I have an 06 dyna superglide custom. I have a SERT. I put in the screaming eagle air filter and had run Rush slip ons 2.0 baffle. I adjusted via the SERT basically modifing the suggested stage one down load. to richen it up. After many attempts on the SERT it was running fine ie. noback fire popping etc. I then changed back to the stock mufflers and it runs so much better and faster 0-70 mph. It pulls likea raped ape. SO are all these aftermarket pipes just tuned up for sound or just high rpm power where none of us ride consistently?

 

I think its a mixed bag my friend. I swithed from stock to SE IIs mufflers that was more noise similar power, then I went to a Thunderheader, that got me some big torque and added noise.

I installed a Hi comp 95 in kit and stuck with the Thunderheader, and it was awsome.
then I switched to A Rinehart 2 to 1 with a 1 7/8 primary header, lost a lot of back presure and bike ran like crap. I instaled some Sampson torque cones and retuned the Mikuni and got most of the power back.

Summary: stock engine mostly more noise, good pipe= better torque. Hot rod motor + good pipes= bigger power + lots of noise!
Any engine + wrong pipes or bad tunning= lots of noise and no power!

 

on my '93 ultra I had the se breather, ev-27 cam, and se mufflers. my feeling was that the low end was weak with the se mufflers, but the top end was real good. just the oposite with the stock mufflers.good low end and mid range, but was chocked at the top end. whenever I switched them it seemed like I had a new bike, as far as the sound went.

 

I agree with the feel of the stock pipes. When I change back to stock mufflers it really seems like the bike has a lot more torque.
Gary D.

 

I just did this yesterday. I was running a K & N air filter with PC III and Rinehart2-1 on my 07 Steet Bob. After spending over $800.00 for a so called performance boost my bike was a dog up to mid range. Very disappointed with the low end. I took off the K & N and put back on the stock a/f and stock exhaust. Loaded a canned map for stock system and got my low end back. I'm now selling the Rineharts.I've heard the Fat Cat is a better performer, but for now I'm leaving it stock with the PC.

 

I am initially pleased with the results after having removing my performance mufflers (Sampson Ovals)and puttingstock mufflers on my 2001 FLHRCI equipped with V&H Dresser duals, Screaming Eagle air cleaner, six speedand SERT. I'll know more afterriding through theColorado mountains next weekbut here in the flat lands of Kansas I notice no lossof any thingexcept noise - which aftera few hours of riding wasbecoming a bit tiresome. The wife says that the Roadking "no longer sounds like a Harley."

Maybe I'm finally getting old and next will be wanting to remove the V&H Big Radius exhausts on my FXSTC.

 

Stock mufflers pull hard off the bottom because of the increased back pressure, they wont pull hard in the upper ranges though where back pressure hurt perf..