BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

On my last bike (Yamaha TDM 900) I removed the air box and replaced it with a pair of conical K&N air filters. I also had replaced the mufflers with more free flowing ones. In order to have the bike run properly a had to have a power commander and dyno run.

Can I do the same air box surgery on my R1200R? I already have the Acra mufflers.

I cannot find a Power Commander for the R1200R. Is there really no Power Commander for my bike?

Oh, why do I want to do this you might ask? And my answer is that I'm allergic to plasic and want to have my bikes as clean looking as I possibly can. And I also like to change and alter things eventhough they work just perfectly...

TIA

/Nils

"And I also like to change and alter things eventhough they work just perfectly..."

Marvelous! Let us know how this works out for you.
Mark

My Experience with air boxes. When the Honda Valkyries came out there were all kinds of theories about how to 'increase air flow' by opening (hacking) up the air box. The results were usually a 10 to 20 percent decrease in horsepower (on the dyno). A lot of guys spent big bucks buying new air boxes.

Seems to me that BMW has spent a lot of time and money designing a motor that flows air in a very effective manner. Maybe it could be improved (with a LOT of time and money), but I imagine that the results (in real horsepower) would be minuscule and only of interest to an all out racer looking to cut .001 seconds off his/her lap time.

naturally IMHO,etc,etc

mogu83 wrote: Seems to me that BMW has spent a lot of time and money designing a motor that flows air in a very effective manner. Maybe it could be improved (with a LOT of time and money), put I imagine that the results (in real horsepower) would be minuscule and only of interest to an all out racer looking to cut .001 seconds off his/her lap time.

naturally IMHO,etc,etc

Thanks for the reply!

I don't know how similar the TDM-engines and the BMWs boxers are, but they are both twins... But I was told that the TDM would lose a lot of torque at lower revs if I removed the air box, but I didn't experience that. Maybe the power commander (PC) cured most of the loss.

I tested to run the TDM after the surgery without a new mapping in the PC, and there were a lot of blue smoke coming from the exhaust the few seconds I let it run... I didn't have a map that was exactly as my bike was configured. there were none without an air box, so I tested one with the same mufflers and other air filter. I later had the bike dynoed, but they said that the mapping was pretty accurate.

Is it possible to tweak the air/fuel mixture on the R1200R?

/Nils

Power Commander 111 here: http://www.powercommander.com/powercomm ... 14&yr=2008

mickyt wrote:Power Commander 111 here: http://www.powercommander.com/powercomm ... 14&yr=2008

Thanks! It does not seem to be sold in Europe yet and there are no maps for the European bikes yet. I hope that it will come over here before the season is over...

My local dealer told me that especially the BMW's are in great need of a PC, since they are difficult to get stable in low revs. Is this just sales talk or is there any truth behind it?

/Nils

kallakaki wrote:My local dealer told me that especially the BMW's are in great need of a PC, since they are difficult to get stable in low revs. Is this just sales talk or is there any truth behind it?

/Nils

I have no idea what he means about "stable in low revs" - the older 2 plug oilheads had fueling problems causing a "surge" effect.. once BMW went to the 4 plug (2-plug heads) setup surge went away.

I had a couple of K&N-filters laying around so I disconnected the rubber pipes between the intakes and the air box and attached the filters directly to the intakes and went for a short ride. I could not detect any big difference and there were no popping or blue smoke or any other anomalies. Perhaps there was a slight hesitation when accelerating with moderate wrist-twists. I actually think that it was smoother than before. And of course the growling sound from the intake is now free to listen to...

I think that I'll perform the air-box-removal surgery when I get the available time.

/Nils

I wonder if any of you know if the removing the air-box and replacing it with two separate K&N-filters might increase the air/fuel-ratio too much for the control unit to handle? I certainly don't want to have the bike run too lean and overheat it!

I thought that I might check on the spark plugs to see if they are white, but I've never dismantled a boxer engine before and I wonder where I can find a description on how to remove the spark plugs? Do I need any special tools?

Thanks!

/Nils

I would imagine that replacing the existing system with a couple of pod type K&Ns would result in a drastic reduction in air flow and result in a mixture so rich it would eventually foul the plugs. I do hope your bike is still under warranty and that you have a friendly dealer, because the mods your contemplating could easily result in a cooked motor.
I don't think this is the place to get into modifying engines, but suffice it to say that with an engine as sophisticated as ours (109 HP out of 1200cc) any extra horsepower would not come easily or cheaply.

Good Luck

Thanks for the reply. The original manifolds are now back in place until I get the Power Commander and have the bike dynoed. I hope that the PC can make sure the air/fuel-mixture is correct...

I thought that the K&N-filters like this one were more free-flowing than the air-box configuration?


Btw. I'm not looking for more power, I just want to have a clean looking bike without as much plastic parts as I possibly can remove...

The factory airboxes always have many hours of rocket science engineering built into them for a broad range of torque, max peak power and minimal noise. EVERYTHING has a purpose. The large amplitude intake pulses and even sound waves are utilized in the dynamic tuning to INCREASE airflow for the entire RPM range, over just an open tube. The size and diameter of the short visible inlet tubes, different in the R1150 model lines, changes the power curve when swapped between models.

Clamp on pod filters have so many disadvantages that they do not belong on a street bike. I don't think they belong on ANY bike because of the quick throttle power stumbles and serious dips in an engine's power curve they cause. The Boxer's low frequency, high amplitude symmetrical intake noise is so powerful at full throttle it'll make your eardrums itch without earplugs. The pods are vulnerable to sun fading and endcap cracking, water absorption and foreign object contact damage. They go to hell fast and don't last. Even the K&N's.

In my shop I dyno'd over 1,200 Motorcycles in 10 years. The dyno room noise from bikes with pod filters is so powerful that even earplugs + industrial headband ear cups weren't enough protection. If you want to trade everything else for MAYBE 2 HP near redline, those too porous K&N filters (don't get me started!) are for you. I wish I had a dime for every internet brianiac procedure that cut up an airbox and expected improvements only to find out there were more power losses than gains. Sometimes duct tape can fix all the inch diameter holes they drilled. Sometimes not. No, a Power Commander cannot fix all those dips because it's about dynamic turbulence degrading the airflow and cylinder filling, not the mixture.

I did cut off the very end of my snorkel at a 30 degree angle because I couldn't stand the look of a 1957 Chevy's stock air cleaner. I believe because the change was so minor is why it still Dyno'd at 80.3 HP (slightly higher than stock).

Aren't those guys concerned with looks over function on Harley's?

.

Thank you for the thorough answer!

I understand that the air box has a number of purposes, as you mentioned. But it is not making the bike look better! (In my eyes anyway...)

My plan is to remove the box and compensate as much as possible by adding K&N clamp on pod filters with filter wraps, a power commander and have it dynoed.

As I mentioned before I'm not after more power and I will not lose any sleep over minor dips in the power curve.

I'm just a curious person wanting to try different things to see if I can improve the looks (again in my eyes...) without doing any damage to the engine.

CycleRob wrote: In my shop I dyno'd over 1,200 Motorcycles in 10 years. The dyno room noise from bikes with pod filters is so powerful that even earplugs + industrial headband ear cups weren't enough protection. If you want to trade everything else for MAYBE 2 HP near redline, those too porous K&N filters (don't get me started!) are for you. I wish I had a dime for every internet brianiac procedure that cut up an airbox and expected improvements only to find out there were more power losses than gains. Sometimes duct tape can fix all the inch diameter holes they drilled. Sometimes not. No, a Power Commander cannot fix all those dips because it's about dynamic turbulence degrading the airflow and cylinder filling, not the mixture.
.

Nice try CycleRob, but some people have to learn for themselves. Many times experience is the result of an ill-advised action.

Et quicumque non receperit vos neque audierit sermones vestros exeuntes foras de domo vel de civitate excutite pulverem de pedibus vestris

mogu83 wrote:Nice try CycleRob, but some people have to learn for themselves. Many times experience is the result of an ill-advised action.

I'll have to admit that my experiences with engines are quite limited, but I performed the same surgery on my last bike (Yamaha TDM 900) and I rode it for about 30,000 kms/three years without problems.

But as you point out mogu83; it is indeed a good advice to advice other people NOT to do this until I (or someone else) have tested it properly on the R1200R.

Yesterday I dynoed the bike and they made a lot of adjustments to get the air-fuel mixture-line nice and flat in order to get a smoth and rideable bike. Earlier (after just replacing the original muffler to an Akra) my bike popped quite a lot when dropping the revs. This seemed to disappear after the dyno adjustments.

Anyhows, here is the graph showing the bike with air box removed, akra slip on and separate K&N filters attached direcly to the intake, before (in blue) and after (in red) the dyno adjustments.


I know that a lot of you have discuraged me from doing this , but I felt that I had to try it out for myself and as I mentioned earlier I'm not out looking for more power. Instead am interested in removing as much plastics (and un-necessary things ) from the bike as I possibly can and possibly make it more smoth and rideable without "hurting" my beloved ride.

Has anybody dynoed an original R1200R?
Comments on the dyno chart?

Interesting charts (and I've used the same dyno quite a few times..) The mixture is richer - you can see it on the mixture plot and on the HP chart (less small wiggles in it.) The power increase rear-wheel is pretty impressive. I'm used to thinking in HP and ft/lbs so I can't comment on the absolute numbers..

I assume these runs were made back to back? Just change the components and run it? Environmental variable can make a considerable difference (I've seen up to 10%) if done on different days (humidity and temps are the important ones. The dynojet supposedly compensates, but it isn't all that good at it and most operators sort of forget or don't bother doing it.)

EDIT: I see from the run notes at the bottom they appear to be taken 1 hour apart, and the humidity, altitude are the same and the temp barely varied.. as I said - interesting plots. Impressive.

Be interesting to make one change at a time and do a run with it (ie - mixture alone, exhaust alone, intake alone - each with a run) to see what is the biggest contributor.

Have to get mine to the dyno sometime and run it.

In looking at it again.. I may have misunderstood what it represents.

In reading your note - is this two plots of the same bike hardware (modified intake, exhaust) with just a change to the mixture making the difference in the two plots?

If so - what we really need is a plot of the same bike in stock factory configuration as a baseline plot..

Best,

deilenberger wrote:In looking at it again.. I may have misunderstood what it represents.

In reading your note - is this two plots of the same bike hardware (modified intake, exhaust) with just a change to the mixture making the difference in the two plots?

If so - what we really need is a plot of the same bike in stock factory configuration as a baseline plot..

Best,

Yes, you're correct. It's the same bike hardware. With original map and adjusted map.

I found a chart for a R1200S(?) on Akra's site: http://www.akrapovic.com/motorcycle-exh ... 54a94e230/'
Is it a typo on Akra's site? Why should they show a chart for the R12S on this page?

The torque looks somewhat similar to mine up to 4500 rpm. After that my curve looks more even. I seem to have lost some torque on higher revs. Are the K&N filters too restrictive?

I think that I'd rather have a torque curve that is flat (horizontal) than have a curve that varies hugely over the different revs.

We unfortunately have full winter for at least two more months so I have to wait and see if this difference is noticible.

If you would like to convert from Nm to lb/ft and from Horsepower to PS (Metric HP) you can use this converter:
http://www.mr2ownersclub.com/converter.htm

I think if the two curves were plotted on the same scales they would look quite similar (if different in torque/hp - which I attribute to a difference in the dyno's used.) It has been my experience, the only way to really tell if things have improved is to do back to back plots, changing one variable at a time, then finally combining all the changes and plotting the results vs a totally stock bike run taken the same day. If you don't do it that way - methodically - too many outside variable creep into the data gathered. I've seen big differences with just a different person doing the run (on the bike..)

But - interesting plots, thanks for posting them.