I'm sure there is more than a few knowledgeable people on this forum that can help me out. I have an 08 5.4L FX4 and I'm planning on putting an exhaust system on my truck. Just a cat-back type, nothing really outragous. What I want is a SI/DO muffler that will give me a nice growl when I stomp on it but also is fairly agressive sounding when driving around town. I still want it to be fairly loud when idling too. The cat-back kits on the magnaflow site all use the 18" muffler which barely puts out any sound so those are out of the question all together. My dad has the 18" on his 2000 5.4 and you would never know it has an aftermarket muffler. Also before anyone suggests another brand let me just say that "IN MY OPINION" magnaflow sounds the best. The videos I've watched also seem to show that they don't have the horrible popping noise which again is "MY OPINION" (not trying to **** anyone off).

So to cut to the chase, I was thinking of getting an 5"x11" SS oval muffler. Keep in mind I will have a stock intake and stock headers and all original cats. Is this gonna be what I'm looking for? Will there be any popping or will I need to get a tune to fix that? Would the 5"x8" be better? I will eventually get a set of long tubes with high flow cats and a new intake later on.

A good comparison of what I want is something quieter than my brothers lightning which I believe has the dynatech LT headers with high flow cats and two straight through round race mufflers but at the same time louder than a stock lightning. I know we are talking about two different motors here but its the best comparison I can draw.

 

You sound like you have a great knowledgable choice and know what your talking about

The 5x11 body? thats a 22" muffler, if you meant the 11" body, those are 4x9 cases and only available in SI/SO or DI/DO. I have true duals using the 11" body SI/SO mufflers with a couple less cats and a custom tuned truck but generally all stock. I love them. My videos are in my signature.

 

i have dual 14" round bodies. but they are only SI/SO.

you sound like you would like the 14" oval body in SI/DO

 

Shoot sorry. For some retarded reason I didn't see the specs for those mufflers. Note to self lay off the crack. I'll try and see if I can find a video or the 14" ovals. Darren I seen your videos, sounds amazing. I'd love to have the close to the same but that would be hard to do considering I'm not gonna get a true dual system. About the right amount of idle loudness and cab noise though. Well done.

 

Oh ya, one other question. If I'm running a SI/DO would I be going for a 3" in 2.5" or 3.5" in 2.5 out? Keep in mind I don't want to open up the exhaust too much that I start trading torque for hp.

 

You will want to run 3" in. No larger, or smaller. 2.5" tailpipes will be perfect for it. The part # to the 14" SI/DO you would need is 12198.

 

not sure why you say no sound but my 18in catback has gottin much louder and sounds really good now.

 

Well I'm just speaking from what I know. Maybe yours does but I know my stock exhaust is louder than my dad's magnaflow at idle. The only time I really notice my dad's is when you really get on the throttle.

 

Hey Altatruck, just order the muffler Darren gave the part number for and you'll be fine.. in fact, order two.. i'll p.m. you the address to ship the extra one! j/k...
That's exactly the muffler i am ordering.. one day. Going to finish it off the a Harley Davidson exhaust tip...

 

Go with the 14" round bodies and some cats. It's got a nice roar when you get on it, you can hear it at idle but it's not too loud. I think it's perfect. Check the links in my sig for some videos of my setup.

 

Nice set up cashel. I too am a big fan a big tire small rims (not to mention the bomb proof 2V motors, so much low end torque). My truck will never be anything like that though. True duals are out of the question and I'm not gonna put a lift kit on it. Maybe a leveling kit if I ever feel like throwing money around to get bags put in the back at the same time (to avoid the the racked back look). I'm surprised no one has uploaded a SI/DO 14" muffler clip. As for the cats, well I'm gonna leave those until I get my headers which the kit from dynatech comes with 2 High flows. All that is after the warranty expires mind you.

 

Youtube is the best source for exhaust videos.

http://www.youtube.com/results?searc...Magnaflow&aq=f

 

Ok, I've been following this thread and a few others for a bit and I've got a few questions. Is the 14" body louder than the 18" body?

I'm planning on purchasing a Magnaflow muffler (SI/DO) very soon but every time I look on the website I realize I don't know which muffler to buy! We have a 2.5" inlet, correct? And since I'm splitting it into DO should I increase the outlets to 3" or leave them at 2.5", or perhaps even drop them down to 2"? As far as the tips go I've seen people recommend 3.5" diameter, 18" long tips. But I've also seen some recommendations for the 4" diameter, 14" long tips. What's the difference between the two in tone?

I'm sorry for semi-stealing the thread but a few of my questions apply to this thread and I didn't want to start another "newbie has questions" thread...

 

Shorter the muffler the louder it typically is. Particularly in terms of magnaflows as they are a straight through design. They don't have baffles and junk in them. I believe we have a 3" in and would go 2.5" after the muffler. Any question pertaining to the thread isn't stealing it so don't worry. As far as the tips go they will have no effect on the sound, speaking from what I know.

On another note, how different will the sound be of a 3V 5.4 versus a 2V?

 

wow, just watched a bunch of those videos that darren sent the link for. I'm SOLD!!!!!!!!!!!

Now all i need to do is get the drivetrain vibration/noise fixed and I'll be ordering one up.