There's absolutely nothing wrong with Xieds. They do, more or less, what they say on the can. Trouple is - that aint a lot.

EFI Harleys have closed loop (low throttle & cruising) and open loop (accelerating and pouring it on). Stock engines are lean in closed loop to meet EPA standards. Xieds alter the closed loop bias to add some more fuel in closed loop operation.

Now that's great. Trouble is, that's not doing diddly-squat for open loop i.e. where everyone wants power.

If all you want is to be able to make some noise and have the engine run a bit cooler whilst doing it, then Xieds are great. If along the way you'd like to unleash what you engine can really do then Xieds aint the answer. Something that sticks some fuel in is.

 

Note the following info from Nightriders web site:

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 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.

The amount of information about what has to be done '07 and later Harley when installing exhaust/air cleaner upgrades has been the subject of FUD (Fear, Uncertainty and Doubt). Riders, Dealerships, Parts Suppliers and Aftermarket Shops have presented old-wives tales, bad technical information, mis-information and in some cases, just plain flat lied about the capabilities of the Delphi closed loop ECMs on these bikes.

Most people hold on to their old ideas about what was required for the early EFI ECM's. Shops and Dealerships never bothered to learn new the new technology. Marketing information did nothing to dispel the differences between the old and new bikes. Sales staff did not know the difference or mis-represented what was required on the new bikes.

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 CW information is right in line with what HD published in the Fall 2006 Enthusiast Magazine showing a 3% HP and 7% torque increase with slightly more restrictive mufflers and 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/ac" advice that has been discredited.

American Iron Magazine routinely presents exhaust/air cleaner upgrades on 2007>later bikes without doing any ECM remap's. As one of the premier H-D magazines, you must assume their technical staff has some knowledge about how the Delphi closed loop ECM works. So you can be fairly sure that when AIM publishes a dyno sheet with improved power and the bike did not have an ECM remap, that the information is accurate.

 

I normally don't get involved in the tuning forums because most folks will defend their tuning $$ to the death, but your explanation is so correct and so complete I had to chime in. If you read the TTS Mastertune instructions carefully, even they admit there is no need to retune. The only advantage is if you are constantly in open loop mode, and I hate to say it but a Harley engine won't last too long doing that, tuned for peak performance or not.

 

May edition of American Iron has an article where they install D&D Boss Cats on an 2009 Road Glide along with a Zippers Maxflow air cleaner. No download or tuner.

 

Maybe I'm reading nightrider's information wrong, but aren't the air cleaners and exhaust options being discussed in this thread LESS restrictive (i.e., more free flowing)?

And another point... while this is only anecdotal, two buddies put slip-ons and SE air cleaners on their bikes with no download or tuner of any kind, and both of their bikes were coughing, backfiring and shooting flames from the exhaust......... until they got the download.

So when someone says to me that you can change intake/exhaust ***** nilly with out worrying... I tend to roll my eyes a bit. I'm no expert, but I know what I saw, and it didn't look healthy.

 

Only if you change the head pipe. Mufflers only, no tune. That being said, if you are just changing mufflers in the hopes of more sound, you will be disappointed. Unless you remove the cat, you won't gain much of anything. Your best bet is the whole package-intake,exhaust,tune. Even doing it yourself will run at least $600. It is money well spent. BTW, I recommend a tune with any change as bikes run too lean,hot from factory. Finally, do not waste your money on HD's stage 1 download.

 

What years were their bikes?