Cat Back or not?

i believe the stock y pipe is dual 2.25 into a single 2.5 to a muffler and out another 2.5 back to the resonator. check out blastin' bobs y-pipes.

Blastin Bob's Fat Pipes

you might want to find out what they're made from, alumized, t409, or t304

Blasting Bob's Fat Pipes are definitely not what I'm looking for. I don't need duals these pipes don't include a muffler and they are made of aluminized steel not stainless. Also I leave for work at 5:45 am and while my neighbors aren't the greatest in the world but I don't want to do that to them. My main concern about changing the muffler is noise. I really like the fact the SE is such a quiet highway cruiser and I don't want to screw that up. I'm still considering an electric exhaust cutout so I can have control when I'm generating noise.

optimal for stock or mild mod engine would be 2 and 3/4 single or dual 2" duals. Single 2.5 is a tad too small, dual 2.25 a tad too large. Also if you want good flow and no drone a fully chambered packed muffler like a dynomax superturbo will do it. Any straight through or unpacked muffler will be a little loud to a lot loud. The single magnaflow system is kinda hollow sounding steady state, and that has three mufflers total and the mufflers are off set in / out so the sound wave will hit the side of the internal baffle before it can pass through the muffler which elimiates or minimize the long wave low freq. drone.

Instead of build your own Y pipes, you could use the 17725 dual in dual out:
http://www.dynomax.com/mufflers.php?muffler=superturbo

This is a fully baffled muffler

oldman said:

optimal for stock or mild mod engine would be 2 and 3/4 single or dual 2" duals. Single 2.5 is a tad too small, dual 2.25 a tad too large. Also if you want good flow and no drone a fully chambered packed muffler like a dynomax superturbo will do it. Any straight through or unpacked muffler will be a little loud to a lot loud. The single magnaflow system is kinda hollow sounding steady state, and that has three mufflers total and the mufflers are off set in / out so the sound wave will hit the side of the internal baffle before it can pass through the muffler which elimiates or minimize the long wave low freq. drone.

Instead of build your own Y pipes, you could use the 17725 dual in dual out:
Dynomax® Performance Exhaust | Mufflers | Super Turbo™ Mufflers

This is a fully baffled muffler

Click to expand...

The only downside to the Dynomax Superturbo that I can tell is that it's aluminized. I was looking at the Dynomax Ultraflow 17234 just to replace the Flowmaster's muffler and keep cost down, but it's a bit longer than the Flow's 50 series which would force a major cut in the existing Flow's dual out pipes. I found a Magnaflow universal SS 12268 single/dual 2.5 that might work... I'm not sure if it will minimize the low freq drone, but it is packed, which should help. Not much I could do with the 2.5 dual out pipes other than getting rid of the Flowmaster entirely and go cu$tom.:argh:

Dynomax® Performance Exhaust | Mufflers | Ultra Flo™ Welded Mufflers

the ultra flow is a straight through design so it will be loud and depending on the offset won't do much to negate waves, of course I got no idea how the inlet is split to the outlets:scratchhead:


MagnaFlow Exhaust Products - Exhaust Mufflers For Trucks, Suv's, American Muscle, Diesel, & Sport Compact Vehicles

is also a straight through design of course once again single in to dual out dunno how the split looks. The center flowmaster that you have is already a chambered but not packed muffler, all in all I'd say for sound control it is really 6 of one vs 1/2 dozen of the other:scratchhead:

The flow master is just painted metal (I know it is thick) or is it SS and / or coated? The dynomax is a much cheaper in construction, I guess the figure the packing is going to be dead in 5 years anyway so who cares if the muffler case will rust out in about that amount of time?

The ultraflow X looks good
http://www.dynomax.com/mufflers.php?muffler=ultraflox

I'd limit it to 2.25 pipe dual in, it has a built in X pipe and run the two flowmaster rear muffler/ resonator tips. I have NO experience with the muffler but looking at the X I would assume it would be harder for long waves to pass through the core as there are two angles to traverse and the center is of the tube will get pulses from the other side.

tf34mech said:

Joeyv123 was right about the pipe diameters so I amended my parts list:

Magnaflow 13266 XL Stainless Steel 2.5" Oval Muffler | Beanworthy

Amazon.com: Magnaflow 10758 Stainless Steel 2.5" Exhaust Y-Pipe: Automotive

Click to expand...

13266 XL is nearly identical internally as your stock muffler, just not as good as the stock.