[JAM1775]

Terrific thread guys....I am at the deciding point to go with 3" straight through mufflers or Lobaks.
...I have 2 1/2" glasspacks in my stock FFR side pipes, they are probably blown after 7K and they are noisy....but guess what, I like the sound and I still can have conversation on a highway. In researching bullet style straight through mufflers I have been advised they "create" turbulence even with louvered tubing. Lobaks , as we know are touted as reducing turbulence and increasing air velocity while scavenging the exhaust . The Lobak manufacturer advised me they also offer a Lobak with a larger center core for those motors turning higher RPMS or HP. The standard Lobak center tubes are 1.25" ( Small IMHO) while the larger tubes offered have a 1.75" center tube. The rep at RPM told me the 1.75" center core, plus the auger openings comes very close to flowing the full 4" of air in the muffler casing. I am still not sure about that claim. I am sure a 3" straight tube flows more than a 2-2.5" tube. I like Red's suggested 3" bullet tube. Thanks for that...Red. Scott...thank you for your comments because you are the first person I recall actually able to report comparable engine response to a before/after Lobak install. With regard to jetting I believe the many components unique to each motor may determine if a muffler change requires more jet. When I make the muffler change, probably to a 3" straight tube model, I will read the plugs or even put the motor on a dyno.