D&D Boss Slip-On Mufflers for 2009 FLH Harley
The 2009 FLH Harley Davidson's are already proving to be extremely popular with the HD crowd however there are a few things that you need to be aware of when it comes to the exhaust system. The 2009 system is different than prior years models, even though the bikes look virtually the same.
It's not secret that one of the very first modifications that most Harley Davidson owners make when they buy a new or used Harley Davidson is to upgrade the exhaust system to one that they find more suitable to their tastes. I've never done a study but there aren't many Harley Davidson's on the road with a bone stock exhaust system on it.
We recently had the opportunity to check out the new D&D Boss Slip On Mufflers for the 2009 FLH series of Harley's installed on a Road King and then dyno tested to measure the improvement. If you have a 2009 FLH then you may want to check out this article.
D&D has designed these slip on mufflers exclusively for the 2009 FLH touring models and they include all of the necessary hardware, heat shields and of course, the two muffler bodies. D&D claims to have measured up to a 10 hp improvement in power using these pipes on an FLH, that isn't a ton of power but it's very noticeable and will make your Harley Davidson much more enjoyable to drive.
D&D Slip On Muffers
These D&D Boss Slip On Mufflers are just plain sexy.
You can purchase them in either Slant Cut (left) or Back Cut (right) versions.
They look even better from behind. The stock Harley Davidson mufflers are canted in slightly from the factory. D&D has re-engineered the Boss Slip Ons to be parallel with the rear tire. This makes for a much cleaner and better looking installation if you ask me.
D&D Installation Note: Due to a slight difference in rear mounts the use of additional spacers and bolts may be required. To check your pipes for proper alignment, install pipes without bolting up the rear mounts. Step to the rear of the bike and raise or lower until it's visually aligned. Then determine if the additional spacers are needed. Install spacers and bolts as necessary.
What's even better than the way these Boss Slip On Harley Mufflers look, is how they perform. D&D has engineered a winner here and the D&D Boss Slip On Mufflers combined with a typical AC mod will produce up to 10hp and torque for your FLH. This is enough of a power gain that you should notice a decent increase in the way the bike feels under throttle.
D&D Boss Slip-On Power Gains
This particular test was completed using a Screaming Eagle AC kit but you could just as easily duplicate the results with a K&N kit or even something like an Arlen Ness Big Sucker kit.
Check out the boost in HP and Torque provided by the D&D Boss Slip On Mufflers for your 2009 FLH Harley Davidson. These things ROCK and the best part is that you can install them in about a half an hour! How cool is that?
D&D Boss Slip-On Muffler Bargains
Note: For a limited time a FREE Air Cleaner upgrade may be included in the system you purchase....Read your specific auction to make sure that it is included.
![]() DD BOSS GLIDE SLIP ON SLANT CUT MUFFLER 4 HARLEY 2010 US $269.95
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![]() DD BOSS SLIP ON SLANTCUT MUFFLER 4 HARLEY 09 FLH FLT US $489.95
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![]() DD BOSS GLIDE SLIP ON BACK CUT MUFFLER 4 HARLEY 2010 US $279.95
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![]() DD BOSS SLIP ON BACK CUT MUFFLER 4 HARLEY 2009 FLH FLT US $599.95
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![]() DD BOSS SLIP ON SLANT CUT MUFFLER 4 HARLEY 2009 FLH US $489.00
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![]() DD BOSS SLIP ON MUFFLER EXHAUST HARLEY 2010 TOURING US $249.95
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US $269.95














March 6th, 2009 at 3:49 pm
Can you rate the sound output of these cans? For example, on a scale of 1 to 10 where the stock sound level is a 1 and open drags is a 10.
Thanks
March 6th, 2009 at 8:29 pm
i was wondering if you could help me. i am looking for a set of harley davidson mufflers that look like originals but sound louder. its for a 2008 road king classic
thanks
bob
March 8th, 2009 at 3:39 am
@Matt – Sound is very user specific and what is loud to you may be just right for me but if I had to rate these mufflers I would say 5 to a 6. They have a healthy rumble but they are certainly not an obnoxious muffler if you ask me.
March 8th, 2009 at 3:42 am
@Bob – I don’t know how close you want to come to the stock look but the undercut version of these Bub Mufflers is very close. They look great, sound better and will give your Harley a healthy rumble but maintain a stock appearing exhaust.
As for an exact copy of the stock muffler….I don’t know of one. Hope that helps.