Exhaust changes without changes to the ECU map

[Charlie98]

I stuck a set of Arrow cans on the 796 Monster about a year or so ago, they are great and have really helped the drive-ability both in city riding, and out yonder in the twisties... DB Killers in, DBK's out, either or.  I did buy a second ECU... the idea was to send it off to get it remapped, keeping the original one just in case something didn't work or went haywire; but I've not yet done anything with it.  Aside from disconnecting the exhaust flap (Duc-ee, 696 mid-pipe) I haven't fooled with anything else.  The airbox is still stock, and I run a factory type air filter.

With carb'ed bikes, like my XR650, a corresponding change in the exhaust usually requires adjustments elsewhere in the chain to keep it running right and easy to start, without overheating it, running it too rich, or other issues.  Many years ago I put an open pipe on the XR, and punched a bunch of holes in the airbox... all this required a carb rejet to get it to start and run right.

Given the electronics on the Monster, is it really required to change or adjust the ECU map to better tune the machine, given what I have done?  It starts way better than it did stock, the mileage is about the same, it doesn't really run any hotter... 3 bars, maybe 4 in traffic, the backfire through the airbox is just about gone... and, of course, there is more better throttle and response.  Theoretically, it should be running leaner... leaner than it already was stock, with a corresponding rise of engine run temp, but do the O2 sensors adjust the fuel delivery enough to compensate for the freer-flowing exhaust?

[ducpainter]

Typically, unless you make intake changes, a Monster won't require any fueling changes whether carbed or injected.

[ih574]

I did the same thing with a Monster 695.  Stock pipes are low which I like since it keeps the heat away from my legs.  But those pipes are huge (and heavy).  Bought some fairly cheap Danmoto pipes.  With just those pipes and no other changes, the bike didn't run as smooth as stock between 3K and 5K, with a little stuttering and hesitation at steady throttle and some exhaust popping on deceleration. It still ran well under acceleration and high RPMs.   This bike is used for general slow speed city sporting so I'd really like it to be smooth in that low speed, steady state condition.

I'd read about Lonelec cables, GuzziDiag, IAWReader, IAWWriter, and TunerPro.  So the first thing I did was use GuzziDiag to adjust the CO Trim, which did not require an ECU reflash.  I adjusted CO Trim until I stopped the decel popping.  That took a +20 setting, which is WAY WRONG and the wrong way to fix the problem.  And I don't know if it really fixes the problem or just masked it.  So I decided a reflash may be helpful.  I just didn't want to brick my stock ECU.

So, I bought another M695 stock ECU (ebay) and the Lonelec cables.  Did some more research and experimentation with TunerPro (XDF and BIN files) and looked for replacement M695 maps.  I installed the replacement ECU which then wouldn't start, I think because of an immobilizer mismatch.  So I tested the IAWWriter reflash function on the replacement ECU using the stock BIN file with the immobilizer turned off in TuneECU.  That worked and I could start the bike with the original (black) key.  I then found some information for a Ducati Performance map for the same family of bikes and ECU (5AW HW610).  It was not the whole map, it was just a couple of JPGs of the DP main fuel map compared to the stock fuel map.  Since the stock fuel map was identical to my stock map, I made a new BIN with the fuel settings from the DP map picture.  I also turned off immobilizer and the Lambda sensors.  I uploaded the map, reset the CO trim to stock, and reset the TPS a few times.

It was late night when I tested the bike with the new flash.  It ran beautifully.  Strong pull from low RPM.  No decel popping from any RPM on closed throttle.  Strong roll on acceleration from multiple RPMs.  And best of all, smooth low and mid RPM steady throttle / cruise performance.  I was pleased.  A few weeks later, I tested again during the day with different temperatures and humidity.  The bike continued to run excellently.  Again, I was very pleased.

I know this is not the best way to address this issue.  That would take either multiple dyno runs or using exhaust gas analysis while riding or both.  So until then, I am will keep an eye on the performance, engine temp, exhaust smell, and spark plug color.

r-

Tom C.

[Charlie98]

Interesting you mention the exhaust smell... my 796's exhaust smell has definitely changed, but I put that down more to the lack of a catalyst, with a small nod to what is probably a leaner mix.

I will say the slip-ons completely changed the bike... it will actually tolerate low RPM driving, down to about 3200 RPM, which helps with city driving.  With the stock cans you couldn't take it below 4000 RPM, no sir, it wouldn't have it; couple that with the tall gearing and it was a bit of a chore to drive in traffic.  The cans alone transformed my 796... the gearing change even further.

The freer flowing cans has also helped the heat under the seat... the exhaust still cooks your left leg, but it's not in such a hurry to do so, now.

The closed-throttle pop... yes, with the new cans it has a small amount of pop, but what is noteworthy is the transition.  With the stock cans, it wouldn't pop through the exhaust, it would pop through the INTAKE, and often kill the motor.  It doesn't do that now with the slips.

A remapped ECU would probably help... and I'll probably, eventually, have it done.  I just wanted to make sure I wasn't cooking my motor in the meantime...

[koko64]

Recent experience tuning my Evo1100 has me concerned if the situation has changed between Euro 3 and Euro 4 compliant bikes. I'm concerned about closed loop rpm operation with open pipes for the latest air cooled bikes. My 2013 model bike was ridiculously lean during closed loop operation and it was stock but for the factory DP ECU/Termi pipe kit. The impression I get from some local dyno tuners is that the newer DP ECU kits no longer offer much difference in AFR tune. My concern would be for bikes like the 79X's range. In Australia we get the continental Europe tune, so I would enquire with your local tuners if the situation has changed and when.

Something to consider is I ran back to back testing with and without Termi oem DB killers. Besides the change in noise the bike ran terribly without the inserts with more surging, popping and spitting thru the airbox. It went from bad to obnoxious.  My feeling is that the air cooled bikes are tuned on such a ragged edge that there is less margin with pipes than in the past. I'm at a point nowdays when considering a modification I first look at the tuning options available to assess its viability.

[koko64]

I agree with 574 that some old fashioned tuning method applies. See if the plugs have anything to say.

[Charlie98]

Well... and that's what has me wondering how well the ECU handles a different emission characteristic (i.e. open exhaust.)  In stock trim, the bike really ran like crap... straight up.  A lot of backfiring through the airbox, stalling, hard starts...and, now, none of that with the open exhaust, DBK's in or out.  I'm curious about your dyno runs with the DBK's out... and the poor result, it's almost opposite of what I've encountered.

[koko64]

I tested db inserts on the road for drivability and smoothness. Not only was the exhaust volume obnoxious, so was the lower rpm running. The 1100Evo Termis have a very large inner diameter core compared to many pipes and the parameters of the closed loop tune couldnt handle it. Made me think the tune was for the "omologato" db inserts.
Dyno tune was with billet intermediate inserts from Desmoworld EU.

[koko64]

http://www.ducatimonsterforum.org/index.php?topic=77623.0

[Charlie98]

Ah, I remember that thread.  I will agree... the open pipes are pretty obnoxious, I have to wear earplugs even tooling around in the city.

It must be specific to the size of the 1100 motor vs the 796... I don't have those low-RPM problems at all, even with the DBK's out.

[koko64]

It might explain a lot and why the tuned bigger bore motors are multi valve and water cooled. The 1100 Scrambler appears quite detuned in comparison.

[cencalal]

This process was easy for me on my M695 and has turned out so well that I haven't replaced my ECU.  It's my first fuel injected bike - got it in 2016 - and really wasn't looking for a Monster until I saw this one in black.  Built to a price point and just begging to be set right.  First up - an oil cooler.  I mean, come on.  And slip-ons, after reading that the factory headers were a decent design.  Mine are Microns which were closeouts when they went out of business.  Then a Fat Duc O2 sensor manipulator - no money, big difference.  No more popping, or stumbling when cold.  Cutting or removing the airbox lid I'd tried on other machines, so I went to the largest K&N pods mounted on S4 velocity stacks - really loud but better power and response.  Always reading the spark plugs.  Like night and day, and good enough for me.  I'm going to put on a lightened flywheel.
Thanks again for the help here and best wishes for the new year.
Alan

[koko64]

 Cheers.