold, they dilute the oil with gasoline (Honda kicked off the whole thing with many claims in the Sattes for failing CRV I think it was engines). Result? No recalls, just a note to dealers suggesting oil changes are changed from 12K to 6K intervals, or to 3K intervals for harsh driving environments like short trips.

Ford have had major issues with their direct injection petrol buzz boxes failing prematurely too (as well as transmission issues). It's all been driven by Euro emissions regulations. Result? Higher carbon footprint due to more scrapped engines in short order and increased oil consumption.

Bikes, by and large, do not seem to have suffered the same fate. The 1250 is a prime example of just what is achievable with good engineering know how.
This assumes that all engines are equal, some are good, others not so. There are so many variables and imponderables, also what for one is tunning is simply optimising everything for another.

By extention, an engine produced most power whilst being at optimum, this then has to be changed to meet lots of competing requirements, reliability, marketing, and legislation too.

Setting up fueling/emissions to improve driveability from standard, something has to give.

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I think that sometimes it doesn't matter what a manufacturer will do to improve their bikes and keep them to current (responsible) emissions standards. There will always be riders who want to modify them and for 99% of our riding, usually with no real benefit, at least in the case of the 1250 which by all accounts is bang-on straight from the factory.

It won't stop people with too much time and money on their hands from trying to "tune" a 1250 though :blast.

If I were now to go ahead with any tuning on my 1200 LC, I think that the AF-XIED, from everything shared in this thread, is clearly the simplest and most likely the best option. Whilst I can see the benefits, it still plays on my conscience that in doing so, I'll be removing emissions controls in fuelling to some extent but more than that, I remain sceptical that any form of tuning is needed, at least to my own bike which is great as standard. It could be improved but it's good enough not to need improving. It could have a little more low/mid drive but imho, it has more than plenty already. If someone could convince me that it would make the bike more long term reliable, then the emissions arguments start to fade by virtue of whole life carbon footprint considerations.

This is one of the biggest cons currently in the car world where we have a plethora of "clean" tiny engined, highly stressed turbo direct injection petrols....with a lifespan likely half that of a well maintained normally aspirated larger displacement if less efficient motor. What has been found with many of these designs is that especially when cold, they dilute the oil with gasoline (Honda kicked off the whole thing with many claims in the Sattes for failing CRV I think it was engines). Result? No recalls, just a note to dealers suggesting oil changes are changed from 12K to 6K intervals, or to 3K intervals for harsh driving environments like short trips.

Ford have had major issues with their direct injection petrol buzz boxes failing prematurely too (as well as transmission issues). It's all been driven by Euro emissions regulations. Result? Higher carbon footprint due to more scrapped engines in short order and increased oil consumption.

Bikes, by and large, do not seem to have suffered the same fate. The 1250 is a prime example of just what is achievable with good engineering know how.

In piston aviation, where the range on a tank of fuel is a key metric, and where engine longevity and maintenance costs are also key considerations, there has been a somewhat recent development: Lean-of-Peak (LOP) operation. The idea is: balance all cylinders’ AFRs and run 10% or so leaner than 14.7 (peak EGT).

The benefits are higher MPG, cooler EGT and CHT (cylinder head temp), and a much cleaner burn. And yes, exhaust and cylinder head temperatures go down with a mixture leaner than 14.7:1.

You could achieve this on our bikes by using dual LC-2s tuned to lambda=1.1 (10% lean). In fact I’ve tried that on my R1150GS and it works fine with a little boost to the idle screws. Horsepower is down some, roll on acceleration is weaker but Cruise is pretty good. I can’t stand riding like that but it works and my MPG is several % better in cruise than with lambda=0.92.

My 2017 R1200 was fine out of the box. But I do like it better with a few percent more fuel. For some, experimenting with their rides is part of the fun.
 
one thing i have noticed is between 8-9k my 1250 really feels strangled. Well every 1250 i have ridden has done this.

i originally suspected that this was the throttle closing off, i will try data log it and see if i can see if that's the case.
Judging by the above comments i could be the overly rich fuelling.
 
@Moerty, I think your post is spot on. The 1250 is a sweet running smooth engine, and I have no complaints about the way it runs.

My problem is, I can not leave 'Well enough' alone. I keep thinking, 'I have yet to see an strangled engine that does not benefit from a bit more fuel'

I'm a sucker for a challenge, and I have the equipment it takes to check it out. My testing may lead to nowhere, but I just have to know. I guess what I'm suffering from does have a name in Latin, but I'm quite happy with my condition. Besides I fancy electronic projects, and making a single unit handling all 3 O2s would be neat. The parts costs does not come to much, the time consuming part is to analyze the needs for the ECU and write the proper software. I'm partly there as I already have the software that handles the Lambda shifting, the challenge will be to analyze what it takes for to keep the O2 #3 from throwing a fault code.

If all works out, and my personal activity coordinator does not come up with another brilliant idea of an in-house project, this will be my winter project. Probably a total waste of time. But that's the story of my life :hippy

@grant123.
I think that whatever you do to the twin boxer it will always struggle with rising RPMs. With only two cylinders you will get the pumping action in the crankcase, and unless the crankcase is wide open to breath freely, the venting of the case will be an issue with rising RPMs.

The 1250 is probably the best reving BMW boxer produced up to now. But even so, it will not perform as well as V engine or a 180 degree crank boxer with similar heads. But the alternative engines and their design will have other issues. I think we have to accept that we can't have it all, even if it does not stop us from wanting it :beerjug:
 
It's fun to mess about with engines and my capabilities are no-where near as advanced as some on here including knutk and Roger 04 RT. I was observing more that we seem to have an inbuilt dissatisfaction and that things can always be made better, but I guess with the specific example of the 1250, it seems so near as damn-it, why bother? If tinkering is part of the fun of the hobby, that in itself is justification, or rather that there's no justification needed.
I agree with the point on boxer engines and high RPMs...they're not designed for the same smooth and progressive power surge as an inline or vee 4. That's a lot of inertia there with two 600cc pistons firing up and down pressurising the crankcase as revs climb with no means to vent quickly enough as knutk says. If that sort of high rpm riding and power is what's wanted, then the boxer may not be the best bike to deliver that.

We can't have it all but the world would be a less interesting place if we weren't curious, inventive and born tinkerers!

As for every engine being different, yes point taken, but are they all really that far apart from the factory? I'd be surprised if that were the case with modern manufacturing.

Just curiosity but last night I filled up with super-unleaded (99 Ron V Power). I think that there was a slight difference in running, but it's hard to quantify. It'll be interesting to see how or even if mpg is affected.
 
Funny how even an AF-XIED thread is making more and more happy about keeping my pre TFT 2017 Exclusive, seems it has so many good points, and can be physically helped, without casting a spell on it...........:D
 
... That said, the new 1250 is Euro 5 ...

They are Euro4 at the moment - I am sure it will be designed to get through Euro5 when it comes out.

Just a question - if the AFXIED just richens the mixture up in closed loop, is it really worth the money over a BoosterPlug, or even a £35 Accelerator Module that just bungs 5% more fuel?
 
On the topic of the rear (post cat) O2 sensor:

“This method uses an air fuel ratio sensors pre-cat and standard O2 sensor post cat. The AFR sensors test for misfire detection, mixture variation among cylinders and exhaust temperature. The rear sensor checks average mixture, catalyst output temp, and for a few seconds when conditions are right monitors catalyst heath. Direct feedback is not used as it is much to slow to keep the mixture in the range needed.”

From the Bosch Automative Handbook, section on lambda Control: “ ... Here, a slower control loop [after the cat] is superimposed on top of the [first] O2 sensor.”

So it’s really anybody’s guess what strategy BMW took in the R1250 with the rear O2 sensor: simply checking the cat performance or that and fuel control. A real-time data log with the GS-911 could tell a lot.

Is there anyone with the R1250 and a GS-911 who could capture a riding log?
 
They are Euro4 at the moment - I am sure it will be designed to get through Euro5 when it comes out.

Just a question - if the AFXIED just richens the mixture up in closed loop, is it really worth the money over a BoosterPlug, or even a £35 Accelerator Module that just bungs 5% more fuel?

The simple answer is yes. It has been demonstrated by measurement, time and time again, that although the BP and AM lower the air intake temp, they do not add fuel anywhere in the map, open or closed loop.

And through long term Adaptation the AF-XIED adds fuel in open and closed loop (where it’s most needed).
 
... And through long term Adaptation the AF-XIED adds fuel in open and closed loop (where it’s most needed) ...

OK, so it is this bit that a BP doesn't do - that only comes from the O2 sensor trying to correct to the "correct" level. And that eventually feeds through to the short term and long term trims?
 
Interesting so nothing really out there at the moment that would enhance the new 1250................:rob

Improving on perfection...?

Doesn't need anything - so smooth as it is...
 
... Doesn't need anything - so smooth as it is...

But it does still have a flat spot at 5,000rpm whether you notice it or not, probably for emissions or noise - if that was smoothed out it would be as smooth as a very smooth thing:bounce1

r1250gs-v-r1200gs-dyno-wot.ashx
 
Improving on perfection...?

Doesn't need anything - so smooth as it is...

One always needs a little tweak, however so small, the word perfect, is unfortunately absent in my mind, even if it was close to perfect, i bet I would still try and have a fiddle with it, or at least find some who could really with proven knowledge..:p help me achieve my quest for the grail, which I will probably find it in my coffin.
 
They are Euro4 at the moment - I am sure it will be designed to get through Euro5 when it comes out.

Just a question - if the AFXIED just richens the mixture up in closed loop, is it really worth the money over a BoosterPlug, or even a £35 Accelerator Module that just bungs 5% more fuel?

Euro-5 will be implemented 2020. According to my pusher, the 1250 is already Euro-5 compliant.

Short answer about AF-XIED vs Boosterplug: Yes.

Seeing is believing: Check out these voltage graphs from O2 sensor.

Graph of voltage vs AFR:
24852912707_711974e867_z.jpg



Reading from a standard unmodified engine: Throttle blipped between 8 - 12 seconds
48197682941_7f53098bc6_b.jpg



Graph of engine with a fresh installed Boosterplug. No adaptions performed at this early stage. Throttle blipped at 10 - 18 sec.

48197736692_14752468a8_b.jpg


Graph of an engine with AF-XIED at Pos #8.
Red kurve is the O2 sensor reading, while blue line is the signals from AF-XIED in order to reach the O2 shifting.
48197739222_042b42ed27_b.jpg
 
But it does still have a flat spot at 5,000rpm whether you notice it or not, probably for emissions or noise - if that was smoothed out it would be as smooth as a very smooth thing:bounce1

Have you ridden one?

It may show on a rolling road, not that I can feel in real time riding.

It is as smooth as a very smooth thing :D
 
One always needs a little tweak, however so small, the word perfect, is unfortunately absent in my mind, even if it was close to perfect, i bet I would still try and have a fiddle with it, or at least find some who could really with proven knowledge..:p help me achieve my quest for the grail, which I will probably find it in my coffin.

TBH I couldn't feel a flat spot with my Euro 4 bike either - probably a ham-fisted old git...
 


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