Have a 2007 Ultra Classic and have a chance to put on a pair of mufflers off a 2008 Screaming Eagle Ultra Classic. Will I gain anything with this and with no other changes, and will this effect my ECM settings?

Thanks

 

If you change the pipes it could effect your ECM I put a PCIII K&N filter ant V&H Ovals on my 2007 Ultra and it runs and sounds great.

 

pipes is pipes, mufflers is mufflers.

The ECU can cope with those changes just fine. Probably not a performance change worth writing home to mom about. Sound may be some different. Are they catalyst mufflers you want to put on?

 

The SE`s are less restrictive. Therefore you will gain some HP, but might loose some torque.
I would not add less restrictive pipes without ECM calibration changes. The 07`s are very lean to begin with. Buy a SERT, DTT, DFO or other tuner and add the SE-A/C for the best result. JMO.
I have an 07 SG with the DTT/WEGO IID and an 08 Ultra with the SERT. Money well spent IMO.

 

True, a freer-flowing set of mufflers would tend to lean out the mixture if that were the only change made. But the '07 Delphi ECU will keep it right at the same amount of lean it was to start with. That's precisely what the O2 sensors, closed-loop operation, and adaptive fuel capabilities are for. More fuel will be added by the ECU to bring it right back to where it was before in terms of the relationships of the fuel to that of the air in the mix.

Also, the bottom-end torque may well increase less than the mid-range and top-end torque will, but in the end it's very unlikely there will be an actual loss of it.

It will be totally okay to stick those mufflers on the ends of the stock pipes unless they flow more than about 15% better (unlikely) or the flow relationships between the various rev ranges changes too much (unknown).

It would only take about an hour total to swap them out and ride it to make an educated determination of their suitability.

 

That`s a great thought on closed loop operation, but the bike has open loop operation as well..I/E W.O.T. idle and 80% load via MAP inputs.
This will cause open loop operation and could cause internal engine damage due to a lean condition. The new ECM`s have 5 operation modes with closed loop being one. It`s a big risk I would never advise someone to take without knowing the possible down side.

 

While running closed-loop, it'll modulate the fuel to achieve the preset AFR, using the O2 sensor feedback. Whatever modulation that's needed is continually used to update a factor (±15% range) which is used against the VE tables (which are the basis for fueling requirements). The end result is that no matter what mode it's running in, the AFV (adaptive fuel value; the updateable factor) is applied and it should be correct, so long as whatever change was made is linear across the entire VE tables. This is auto-tuning, and it maintains the AFV between running sessions.

Ideally it will cover for changes in fuel (oxygenated, not, etc.), atmospheric conditions (altitude, large-scale weather fronts, etc.), wear and tear on running components (cam profiles, air filter condition, etc.), but it will also work quite well with muffler changes. So long as they're reasonable both in overall flow capabilities and the relationships of those capabilities between the various areas of the VE tables.

If someone with an '07 (and presumably an '08) touring bike asks me can they stick different stock HD mufflers on the ends of their stock pipes my answer is going to primarily be "yes."

 

The term should be is a big variable when it comes to $6500.00 for eng. repairs.

 

Just because you don't understand it doesn't mean it doesn't work and work extremely well.

I'd bet there are literally millions of miles logged so far on '07s (combined) with just mufflers stuck on the stock pipes and no changes made to the stock ECUs. This system flat out works.

I've personally encountered it in action by running just mufflers (which worked perfectly) and then installing a PC and K&N airbox but not reseting the AFV. It ran so rich up top that I questioned whether the canned map was indeed correct. Reseting the AFV, and nothing more, resulted in an extremely well-running system.

 

That`s great...So can you tell me what it is exactly that I don`t understand. While yououtline of operation is correct. Your basing everything on an unknown.
That `s what I don`t understand. You seem to know a lot about it, butyou have an open hole in your theory. I know PCM functions very well. I started my ECM/PCM education on 1979 with GM. This is a Delphi system. I think I know a thing or two about it....Thanks for the vague guess work on AFR/VE based on a 15% change that has no base value established.. 15% of 0(zero) = 0(zero) The narrow band 02 sensors have an operational window of 14.1 to 15.0.
TheAFR is based on VE base settings with a limited adjustment window. The closed loop operationis fixed at 14.7:1 on the 08 PCM`s
It`s better know as guess work when changing anything without proper tuning and verification.Your hoping nothing happens based on previous experience. While for the most part it is true, you should not preach it as gospel. JMOIt`s also my personal opinion that PCIII`s are junk.