Slip-on Computer Upgrade?

[Gordon S]

Greetings -

FNG (first post) to both the board and the 1200RT world. Just picked up a 2010 1200RT that the dealer had as a demo. However, fifth bike so I'm learning/unlearning/relearning a few things. One thing I am trying to figure out - based upon previous bikes - is whether adding a slip-on exhaust (not a full exhaust with headers) would require either a ECU flash/reprogramming or an added fuel injected ECU (like a Power Commander)?

Thanks,

Gordon

[Paul Mihalka]

First off, welcome to this asylum. Answer to question: a slip-on muffler change would not require any engine control change.

[OlGeezer]

First off, welcome to this asylum. Answer to question: a slip-on muffler change would not require any engine control change.

 

Paul - You're not even going to tell him why, are you?

 

[SuperG]

Could it be because a slip on will only increase noise - not power, therefor no fuel management change needed?

[Boffin]

Could it be because a slip on will only increase noise - not power, therefor no fuel management change needed?

 

That is not the reason, though without header changes it is faitrly accurate - it is because the ECU uses the O2 sensors to correct fueling, so changes to the exhaust are automtically corrected.

 

Andy

[Gordon S]

Thanks,

I figured as much but wasn't sure. Already been in the asylum...I was assigned to the five-sided funny farm for 3 years...

 

[spdyjr]

You guys are a scream. That Paul always seems to have the answer. He should be writing for a motorcycle rag.

 

Hope you get as much out of this forum as I do, Gordon S.

[TestPilot]

That is not the reason, though without header changes it is faitrly accurate - it is because the ECU uses the O2 sensors to correct fueling, so changes to the exhaust are automtically corrected.

Andy

 

It's my understanding that the O2 sensor is only used during steady throttle cruising. During start, warm up, acceleration, deceleration, or wide open throttle (WOT) running the O2 sensor is out of the loop (forgive the pun).

[dirtrider]

Afternoon Gordon

 

As mentioned in the threads above just adding a slip-on exhaust doesn’t force a fueling change. You won’t find a re-flash of the fueling computer available and things like the Power Commander I believe force removal (or blocking) of the stock 02 sensors (there are two on your 1200). At least the Power Commanders I have installed in the past on the 1200 hexhead didn’t use the stock 02 sensors but there was an expensive wide band 02 (installed on one side only) that could be used to tune the system.

 

Most of the runability problems you hear about when adding aftermarket exhaust systems come from a free flowing exhaust system being open enough to allow exhaust reversion issues. That doesn’t always mean lean running either as at some RPM/throttle opening/load ranges it can cause rich or poor operation due to pushing some of the exhaust back into the cylinder during reversion and diluting the fresh fuel/air mixture.

If you are just installing a rear slip-on system the catalytic converter will still remain and that is a very good device to defuse and block the returning standing wave (reversion blocker)

 

I know you didn’t ask this but you might be looking in the future—IF, you ever go with an aftermarket type fuel controller on your 1200 hexhead pay attention to HOW it works in relation to your fueling computer. If the device you choose adds fuel AFTER the stock fuel injection sequence and doesn’t go through the fueling computer (like the Techlusion) that will render your on-board fuel mileage computer useless. Any and all fuel that those things add outside the fueling computer control will not be seen by the fueling computer so will not be measured and figured into the electronic fuel mileage data. That is also the reason why so many people that install Techlusion type devices say they get better fuel mileage after the install. Not a big deal but kind of annoying if you like your on-board fuel mileage computer.

 

[Rinkydink]

Great info Dirtrider,

 

My .02...sure install a slip on, it will be louder, give you no more performance but at all costs don't change out any electronics. YMMV

[Gordon S]

Thanks dirtrider & all. I read a couple of good articles regarding ECU and O2 sensors when I had my Harley, but wasn't sure the same applied here. Interested note about the fueling computer, sounds like an aftermarket fuel controller might not be worth the trouble unless I do a full exhaust & intake upgrade, which isn't going to happen anytime soon. I'll probably put the slip-on on hold since it is more for noise than go, I just need to ride more and quit expecting it to sound like my (former) Harley. Hey, they're both 2-cylinder motorcycles, right?

 

Cheers,

[dirtrider]

 

 

Afternoons Gordon

 

While both the Harley and BMW have 2 cylinders that is about all you can say they have in common when it comes to exhaust note.

 

You will never make it sound like Harley.

 

The (traditional) Harley has a common crank pin with both cylinder rods on one crank pin and V type cylinder configuration that forces a very unique uneven firing pulse. That is what gives the Harley that unique and to some a pleasing exhaust note.

 

On the other hand the BMW boxer is a flat twin boxer with a 360° even firing pulse that gives the BMW a rather flat sounding less than pleasing exhaust note (like even-pulse farting). You can make the BMW louder and with specific tuning and a better cam profile a bit better sounding but will never make it sound as good as a Harley (at least to most people).

 

[Gordon S]

Sorry, my "both 2-cylinder" reply was meant to be a bit tounge-in-cheek since I am aware of the difference between v-twins and boxers. I've had a couple of cars with boxer engines (Subies) and always liked the boxer "rumble" that you get with with an aftermarket exhaust. Not sure you can reproduce that with half the cylinders on a motorcycle.

Cheers,

Gordon