I have been reading the forums extensively over the past week and here is the conclusion I have come up with on exhaust. Many feel that cat backs help the top end but kind of hurt the low end (like too big headers). The one stated exception seems to be the Gibson systems. There seems to be varied opinions on single vs. duals.
I have an '06 Scab 4x4 with 5.4l. It is everyday driver and will be used for occasional towing duty. I plan a chip, CAI and exhaust upgrade in the interest of better throttle, less constipated acceleration and better MPG, heavy emphasis on the MPG. It has very little road noise and quite cruise and I want to keep it that way but I wouldn't mind a little V8 rumble when I start peddling fast or a mellower sound when idling. Low and mid range are more important than top end at this stage of my life. I went through a series of high speed runs in Mustangs in my early years and I no longer have the nerve to tackle 130 mph in a 4x4
Having said all that, what would some of you folks suggest in an exhaust system. I know that some of the systems that are complained about as being to quite might be just the thing for me.
Mid range over top end
No droning noise
Mellow over roaring
MPG and HP increase

Thanks for the advise!

 

3 words
Mag na flow

 

Ok, no doubt good advise but can you qualify it: why Magnaflow vs others, power band, personal experience? Which model/size, single vs dual.

 

With the Magnflow, if is more quiet when idle or travelling w/o a load. Once the engine gets a load during acceleration, the muffler really makes a nice solid tone, nothing on the extreme end of loud but it is certainly noticed. I have a 16614 SI/DO.

I don' think you are going to get any 'regain of cost' in MPG savings.

I don't have any experience with driving a similar truck with different exhaust systems. I can feel in my seat a noticable difference but probably nothing really significant on any recorded graphing.

General consensus that the low end torque does not dissapear with a MF system. I have a S&B CAI and I can really feel the truck still pulling once I get to higher RPMs as well as over 50 MPH from stock.

I had a FlowMaster on a Camaro YEARS ago and honestly it was too loud. My girldfriend could hear me coming a block away. I had a strong buzz with my S&B and solved it. I had a bolt under it that I had mounted my alarm siren. Removed it and it is much nicer but does make a strong rumble inside when at WOT and I kinda like it.

I still only had it to 90 MPH to feel top end pull.

 

If you like them loud - just get the magnaflow 14" Muff

There loud , if that's what you want.

I'm not sure - if you run the 14" - you have to have duels , but there still loud..

 

Thanks for the reply. I am surprised that a bunch of others haven't waded in on the issue.

 

well by the sounds of it a magnaflow catback with an 18in muffler would be good for you.

 

Here is some good reading, and what you may be looking for.

I went this route to save some money.

 

I have heard many great things about the maggies. If you dont want to dual it out, JBA has been spectacular for me. You can immediately feel and hear the difference. THe polished stainlees steel rcat back runs about $315. The muffler is polished and beautiful with a nice K&N stamp on it and the tip is polished as well with the JBA logo. As far as I can tell the low end is about the same, however you can really tell in the throttle response the difference. It feels like a different truck. The sound is exceptional. It isn't noisy in the cab but she is a head turner when you roll by. Sounds like a big block instead of a 4.6.
When you go to pass on the freeway the flow is exceptional with a fantastic linear pull to the speedo cutoff. My mods are listed below.

 

I put a dual out Gibson system on my '01 crew. The fit was nothing to brag about especially on the dual out part. It also had and still has, though to a lesser degree, an annoying drone inside the cab. Especially for those seated in the right rear seat. On top of that, no noticeable performance gain. It does sound decent and the dual chrome tips look nice.

 

First of all, yes Flows can have a great sound but they are baffled mufflers, not a straight through. That's why they can actually, if not rob torque, then make no better than the stock muffler. They sound feakin' cool tho..

I have to say that I put on a Borla SI/SO and I love it. Nice growl, not obnoxiously loud, tho it is getting a bit louder now that I have a couple of thousand miles on it. Gained 1.8 mpg highway as well. Can't feel any hp gain if it's even there. The sound and extra mpg are worth it though I think.

Borla manufactures the cat-backs that Roush sells as well and for some reason they are a little less expensive. I wish I'd known that to begin with, would have got a Roush!

 

i had a buddy with borla exhaust on his 2004 f-150 and it was a really smooth exhaust. it was really nice for a every day truck...

 

The items that you want in an exhaust describe the Roush LEGAL Exhaust System exactly. I did a ton of research before I decided on this system and I cannot be happier with it.

No interior noise, throaty but mellow sound, complete T-304 aricraft stainless (not the cheap 409 grade stainless Magnaflow uses), killer looks, etc....

And the system is made by Borla.

You will love it.

 

I'm in the same boat as huntingKY with exhaust requirements and it seems like the Roush LEGAL Exhaust System or Borla is the way to go for me. Now what is the performance difference between SI/SO and SI/DO? I imagine that the dual out sounds louder and looks tougher, but is there any other advantage to the duals?

 

How would true dual side pipes with flowmaster 50 series delta flows sound?