When you reduce back pressure you loose torque. Period.

 

I don't know. I run Rineharts on my 09 and I swear when I switch back to stock mufflers it is both quicker and faster. I agree with the op post. I had a hard time reaching over 100-105 with Rineharts. But with stock muffs, no problem. My engine really seems to run better with stock mufflers.
Gary D.

 

So you are telling me that torque is a factor when running above 100 mph at WOT.

 

I thought you said you already DID replace the stock mufflers?

 

Hi Flow air filter and ECM remap/dyno

 

I did change from stock to slip-ons but never had the chance to blow them out so to speak until yesterday. I noticed a difference in top in speed. I guess the stock pipes are going back on.

 

I have a 2004 RK custom, stock 88 cuber, Screamin Eagle high flow a/c. Just bought a set of SE slip-ons, part # 64910-99, slash down. These are the pipes that say " Not for road use", they sound and look great. My question, I have a V&H Fuel Pak. There are 2 settings listed, one for the SE street perf. Touring mufflers & the other setting is SE Pro One piece muffler. Does anyone know which setting is correct? Also what does one piece mean?.

 

The one piece must mean the 2-1 Propipe, so I'd go with the other setting since says it's for 2 mufflers. If it doesn't work well with that setting it's easy enough to change it to the other.

 

I just chaged my stock muffler on my 2010 Heritage classic. After much research I came upon a new brand called Full Boar. If you go to www.gofullboar.com you can read up on the mufflers. They aren't expensive, but the quality and sound is one of the best I've seen and the manufacturer, Jones Automotive, has a history of making performace exhust systems. I don't know if I lost any top speed but the excelleration and sound sure improved. It sounds like a harley should.