Auger style muffler vs Ultraflow/Magnaflow etc..

[whytry]

I have been trying to find out the main benefits of switching from a Flowmaster 40 series to either something like a Lobak (auger style) or just replacing my existing with either a Magnaflow or Ultraflow muffler. Is there a reason the Auger style are not used more? There are several mufflers out there now that are pretty much a straight through design so I don't see the how loud the muffler is being the main reason to choose one over the other, and from what I can tell from internet searching the Lobak's seem to have, in general, have done well with increasing HP.... Is there something I am missing?

My buddy has Lobak's on his 65 Mustang, and it is pretty mild of a motor, but his Lobak's give it a nice deep low rumble at idle and cruise, but WOT it sounds nasty, and by his own admission there is nothing wild about his motor...

[fishtail8]

I've seen some dyno time with pretty hairy small blocks, one of em liked the augers and one of em didn't. A Hilborn injected 355 on methanol with swept forward headers and 3.5" augers worked better than a 355 carbed on methanol with circle track headers and 3" augers. The carbed engine actually picked up 35hp just by changing mufflers. I'm not sure how many different companies are offering auger style mufflers right now, but I think the center core diameters might be the x factor. I suppose if you really wanted to find a difference you could chassis dyno the car before and after changing exhaust... but that might not be feasible.

[camcojb]

We used that "style" of muffler in our open header hydros and flatbottoms when we went to a lake with a muffler restriction. Absolutely killed the upper end power. That is not to say those were the same as what's currently being built, but the style is identical.

Jody