Let’s talk chambered mufflers

[FlatbedHemi]

from the dawn of time there has been an argument as to wether or not chambered mufflers actually give any performance or restrict flow. Well, I am gonna stir that pot a bit.

Wondering how the flow actually is on a chambered muffler. Surely they have to be better than a factory muffler, but on a stock pickup (especially a 2500) can you really expect any gains from a muffler swap, really? I’m sure the consensus is no. So are the chambered mufflers really any better or worse than a free flow muffler for a vehicle that is 9,000 lbs and spends most of its life at highway cruising speeds?

Just wondering. What say you?

 

[DG208]

Take a look at my last post regarding Borla Touring vs the Flowmaster 44. My truck has a pulsar installed and since moving to the Flowmaster I have noticed a definite reduction in performance with a chambered muffler. No numbers to back it up but definitely not my imagination either.

 

[Matts175]

I cut my factory "hot water tank" off and added a 14" Magnaflow and then later on deleted the resonator. It sounds awesome, but, honestly, it's not any faster at all. IDK, maybe it picked up 5 hp or something. But that's like, what, a 2% gain? The reason I think is that if you're not going to upgrade what's up ahead (the log manifolds and that pinched up factory Y-Pipe) then it's not really going to matter.

Think of it like this. Let's say you have a 5/8" 50 foot long garden hose. Then you get an adapter and attach a 10 foot long 2" diameter fire hose to the end of it. Are you going to get more water out of the end of it? Nope.

 

[DG208]

My situation may be s little different since I added the catback and the pulsar at the same time and then added the flowmaster 44 in place of the Touring muffler afterward. So I can’t really compare it to stock but a very noticeable downgrade in performance when compared to the Borla. Especially in performance mode with Mds on or off. Size of the pipes not so much the issue as is the back pressure caused by the chambered muffler vs the more straight through path of the borla

 

[johnny_munyak]

I hear ya. Recently removed the crushed Y pipe and replaced with 2.5" pipes from cats back into an X pipe and then into a set of bottle mufflers (single chamber, non-glasspack) with stock tailpipes/tips with no resonators. This replaced my si/do Flowmaster 40 series muffler I had in it previously.

The difference was quite noticeable in sound tone...more refined, clean and NO drone. I was concerned about losing some low end grunt, but have not noticed any.....what I did notice was an improvement in fuel mileage or around 1-2 MPG. HP wise...hard to tell.....but it definitely feels a little stronger.

All said and done....it was a worthwhile upgrade.

 

[abouttobeglue]

Gibson mwa or black widow, straight through flow and a bit of chambered sound. Have your cake and eat someone else's cake too.

 

[DG208]

I hear ya. Recently removed the crushed Y pipe and replaced with 2.5" pipes from cats back into an X pipe and then into a set of bottle mufflers (single chamber, non-glasspack) with stock tailpipes/tips with no resonators. This replaced my si/do Flowmaster 40 series muffler I had in it previously.

The difference was quite noticeable in sound tone...more refined, clean and NO drone. I was concerned about losing some low end grunt, but have not noticed any.....what I did notice was an improvement in fuel mileage or around 1-2 MPG. HP wise...hard to tell.....but it definitely feels a little stronger.

All said and done....it was a worthwhile upgrade.

Forgot to mention that as well. Even in eco mode on my pulsar I seem to be getting slightly worse gas mileage with the Flowmaster than I got in performance mode with the Borla

 

[johnny_munyak]

I didn't notice ANY gains/losses (measurable anyways) when I just did the muffler change from stock to the Flowmaster. Liked the sound though....like it even more now with the true duals and the fuel mileage increase was a nice plus...

 

[ram1500rsm]

Do a little google. Chambered mufflers can rob peformance, And Chokemasters have gained that name for that very same reason

 

[FlatbedHemi]

I cut my factory "hot water tank" off and added a 14" Magnaflow and then later on deleted the resonator. It sounds awesome, but, honestly, it's not any faster at all. IDK, maybe it picked up 5 hp or something. But that's like, what, a 2% gain? The reason I think is that if you're not going to upgrade what's up ahead (the log manifolds and that pinched up factory Y-Pipe) then it's not really going to matter.

Think of it like this. Let's say you have a 5/8" 50 foot long garden hose. Then you get an adapter and attach a 10 foot long 2" diameter fire hose to the end of it. Are you going to get more water out of the end of it? Nope.

Oh, I understand the concept there, and I studied long and hard on this topic before. When I bought my truck (2015 with 36K on the clock) the the previous owner cut the factory Y-pipe off and went with a set of true dual 2 1/2" pipes to a short D/D flowmaster (that a realized after removing it was actually installed backwards) with dual tailpipes. It was way too loud and raspy for me, so I took it out and went back to a stock style system. I used a Flowmaster Y-pipe into a single 3.5" pipe run to a Magnaflow 22" muffler and exited through a Flowmaster universal tailpipe. It droned terribly so I went to a stock-like muffler and found a factory tailpipe and resonator. The muffler I used was a Walker replacement HD truck muffler (like as in class B delivery truck). It is similar structure to the stock muffler, and has a stock sound when cruising. Im not sure if it has any agressive sound under acceleration but I havent noticed it. Its only got 2 internal expansion chambers rather than the 3 of the stock muffler, didnt have the flapper inside, and did not choke down to the 3" pipe internally like the stock muffler did. I dont know if it did anything for performance, but Im pretty sure it didnt hurt anything. The sound is quiet with a slight rumble at idle thats about as aggressive as a stock hemi challenger or charger. I like it, but I do wonder from time to time if I could go back to a performance muffler. I have been looking at the Flowmaster 50 series big block muffler, and wonder what I could expect from a muffler swap. I know I wont expect much, if any gains. I feel like my "big truck" muffler flows pretty good, but I didnt want to put a choker on it just trying to get more sound (that Im not even sure Im gonna like).

Probably wont do anything with it, but I do think about it often.