Remapping when adding Akrapovic exhaust tip

[zenwhipper]

I'm in the - I think one should get a new Akra can if they want one - camp. In fact, I am going to procure said unit in January for my '16RT. To heck with the nay sayers.



And... everything I have read, no new mapping is needed.

Cheers.

 

[Omega Man]

I'm in the - I think one should get a new Akra can if they want one - camp. In fact, I am going to procure said unit in January for my '16RT. To heck with the nay sayers.



And... everything I have read, no new mapping is needed.

Cheers.

Good for you. Nice accessory.
OM

 

[alancoles]

I would suggest a high order polynomial curve-fit of the results (both HP and Torque), then making a comparison...

Perhaps I'm wrong but wouldn't doing so actually obscure the results and differences? One typically isn't looking for absolute differences as much as where the differences occur and for how long. I have deleted my software for reading my dyno run data several years ago, but it was able to drill down to specific areas and increase the scale and data-point intervals to provide quite detailed comparisons when I did an overlay of two different runs along with A/F data so that I could identify gains and losses from changes made.

...Those humps and wiggles in the torque curve appear to be the selected transition points between the individual runs in each gear.

That dyno sheet looks like, and should be, the industry standard data from a top-gear dyno pull. With the right dyno and gear one can collect and represent data throughout the gears, but that is very rare to be shown and looks completely different.

The normal way to do a dyno pull is to gently move through the gears at a low engine speed until you get to top gear (or 5th in some cases) and then when in top gear at a fast idle you start recording and peg the throttle right up to or close to the redline. Therefore, the chart shows the curve for a one gear (5th or 6th) run only.

My suspicion regarding the two points where the TQ is virtually identical (4,200-4,400 rpm and 5,000-5,200 rpm) was that perhaps BMW set the computer parameters to be very narrow at those two points for meeting EPA and Euro emissions and/or fuel-economy targets. I've not read what the testing process is since the original EPA stuff was done decades ago, but thought that the two points might dovetail with areas where the testing might have shifting occur. The 4,200-4,400 rpm area for city-loop testing and the 5,000-5,200 rpm area for highway-loop testing. No idea if that is so, just a thought as to what might have produced it.

 

[36654]

Perhaps I'm wrong but wouldn't doing so actually obscure the results and differences? One typically isn't looking for absolute differences as much as where the differences occur and for how long. I have deleted my software for reading my dyno run data several years ago, but it was able to drill down to specific areas and increase the scale and data-point intervals to provide quite detailed comparisons when I did an overlay of two different runs along with A/F data so that I could identify gains and losses from changes made.

That dyno sheet looks like, and should be, the industry standard data from a top-gear dyno pull. With the right dyno and gear one can collect and represent data throughout the gears, but that is very rare to be shown and looks completely different.

The normal way to do a dyno pull is to gently move through the gears at a low engine speed until you get to top gear (or 5th in some cases) and then when in top gear at a fast idle you start recording and peg the throttle right up to or close to the redline. Therefore, the chart shows the curve for a one gear (5th or 6th) run only.

My suspicion regarding the two points where the TQ is virtually identical (4,200-4,400 rpm and 5,000-5,200 rpm) was that perhaps BMW set the computer parameters to be very narrow at those two points for meeting EPA and Euro emissions and/or fuel-economy targets. I've not read what the testing process is since the original EPA stuff was done decades ago, but thought that the two points might dovetail with areas where the testing might have shifting occur. The 4,200-4,400 rpm area for city-loop testing and the 5,000-5,200 rpm area for highway-loop testing. No idea if that is so, just a thought as to what might have produced it.

If the wiggles are real (not pieced segments of discreet gear performance curves) what causes them? Excluding variable valve geometry, it would have to be standing waves or other flow distortion at the inlet or discharge at three frequencies. That seems like a reach to me. I'm guessing the humps at 4500, 5200 and 6600 are artifacts of the test method

 

[desmoderek]

For all you techo geeks, I got a lot of understanding and questions answered by reading some of the info on this link, and the links there-in.
For those interested in why FatDucs and the like do not work, it's all here.
http://www.bikeboy.org/open_closed_loop_efi.html

Good luck!

 

[alancoles]

For all you techo geeks, I got a lot of understanding and questions answered by reading some of the info on this link, and the links there-in.
For those interested in why FatDucs and the like do not work, it's all here.
http://www.bikeboy.org/open_closed_loop_efi.html

Good luck!

Thanks, I'll try to have a look at that next weekend if I get a chance. I noticed the author spoke about the crappy low-speed running of the Ducati St3s (their fueling below 4k is awful to satisfy EPA). Hopefully he'll have a better answer than the virtually non-existent Ducati Performance ECU that is a 4-figure purchase if one could actually be found for sale, my ST3s frustrates me to no end at anything below 1/3rd throttle.

If the wiggles are real (not pieced segments of discreet gear performance curves) what causes them? Excluding variable valve geometry, it would have to be standing waves or other flow distortion at the inlet or discharge at three frequencies. That seems like a reach to me. I'm guessing the humps at 4500, 5200 and 6600 are artifacts of the test method

Those aren't artifacts, just an accurate reflection of what is going on. Here are a few others that will show that it isn't uncommon for bike TQ curves to be more erratic than the typical automobile curve.

Another R1200 curve but with a Remus slip-on:


A group of Superbike TQ curves. Note how erratic the Ducati and KTM are.


There are far more factors at play than valves, intake and exhaust. The fuel injection, ECU, and all other elements are at play as well trying to find that Holy Grail of balance between power, fuel-economy and emissions. Add to that the lightness of a flywheel for any 1.17L twin and pulling 125 HP and 90 lb-ft TQ and the charts show what you get.

If you move to something like my old 1995 3L I-6 M3 engine than the TQ curve gets much cleaner, but that is with a lot of tuning.

 

[roger 04 rt]

Hello,

I was thinking about putting on an akrapovic exhaust tip on my 2014 R1200RT, should the bike be remapped to match the performance of the new and different exhaust?

Thanks

Rudy

The curves that have been shown are a good object lesson in why you don't need to remap for a simple change to the tip of your exhaust. The BMSK in your bike can easily adapt to 15% changes in airflow, which is much more than you can hope for with an exhaust tip change.

Although dyno operators would have you believe that they can fine tune your bike, the data they show is almost always taken at WOT, with an inertial load that is about half the load your bike experiences on the road, and over a mere few seconds of time. Of the three hundred odd fueling points in the fuel map, the dyno displays data from about 6-8 and the amount of time in each cell is less than a second.

Then there's the question of how they remap. If they're altering your BMSK, you better determine that they're as expert as the team of engineers at BMW who tuned your maps on a brake dyne, not an inertial unit, where they could study the VE and AFR at each point, with multiple combustion instruments. If they're adding on something like a Power Commander, you should seriously consider why you would want someone to disconnect your O2 sensors and disable the BMSK's best feature, mixture adaptation.

If you are leaning toward remapping, check out this detailed analysis: http://advrider.com/index.php?threa...-af-xied-for-bmw.749080/page-33#post-23436774, and then make up your mind. If you want more torque in the driving range (<half throttle, <5000 rpm) consider lambda-shifting, which uses the BMSK to add several percent to stock fueling there.

 

[roger 04 rt]

...

I also believe you will be fine without mapping. Even if you added a K&N air filter I do not think you would add enough flow to lean the bike out any more. However if one went full new headers and muffler you might want to have a pull done on the Dyno to see where you are AFR wise.

I guess you would do that with a Power Commander and their Auto Tune with dual O2's ?

...

As long as you keep the O2 sensors connected, and have any kind of reasonable exhaust the very powerful BMSK will keep the fueling as BMW designed it.

Even with auto tune (which isn't very auto and needs to be monitored manually) the BMSK is hobbled by lack of O2 sensor input.

 

[alancoles]

Just got a reply this afternoon on my question to Akrapovic.

Via the Akrapovic website, I sent them the following questions:

New product question from Akrapovic.com
Alan Coles, from Canada, with email xxxxxxxxxxxx.com asked new Product related question on Akrapovic.com with following text:

Product:
• Segment: motorcycle
• Brand: BMW
• Model: R 1200 RT
• Model year: 2014

Question:
1) The Dyno Chart you provide for the Slip-on muffler for my bike show an approximate 3% increase in HP and TQ. Is that with simply installing the Akrapovic muffler, or is tuning involved as well?
2) If tuning is involved would a Dynojet Power Commander V be sufficient or not?
3) If tuning wasn't involved, what might be gained by tuning if anything, and would a Dynojet Power Commander V do what is needed?

Thanking you in advance for your assistance. Regards, Alan Coles

Seeing as I'm located in Canada they had their Canadian Distributor send me the answer that they provided to him.

Hello Alan,

I received a copy of your email from Akrapovic, they asked me to forward their reply.

No re-mapping is needed or was used when developing this exhaust. If needed, we mention this clearly on our web page.

http://www.akrapovic.com/#!/motorcycle/product/road/14625?brandId=44&modelId=373&yearId=2064

There is always a possibility for a slight improvement with re-mapping, although this is really not necessary and would be negligible with a slip-on.


Mitch Rathje
Product Manager
Parts Canada/Drag Specialties
www.partscanada.com

Good info to have regarding the system and that nothing else is required nor of any appreciable help.

Thanks Roger for the link, I'll read it when the time allows, looks interesting.

Agree 100% that the typical US used dyno (an inertia dyno - most DynoJets, etc.) is not of much value for anything other than getting some data. Problem is very few shops in North America would ever consider spending the money on a dyno that is actually usable for tuning because they can spent 25%-50% of that on a typical DynoJet and virtually all of their clientele are oblivious to the severe limitations of the inertia dyno for tuning.

We actually used to do rough tuning on the dyno and then go to the track for a day, data log for several laps, down load the data and burn a new chip on the spot and repeat so that we had good results for the actual usage that simply can't be gained on the typical under 100k dyno.

 

[bdfbeemer]

I got one because the big fat chrome appendage looked awful. A little louder, no appreciable power changes, good or bad. Maintenance is easier also.

 

[pglaves]

With all due regards to Revzilla whic I like, it will still be a totally cold day in Hell when I spend $942 for a diagnostic tool.

Yes I owned a PC V and auto tune. It worked well for me and I enjoyed using it.

REV Zilla has 15% off on it now, 942.00 bucks for the PC V Autotune with 2 O2's and the touch screen.

And add a exhaust can and you get just shy of 2K.

The Screen would be great to see TP and AFR so you can map more efficiently. And to be able to start logging and end it when you like. You can just pull off and make the changes. I had dots on my handle bar to tell my TP % roughly.

I would love to get a pull and see where AFR is on these. I am sure it is lean and from some of the really blued LC headers they must not all run the same.

I would love to run the PC V set up for 942.00 but my frugal side says no..............

 

[roger 04 rt]

...
I would love to get a pull and see where AFR is on these. I am sure it is lean and from some of the really blued LC headers they must not all run the same.

I would love to run the PC V set up for 942.00 but my frugal side says no..............

Your frugal side is right. I've measured many Boxers and AFR below half to two-thirds throttle is lambda=1 (14.7:1). From there to WOT, the mixture is richer, between l=1 and l=0.9 (13-13.2:1), approximately.

 

[Omega Man]

With all due regards to Revzilla whic I like, it will still be a totally cold day in Hell when I spend $942 for a diagnostic tool.

I spent 4K for this-

I think it's pretty neat when someone or myself gets cool new tools- and uses them

OM

 

[roger 04 rt]

I spent 4K for this-

I think it's pretty neat when someone or myself gets cool new tools- and uses them

OM

OM, What is this box? RB

 

[Omega Man]

OM, What is this box? RB

Roger, it's the Solus, vehicle diagnostic tool from Snap-On Tools. It allows connection to the OBD-2 port and allows views of the engine running, checking the sensors, crank sensor association and all you would expect. The next level up with even more features is the Snap-On Modis.
Gary

 

[roger 04 rt]

14.7 is the ideal Stoichiometric Ratio for gasoline. So you are saying you have verified LC RT's run this at 50-66% TP? 13.to 13.2 66% on TP ?

That is some good news and pretty surprising to me. 14.7 is a perfect burn, and 13-13.2 is perfect for power of course all of this as a general rule and exceptions are to be expected I am sure.

Must be great ECU modules in these bikes to keep AFR that good.

In what capacity were you checking these? Are you a tuner? Just curious.

Let me answer your last questions first. I'm a motorcycle rider (with a broad background in electronic systems) that got carried away and spent time over the past 5+ years measuring and studying the BMW ECUs. I started with the Motronic used on the R1150, then moved on to the Motronic used on the R1100 then to the BMSK used on the R1200s and recently on the BMSK used on the "Wetheads". Over the course of that time, I guess I also became a tuner, but only to a degree.

The measurement tools that I've used (and with the help of several other riders too, since I only own an R1150) are the Hexcode GS-911, which can monitor and report dozens of real time ECU parameters, and the Innovate Motorsports LC-1, LC-2 and LM-2, installed in the motorcycles' headers, which reports realtime AFR data.

The BMSK ECUs are indeed very sophisticated ECUs. Most of my time has been spent measuring/studying how they fuel the motorcycle, but some time has been spent analyzing the spark timing too. The reason the BMSK and Motronic spend so much time fueling at lambda=1 is that it is where the catalytic converter works efficiently. The ECUs also apply acceleration enrichment and deceleration lean-off in that range. Above half or so throttle, the ECUs add more fuel and run richer. (This is often not accurately captured on Dynojet Intertial Dyno setups because their Wideband O2 is placed behind the catalytic converter, and due to poor control of initial conditions.)

Here is one of several threads that explains the research, there are some others with more detail: https://forums.bmwmoa.org/showthread.php?56990-2004-R1150RT-Wideband-O2-Sensors. The mid to later part of the thread has more BMSK/R1200 information. Here is a longer fuller version: http://advrider.com/index.php?threa...o2-sensor-project-and-af-xied-for-bmw.749080/.

 

[roger 04 rt]

Roger, it's the Solus, vehicle diagnostic tool from Snap-On Tools. It allows connection to the OBD-2 port and allows views of the engine running, checking the sensors, crank sensor association and all you would expect. The next level up with even more features is the Snap-On Modis.
Gary

Thanks Gary, I'll take a look at it. Does it require an adapter for the R1200 or R1200 LC?

 

[Omega Man]

Thanks Gary, I'll take a look at it. Does it require an adapter for the R1200 or R1200 LC?

Strictly automotive Roger. My mentioning it was just a comment on pricy neat tools.......People thing it's crazy to have my own 55-ton iron worker until they need 100 holes punched
Gary

 

[roger 04 rt]

You can use the AF-XIED from nightrider.com or beemerboneyard to richen the mixture up to about 8%. (Or if you want a science project install dual LC-2s.) All capability of the BMSK is left intact. Easy install. No tuning needed. If you read through this thread you can find a lot of "talk" about it about halfway into the thread: http://advrider.com/index.php?threa...c-exhaust-system.1049137/page-5#post-31030833.

 

[36654]

enriching the fuel by a small amount it improved ride ability.

By ride ability do you mean sensitivity to throttle position?