magnaflow XL vs straight through

[b5visser]

Hey guys,

I have a magaflow XL 3-chambered SI (3") DO (2.5") muffler on right now. (PN 13288). I am wondering if there would be any difference in performance switching to a staright through SIDO muffler of comparable size. (PN 12268). My mileage with this muffler really hasnt changed at all...if anything its gone down thanks to my heavy foot...

I am also wondering if the straight through muffler would be quieter than my existing one. Im planning on doing some exhaust renovations here in the next few weeks and want to make the correct choice.

motor: 5.3

Thanks

Brandon

[tomdunn]

I would think that the straight through muffler has better performance than a chambered one.

[b5visser]

yeah thats what i was thinking too...you think it would be worth purchasing a new muffler thats has the signature magnaflow straight through design??

this is totally my mistake- im getting a tune from justin here coming up and i want it to perform at its peak!

[b5visser]

i also hate drone.

anybody with expirience??

[Budlight Chevy]

From what I have experienced the more chambers the more drone. When I had a flowmaster 40 series dumped it droned bad. I mean until the point it would drive you out of the truck. But when I went to they single chamber dumped it totally went away. I think a straight through muffler would be more poppy and crakly i dont like this but some people do my single chamber is a hollow loud deep sound. It also can wake some neighbors up when under WOT

[b5visser]

i think thats what most people are after....give me a loud exhaust under WOT and something thats quiet when im cruising. the worst speed for drone is between 50-60 when the tach is around 1500 rpm...

im completely redoing my setup this weekend- rigging up some side exits before the rear tire- I am expecting some drone. Well just have to see how bad it is and how long i can take it before swapping somehting else in.

[tex2500]

1500-2000RPM seems to be the sweet spot in terms of really bad drone on chambered mufflers, dumping the exhaust doesnt help much either.

[TigerEyz3]

Drone has to do with the overall system length...different harmonic frequencies are magnified/cancelled at different lengths. There's a post regarding this topic in this sub-forum...

[b5visser]

i just got done redoing my exhaust this weekend, and let me tell you- holy smokes what an improvement! I moved the muffler closer to the cat and custom fabbed some pre-bent 180 degree mandrels i got off summitracing.com for like $17 each. I routed the exhaust out before the rear wheels and finished it off with some 3.5in X 18 in SS tips. Looks sharp but sounds soo much better! Its a little more quiet in the cab with signiicantly less drone and yet the tips made the tone much deeper!

This is exactly what i was trying to achieve! Not gonna lie- i was kinda disappointed with the XL at first, but now that I am finished it sounds amazing! I give it props!

[tex2500]

Drone has to do with the overall system length...different harmonic frequencies are magnified/cancelled at different lengths. There's a post regarding this topic in this sub-forum...
yes but that is not the only source of drone. Chambered mufflers rely on the principle of destructive interference by reflecting sound waves off of baffles and and chambers to cancel out drone at a specific RPM range since it is actually the flow rate of of air through the muffler that makes the noise, its called a standing wave. Thats why chambered mufflers have, in most experiences, really bad drone around 1500rpm up through 2000ish rpm and then it almost magically vanishes. That is when the two waves are 90 or 270degrees out of phase and the peak of one wave lines up with a trough of the other and the wave disappears (destructive interference). The exact opposite happens at values of 0 and 180 degrees phase, the peaks of the two waves line up and the amplitude of the sound effectively doubles and you get drone. This is much more common in chambered mufflers because as mentioned above the principle they operate on can only cancel drone at certain RPM ranges.

By the way post some pics please, Im thinking of doing something similar to your setup and hearing your success makes me all the more interested.

[BigTee]

Just my 2 cents. I have the Magnaflow PN 14221 (14 inch body) muffler on my 5.3 Tahoe Z71 and I have no real drone that I can hear (I had more drone with the 22 inch body PN 12588 that I replaced it with. I am not sure why).

I think the muffler I have now is on the quite side unless you are at WOT (then she screems like a Banshee - LOL).