Could someone explain to me the different types of mufflers. I was told that there are two types. Straight through, and chambered.

I know that the loudmouths are a straight through design where as brands like gmmg and flowmaster are chambered correct? Just wondering how the different types of muffler would effect performance and sound.

 

There are 2 types of bullet mufflers. A straight through design can be hollow (SLP) or filled with fiberglass, commonly referred to as a glasspack. The other type is a chambered bullet like a stainlesswerks or powerstick. These have crushed sections creating chambers inside the pipe which kill sound. You can spot the chambered bullets easily bc of the large crimped sections on the outside of the casing.

 

Wow. Guess I knew less than I thought haha. One thing that I found confusing is they say gmmg is a chambered exhaust but how is that different that say a single or two chambered flowmaster?

 

Well flowmaster is chambered in the fact that when you look into the inlet you can not see out the other end. It has multiple baffles and "chambers" that direct the exhaust gasses out the other end.

Some mufflers are "straight through" meaning when looking in the inlet you can see out the outlet. Usually the pipe directing the exhaust gasses has perferations in it allowing exhaust to go into the muffler casing, which is usually filled with fiberglass similar to a "glasspack" muffler, just of a larger design.

 

Again, I was strictly speaking of bullet type mufflers in my above post to simplify things. Of the glasspack variety, there are perforated and louvered designs. Perforated style basically has a strainer steel pipe going through it, and fiberglass surrounding it will kill sound (slightly). The sound escapes through the holes. It literally flows like a straight pipe with zero restriction. The downside is the overall outside diameter will be slightly larger. For instance, a 3 inch in/out will be 4 inches total in the center area. A prime example of this type is a Dynomax bullet.

A louvered bullet is very similar except the louvers actually protrude into the flow path of the exhaust. Not much but some, so flow is slightly reduced, but you can still clearly see straight through about 80% of the muffler. Fiberglass surrounds and kills sound and through the louvers sound has an easy path to be muffled. Advantages to this are slightly better sound control and they can be slightly smaller in overall size around the center section. Disadvantages are flow but these would still flow close to a straight pipe. Examples of this type would be the Summit brand bullet and the old Thrush Woody woodpecker glasspacks.

A chambered muffler like a GMMG is a whole different animal. It has no sound absorbing material what-so-ever. The whole way it cancels sound is through the chambers. By taking the straight pipe and crimping in down, you have effectively created internal sections or sound rooms. Sound enters, bounces around, some cannot escape, then proceeds to the next crimped section. The GMMG mufflers have 2 main crimps in them I believe which would lead to about 3 total chambers inside, a front, a middle, and a rear. These mufflers make deep aggressive tones with their disadvantage again being even reduced flow when compared to the other bullet styles. Muffler size is limited basically to your exhaust diameter are very close, as these don't have to make room for fiberglass packing. These design can literally be 3 inch in/out with a total size of 3 1/4 inches. Its basically the size of just pipe.

All bullets will have minimal sound control at best, as their main advantage is size and flow. A full case muffler like flowmaster that is chambered is under the same design aspects as the chambered bullet except on a more grand scale and lots more can be done to control sound. Inside the case of a single chamber flowmaster there is one chamber, which is the outside case of the muffler, with only a couple of main baffles diverting sound through it. A two chamber flowmaster has a wall dividing the inside of the muffler into 2 separate smaller internal chambers. A round hole in the wall the size of exhaust pipe lets the sound/exhaust flow into the rear chamber where it is further muffled before it exits the muffler. So a 2 chamber is kinda like 2 single chambers connected together end to end in a way.

Some full case mufflers have a combination of chambers with baffles and fiberglass. Some full case mufflers have perforated tubes in them like the bullets that go through internal chambers. I think just about every version and combination has been tried by someone and is out there ready for you to buy. But how do you choose?

 

Thanks for the write up. Def helped

 

^^ Good explanation of the different types of mufflers are their respective sound qualities! Def clears up some questions for me too! Thanks!!

 

Sticky worthy for sure.