I have a set of rolling thunder (I think) mufflers with 1 3/4 baffles, they sound ok but dont have as deep as sound as I would like, I have an exhaust bender & pipe at the shop & figured I would try building my own baffles.

I started with 2 1/4 pipe & drilled a million holes in them wrapped them in fiberglass & bumped the ends up to fit snug in the muffler housing, they sound deep & have a great tone to them, exactly what I was looking for but when I ride it the resonance is unbearable, it sounds like I am in a 55 gallon drum & someone is beating it with a sack of potatoes, anybody have any suggestions on how to keep the deep tone but loose the resonance?

If any of you have ever had a big inch engine in a car that had dual exhaust dump in front of the rear axle you know what I am talking about, funny thing is my wife says it sounds great, no resonance for her, go figure.

 

How about perforating the baffle, kinda like a reverse cheese grater, so it's not smooth on the inside. Might break up the air flow resonance. That's what the interior of my baffles look like.

 

BRYAN TTM has a Sawzall.

 

actually BH has the answer...dimple them holes with a BFH where it scoops exhaust into the fiberglass packin