Aluminum Flowmaster?? All Flowmasters I've ever seen are steel, with an aluminized coating. I have two on my race car, and I just put one on my Ranger today. These were all 40 series. Is there another model that's made out of aluminum? -TD

 

No I think they mean Aluminized mufflers not aluminum, there are no such mufflers on flowmaster's site that I have seen.

 

i've noticed the the FM's "break in" too. i've had mine on for about 4 months now and after that second month i could tell it got a little louder and deeper. i dont understand how it can do that, but it did...

 

Aluminized is what I meant sorry for the confusion. Thanks 351M for clarifying.

 

FM or Gibson both rock....Except on anything other than a small block V8 on up....sorry for being harsh, but.....thats just my 2cents.

 

Put Gibson Super Truck exhausts on my new F150 and they are pretty loud when I get on it plus they look great I.M.H.O. Second truck I've had them on and no complaints !!

 

My friend told me about breaking the Flowmasters in, except he called it "racking them out." He told me to drive in first gear till the rpms raise and then let off. He said that this pushes more exhaust through the muffler and it sort of hollows out the center. He does the same thing with his camero except it envolves 80 in 2nd gear. Y'all are right though, flows do get louder over time.