American Custom HD Mufflers

This one will take some reading -- Basically copying my own forum posts. The important thing is that these pipes span two completely different bikes with two completely different exhaust setups -- What worked one way on one bike was completely different on the other. So make sure you’re reading the right part for certain bikes. I’m not even quite sure where the catalytic converter was changed -- My ’08 Street Glide (FLHX) had no cat from what I know. The 2011 Electra Glide Classic (FLHTC) has the cat in the exhaust pipe -- A rather dramatic difference in air flow and sound.

Long story short, I’m looking for “nice, Harley sound” without being too loud or obnoxious. On the ’08, it took the “stock” type baffle setup with a bunch of additional holes drilled into the left baffle. No surprise there. On the ’11, with the catalytic converter in the pipe itself, it took a lot more flow -- The “medium” baffles, still with the additional holes drilled into the left baffle - That made the difference.

And if you’re a ‘newb with tools’ then don’t let any of this scare you -- I have a mechanical IQ of around 15. I shouldn’t be allowed around tools. But these removable baffles are easily drilled out to increase air flow (especially to the left, which seems to be the “big deal” when you’re looking for a “nice balance” in your sound) literally in minutes - And you’re back on the road sitting a little taller in the saddle.
BACKGROUND: If you haven’t already, you might want to visit -- These pipes are stock HD pipes, modified to utilize various removable/replaceable baffles so you can “tune” the exhaust to your liking. You may also want to read over my older blog entry on the also-wonderful in a different way Superflow mufflers.

08 FLHX -- POSTED AUG.04.2010:

First off - Visually stunning. Which, I hate to admit (as I'm not too much into "bling" for the most part), is why I ordered them in the first place. Slash-up with those black anodized inserts - those are the best looking pipes I've ever seen. It's everything I loved about Rineharts, but with the slash that puts them over the top.

Okay - Sound-wise... No baffles = freaking loud. A bit "sloppy" sounding (for lack of a better term) also. Didn't care for it. So, I put in the ("Mid-level") baffles -- Seemed a little tame, but didn't really road-test it (it was raining at the time).

Of course, anyone who knows me knows what I tried next... Right baffle only. Loud with a very generous rumble. Sounds freaking wonderful.

Still, for me, too loud for my neighborhood... I come up the driveway after midnight pretty often. Even on the road (after it stopped pouring), I felt a little "Uh-oh, I probably sound like "that guy" (the guy with the really loud pipes) or something... Hope I don't attract the attention of the local constabulary..." coming over me.

So when I got back in the garage, I let it cool down a bit and installed the left baffle once again. Still haven't given it some miles with both baffles, but it sounds pretty respectable from what I can tell. There's certainly the option of drilling a few more (larger) holes in the left baffle to give it a little more low end.

I'll probably add more once I get a chance to really hear 'em out on the road.

All in all -- Superflow's Max2's (actually again, just the left one) really spoiled me -- $150-ish for great sounding exhaust that isn't too loud? That's off the hook. With these AC's, being over twice as expensive basically for the cool-looking end caps, well, you could certainly spend a lot more. I don't feel any particular "buyer's remorse" or anything though...


Okay - Put both mid-level baffles in and put a few dozen miles on... Different - But I think I actually like it. It's very throaty - low end is strong. Top end is a little 'puffy' under low strain and has a very aggressive and satisfying (for lack of a better term) 'roar' when you jump on it a bit.

Loud (for me), but not really obnoxious. The guys at the dealer liked the sound and loved the styling.



Went ahead and ordered the "quiet" ("stock-type") baffle... That's a long baffle (length of the muffler) in the right side, short (one of the "mid" type) baffle in the left.

Rather nice actually - Definitely more throaty than stock, definitely not too loud. Wound up drilling around 10 1/4" holes in the short baffle to cut a little back-pressure (the difference between "vroom - vroom" and the vroom with a sudden stop and "crack" at the end). Easily my favorite - A nice throaty, deep idle, a decent but not obnoxious growl at higher RPM's, a deer-alerting 'crack' when you give a quick quarter-twist, a subtle, healthy-sounding but 'radio-friendly' rumble at highway speeds.

Sounds like a Harley, but without being "that a**hole down the block with the really loud bike."


I wound up with a fairly random pattern of 1/4" holes (largest metal bit I had, believe it or not). I started with drilling one hole per "flat" part at the nose, then just sort of perforated it with maybe 16-20 more holes here and there.

I absolutely love it now... Just enough throat, just enough growl, just enough roar, just enough volume. It sounds "proud" (for lack of a better term) without being "Hey! Look at me!"

I was sitting a little taller in the saddle today myself...


The "loud" is no baffles. "Medium" is two short baffles (which I ordered originally, but found it to be too loud). "Stock" is a long in the right, short in the left (I ended up ordering the "stock" long baffle by itself, as I already had the pair of short baffles).

I tried the "stock" long right baffle and no left baffle (similar to my old Max 2 Superflows where I used the stock right muffler and Superflow's left muffler, which is basically an empty muffler). Didn't really find it 'right' - but not bad. Still wanted to tame it just a whisker - So, put in the left (short baffle), too quiet - started drilling holes and after 20-ish 1/4" holes, I'm "happy dude."

No adjustments necessary if you're using the stock air cleaner setup.

The "sweet spot" in the back pressure was when a quick twist went from "vroom--ahhhh" to "Brrrrap--pu-pahhh" (for lack of better terminology). "Hard bark / hard release" instead of the Buick-ish "soft" up & down.



Traded my '08 SG on an '11 EGC. Of course, I threw the AC's on after about 20 minutes. Gotta say, with the catalytic converter now in the pipe (from what I'm told), the difference is pretty substantial -- Much quieter & more "mellow" than when on the Street Glide. I'd bet the "mid" baffles would have quite a bit more growl.

That said -- I still like the sound for this bike. It's definitely "smoother and mellower" but the EGC is a "smoother and mellower" bike also. Still blows the stock mufflers away (and still supremely sexy with those "end caps" on).


YET ANOTHER UPDATE: Put in the other "Medium" baffle this evening -- Very happy with the sound on the new EGC (with the cat in the pipe). Would still consider it a little mellow on the Street Glide, but it "fits" this bike very well. Keeping in mind that the left baffle is still drilled out quite a bit, I may even swap them at some point to see if it adds a little sumthin' sumthin'. But I really don't feel the "need" to try it if you know where I'm coming from...

What a difference that converter in the pipe makes though... The ('08) SG was actually a bit louder with the “Stock” style baffle than the EGC is with the "Medium" style baffle.

Buddy's opinion: "It sounds classy - like it should be smoking a nice cigar."


Removed the cat early '11. All bets are off on that one. Changed everything for the better. Runs cooler, went ahead and did the HD/SE air cleaner and the "Stage 1" upgrade -- More power, even better sound, even a bit cooler. Same buddy ('nice cigar' guy) says that it has the "I wanna be
that guy" sound.


In summary -- As mentioned probably repeatedly, I’m not looking to change everything - I just want my Harley to sound sort of like a Harley and not like a typewriter. I don’t want or need excessive volume. And I DO ride through areas that are rather “non-friendly” to loud and modified pipes. To that end - and of course, this is only anecdotal and I wouldn’t suggest that these aren’t “modified” mufflers - At first glance (even after first glance in many cases), these are factory mufflers with factory markings. And with the current setup (“medium” baffles), if someone - anyone - wants to shove a long screwdriver in the end to see if there’s a baffle, they’re going to find a baffle.

See you on the road -- You may not hear me coming from a mile away, but you’ll probably like what you hear.