The stock muffler on the 2009+ outflows a Flowmaster. On my 2008 I put a Flowmaster Super 40 SI/DO Lightning style and it robbed ALL of my low end torque. As soon as I put my stock exhaust back on I got it all back.

 

Inlet/outlet on your stock muffler is 2.5/2.5 Loki. So you could easily swap s Maggy or Bullet to get those low end power gains you want for towing.

 

My pipe going in measures 2.5 O.D. and 3.0 O.D. coming out (with calipers) . I am going to go with the Borla as it had the best low RPM torque & HP numbers and did not give up anything on the top end max HP and torque numbers of any of the mufflers I saw. I am going with the turbo XL instead instead of the XS since I am running a single instead of duel exhaust and can still remove the resonator if I want louder.
http://www.mustang50magazine.com/tec...o_numbers.html

 

I have a 2011 F150 with a magnaflow muffler sido, i had the exhaust shop run the 3 " pipe from the y pipe back into the muffler than dual 2 1/5 in tail pipes 90ed behind each tire. I removed the resonator. I think it sounds damn good. Not to noticeable at idle and the more you dig in to the throttle the louder it growls.

http://www.youtube.com/watch?v=ssM-zyMMbi0

 

sorry only noticed a gain on my 75 bud

 

Here is a pic of the stock y pipe [IMG][/IMG]
look at how small the pipe gets too were the resonator clamps to the pipe.[IMG][/IMG]

 

I have looked under mine , I thought the Y didn't look to restrictive, the clamp step down did not seem as drastic on mine, I guess I will take another look and drag a caliper out when it stops raining, now snowing outside.

 

ya but the y looks more like a t not the greatest for flow.

 

i'm sorry if i sound stupid and i'm going to try not to but i changed out my stock muffler with a SI/SO maggie. I dont really know what the resonator does so my question is as follows... I'm not extremely happy with the sound from the swap so if i had the resonator cut out and replaced with just pipe would it make the sound throatier or raspier?

 

Yes it will make it loader to.
Exhaust resonators are usually add-on features in exhaust systems. They are placed together with the mufflers along the exhaust pipe and work primarily to decrease exhaust noise. The exhaust noise passes through the resonating chamber, which in turn tunes the sound to cause destructive interference in order to be canceled out by the opposite sound waves.

Read more: What Is an Exhaust Resonator? | eHow.com http://www.ehow.com/about_5765675_ex...#ixzz1GpCql000

 

Bleedingblue sounds great! Any problem passing state inspections with your setup (resonator removal)?

 

I have a 2 year safety inspection on it from the dealership. There shouldn't be an issues. I had them do it so the exhaust still unbolts in the stock location after the y. I think it looks almost factory except for the fact I have 2 tailpipes.

 

Has anyone removed the resonator and left the factory muffler in place?

 

^^^^^^


When you get that stock can off tell us if its a straight through like the 2009-2010 models.

I've had a look at a few 2011's and they seem to have a different setup.

Its a resonator then a Bigger than the 2009-10 models, and it looks like its offset, which tells me its probably not a straight through.

I"d like to know if you could post back.

 

Well here is the stock 2011 5.0L exhaust. That muffler is 27"


[IMG][/IMG]
[IMG][/IMG]