I'm not an expert by no means, but, when you can explain to me what the exhaust has to do with "fuel/air ratio" we can debate this further.

 

If the exhaust is restrictive and you replace it with a very free flowing system then the bike is going to move more air in and out. Thus needing to be tuned or risk running lean and doing damage. If the AC was flowing 100% max air with the stock exhaust on the bike and you replaced it with a free flowing system then the air flow would be the same and not need to be tuned. In theory this would not change anything. Personally the bikes already run lean from the factory so I could see the benefit of tuning a stock bike for comfort and probably a very small gain.

 

Here ya go

 

Webo, i agree with everything you said. Lets not forget to mention, if your exhaust was restricted and the A/C was sucking 100% the engine wouldn't run very good. You need to expel what you take in.

 

We know that with Stock exhaust and Stock A/C unit we are not at 100% air intake, but we also know that the Stock A/C is very limited. So as Webo shared if you allow the exhaust to flow easier it will provide more flow which only equates to more air, hence the stock A/C unit cannot provide the required amount. So now we have two restrictions, not enough air nor enough fuel because the ECM is still programmed to only allow the factory settings for each.
If you are really in question of this, ask another forum. I too like to learn as I go. I have been working on cars and bikes a very long time and whenever you alter one, one must alter the other as well.. Intake/Fuel/Exhaust all go hand in hand.

And tdivy32, I want to bring this back on track to your original post...... it is a matter of what you like.. I hope this side bar has not taken you down a path that confuses the question

 

Love our Dresser Duals with Monster Rounds. Took the fiberglass baffling out of the mufflers and now they are perfect, not too loud.

 

I agree with V-MAN. MGS is quality and sounds great. You can't beat their pricing. I went with their slip ons but now I want to finish the project and go true dual. Good winter project.

 

Excerpt from Nightrider Technical notes:

Do I need to remap my ECM when installing exhaust and air cleaner upgrades to my 07 and later Harley?

NO, you do not have to do anything. You can put the mufflers/air cleaner upgrades and ride the bike without having to worry about the engine. The simple truth is that the ‘07 and later HD's will run just fine with exhaust/air cleaner upgrades and you do not have to do anything to the ECM at all. Closed loop EFI operation uses feedback from the O2 sensor to maintain a constant AFR,even if changes are made to the exhaust and air cleaner.

There is more independent proof that you do not need to remap the HD EFI when installing mufflers. The March 2009 (page 66) CycleWorld dyno-tested a set of slip-on mufflers on an '09 FLH, getting 5% more HP and 9% more torque on a "bone-stock, including EFI mapping" bike. Cycle World is not known as a big Harley cheerleader, so it would be a reasonable assumption that they are not going to do any special favors for MOCO. The CycleWorld information is right in line with what HD published in the Fall/2006 Enthusiast Magazine, showing a 3% HP increase and 7% torque increase, with slightly more restrictive mufflers and an air cleaner kit. American Iron Magazine has also published similar articles about "no remap" upgrades involving exhaust/air cleaner changes. How much information has to be presented to Harley riders that remapping of the ECM is not required for exhaust/air cleaner upgrades for closed loop bikes? When it can be shown that much of the"gain" in power, for bikes remapped with expensive tuning software and piggyback controllers, would have occurred without spending $400-$1000, riders need to start thinking about what they are really trying to accomplish on their bikes, rather than blindly following the "you must remap just to add exhaust/air cleaner" advice, that has been discredited. American Iron Magazine routinely presents exhaust/air cleaner upgrades on ’07 and later bikes, without doing any ECM remap's. As one of the premier HD magazines, you must assume that their technical staff has some knowledge about how the Delphi closed loop ECM works.

anyway, just sayin'...

 

I'd rather optimize 2-3mpg and 5hp on a bike with tuning than leaving it on the table. I want it running great, not just good enough.

 

You're tilting at windmills, Deuuuce. One will never achieve maximum horsepower AND maximum fuel economy. You'll have to settle for one or the other.

Based upon the chart below, I think most folks would be quite happy landing anywhere in the 13-14:1 range.