Ok so I bought a Magnaflow muffler for my new exhaust system. It's a 3" in/out center in/out. Part number 12249. Muffler case measures 5x8x18 oval 24" overall. Looks high quality and is all stainless steel.

The plan is to have a header with 2" primaries go to a 3" collector, then 3 glasspacks, then go threw the Magnaflow and out the factory tip. Problem is the Magnaflow muffler's a straight threw design! WTF? To me it looks like another glasspack on the inside, but cost a lot more, weighs more, and takes up a lot more space. To all you who run a Magnaflow: Is yours straight threw too? Is it loud? I was expecting some baffling and **** so it would reduce sound. Is this some miracle muffler or what? I'm afraid to even install the damn thing after seeing it's just straight through with perforations and sound deadening material surrounding it.

FWIW, I've heard several cars that run Magnaflow mufflers and they all sounded great. Friend had one on his eclipse and it actually sounded great, but I dunno if it was a straight threw design.

EDIT: Forgot pics

 

I'm pretty certain the Magnaflow muffler on my Enthuza is straight-through. 2.5" all the way from the downpipe back, with a small cat...it's not loud at all.

 

I have a straight through Magnaflow muffler and resonator on my car (with a turbo) and it is pretty quiet, just slightly louder than the stock system. It reduces sound much better than a glass pack type muffler, and of course flows well since it is a straight through design.

I have to ask, why three glass packs? Why not just use a single resonator? Magnaflow makes those as well.

 

the length and size will quite it down...without a turbo it will still be loud, but it will sound pretty badass. Once you turbo the thing, you'll probably only hear it at WOT. if anything it will have a nice low-bassy tone.

 

That IS a glasspack, but only so much of it is fiberglass, the rest is some fancy dancy sound deadening metal fiber, The Borla I have on my N/A NB is straight thru as well and its too quiet sometimes . .

 

magnaflow is not a glasspack...per say

 

Threw = past tense of transitive verb Throw, meaning to propel through the air, as by a forward motion of the hand and arm. Example: "As Chuck threw the baseball towards homeplate with all of his might, Scott could not help but notice the glistening of the sunlight off of his sinewy, muscular shoulders."

Through = adjective, a: extending from one surface to another <a through mortise> b: admitting free or continuous passage : direct <a through road>

Insofar as I'm aware, all Magnaflows are straight through designs. The one that's on my 2.5" Enthuza system passes a golf ball quite nicely.

As Braineack noted, it will be loudish sans-turbo, but once the turbo goes in will quiet down nicely. My system (2.5" Cat, 2.5" Magnaflow, no resonator) is not much louder than stock at idle and light cruise, though the sound is slightly deeper in character. At WOT, it's loud.

I would suggest that three glasspacks in series with the Magnaflow represents unnecessary cost, weight, and disruption to flow.

 

If you're gonna go with a straight thru perf, get a Borla Pro XS. There is no other option.

 

Borla is overpriced. Magnaflow all the way.

order it through performancepeddler.com, get it cheaper than anywhere else.

 

I'm putting 3 glasspacks ahead of the muffler to help quiet the exhaust some. Something has to connect the muffler to the header. Figure it should help some, though how much is debatable. The goal for my exhaust is for it to be quiet. Hopefully similar to stock when cruising and regular driving.

Problem is I won't be going turbo now. Twin SC's is the plan right now, so quiet exhaust will be more difficult.

I always use threw/through incorrectly. Pathetic, but true.

 

mmm turbo and 5x8x18 magnaflow

 

I think I paid $90 shipped for mine. The Pro XS is the quietest out of all the straight thrus, I'll pay that extra $25 for that.

 

I bought the same muffler from Braineack I believe. I threw away the box so can't confirm the part number but it should be the same. I really don't like loud exhaust so I went with this one. I'm running custom 2.5" DP, and 3" exhuast piping without the cat. Sounds fairly decent and not real loud. I might put in a resonator to quiet it down a bit if needed. I just took this video so you can see how it sounds.

http://www.youtube.com/watch?v=GtS8QIXrsZY

 

I have 3" dp straight into magnaflow muffler like yours (straight through no baffles). no cat. i think it's ******* loud. it is wearing on long trips. the SPL is over 100db and I get cranky and argue with my GF. :( i have a swappable midpipe and i may get a resonator because it's ******* deafening. it shoots flames on backfire though so that makes me happy but I can't see them so does it really matter?

 

Here's mine. The exhaust is a magnaflow 2.5" in/out muffler with a cat. Fast Forward to 3:15.

http://youtube.com/watch?v=8HjrOgReY8M

 

Here's my largest-that-will-fit Magnaflow:

http://forum.miata.net/vb/showpost.p...9&postcount=15

 

I have a Enthuza with a magnaflow, and a resonator. It drones just a bit around 3k, and its a bit loud, but much, much quieter than the flowmaster I had before.

 

I am running a magnaflow 5x11x22 with a 4"x14 resonator(magnaflow #12579 and#14419). Its stinking loud with a header and flow thru cat. I need a turbo to quiet it down.

Regardless of the HP you think you are going to make with your system, IMO stick with 2.5" exhaust or don't go with a straight through exhaust. With the above system, which is utilizing the largest mufflers that magnaflow make, I can not hear the engine at all, except at idle. If I have knock, or some mechanical problem, I won't be hearing about it...

Also, 2" primaries for a SC header seem a little large. Sure, you don't want to build something only to have to remake it, cause its not right, but work done by Gibb, suggests that 1.75" or possibly 1.875" are the largest you want to go.. My header, with 1.75"-2.5" collector has a significat torque drop below 2800 rpm, compared to the stock manifold.
http://i122.photobucket.com/albums/o...t/000_0087.jpg

http://i122.photobucket.com/albums/o...t/100_2697.jpg

http://i122.photobucket.com/albums/o...t/100_2695.jpg

 

Good stuff in your exhaust job oreo. Though I'm surprised it's that loud with the cat installed. If you do a turbo, you need to report back on the db drop.

 

Well, I do want it quiet. Already have 3" mandrel builders kit, 2" mandrel kit, and all the 3" mufflers, so it's gonna be 3". The header will be big but my research shows bigger is better for power. Too small will hurt ultimate power at the expense of low end. I have a truck that has low end.

Your pics look good. Is that a gibb header I suppose? Mine will be of similar construction.