Magnaflow 2005 F150 4.6 Exhaust Help
 

It's time for me to replace my exhaust because my muffler is rusting through and the exhaust pipe is also falling off because it got bent a year ago. The current muffler is a flowmaster wanna be. No brand name on it or anything. It has a little too much drone in cab anyway. It's hard to hear my son in the back seat sometimes because of it.

Anyway, I have dual pipes into a dual in dual out muffler at the moment. I believe I'm wanting to add an x pipe and do dual single in single out. I'm looking at magnaflow mufflers and I was having a hard time deciding between 14 and 18 inch. I believe I want an 18 inch so it will sound good at start up and when the pedal is punched but I would like the cab to be relatively quiet. It's hard to find videos online because people don't say exactly what muffler they have though. Would a magnaflow #12646 18 inch 2.5/2.5 muffler be what I'm looking for?

Will it sound good under throttle but quieter at cruising speeds/idling?

Thanks in advance

I have a SISO 18" magnaflow but it is not a straight through design , more offset...it is pretty tame... But not bad, it works for now and for me.

Its my understanding that if you get a straight through flow it will be more aggressive under the conditions you're looking for. This is pretty subjective your aggressive maybe too much for me or vise -versa. but I get the impression that the DIDO mufflers are louder by inherent design, so a X pipe infront of it may tame it down some, at least smooth it out

If I had to do it again....I'd probably talk directly to the manufacturer of your choice or a good muffler shop and see which one suits you best

have you read through this>>https://www.f150online.com/forums/ex...ust-guide.html

Yes, I have read through that 3-4 times. That's when I decided to add the x pipes. My current rusting out set up doesn't have one. Some threads on this forum have said not having the x pipe will hurt performance and mpg. It'd be nice if with the new set up I do get better mpg but on another thread someone acted like that was completely not possible.

I would say it is more about driving style then your exhaust set up. Sure you can loose some here or there with a bad leaking exhaust, or maybe gain a bit with the right system. BUt my feeling is that anyone who likes to hear their exhaust is not going to get the most efficiency in MPGS....it just begs too much right foot activity.

An 18" body will help tone down the interior tone. A Borla ProXS in 19" case length will be equivalent in results inside, and a bit better sounding outside.