Right now I have on my 4.6 05 f150 si/do flowmaster 40. I want to go with true duals to try to gain some power (not extra noise). I need something that is going to give me tq. So please feel free to rep your brand make sure to include details such as pipe size, type of muffler size, series, etc. Any suggestions will be greatly appreciated and considered with an open mind.

 

I would cut off the stock Y-pipe, put an X-pipe there and then run 2.5 inch true duals with Magnaflow mufflers. If you want the same volume as your 40 Series go with the 14" Magnaflows. That will give you some power and restore the torque.

 

i would go 2.25-plenty big for a 4.6,i went for tq-i gained some on bottom and the 2.25 was plenty size for mid and up gains-my .02$-phil-ditto the x pipe!

 

2.5" dual into a pair of Flowmaster 40's. You already have one, why not save the cash and just buy one more instead of two new ones? And I still don't believe that load of malarke that I am loosing torque with flowmasters, and I wouldn't believe it even if God himself sat me down and said, "you know, get a better muffler and you'd get another 2 lbs of torque." Well, to loose that flowmaster sound for 2 or 3 pounds of torque ain't worth it to me, even if it was true.

 

Hey 98Navi, one thing I do agree with Troyer about is Magnaflow. Definitely the best for our Fords! Ask him if you don't believe us!

 

I think youll lose torque with a true dual setup. My friend put duals on his 5.4 and lost a lot of torque coming from a SI/DO FM40. He put two SI/SO and it sounded better but lost low end torque. 2.50 pipe size. My 2 cents

 

5.4, you fail to tell us if your friend has a dyno built into his azz or he is just guessing or you are just guessing. The only way to tell is to dyno before and after. And I'd bet the numbers would be withing just a small range of one another.

fourpointsix, I know Mike likes those crummy shiney yuppie mufflers (no offense to you of course) and had a certain amount of disdain for my preferred SUPER MUFFLER, but I just wouldn't give a dime for those stainless wastes of money. Dont like the way they sound, had issues with them years ago when I had one, and they used to be a cheap off the shelf muffler from pep boys and the like. Flowmaster never was an off the shelf cheapo.

 

i put true duals,x-pipe, and magnaflow 4x9x14 mufflers on my 8000lbd 3/4 ton van-i used 2.25 " to keep tq-
1- i gained some bottom end tq up to ~2500 rpm-after that ,all hell breaks lose- great power gains up to 5400 rpms-VERY,VERY pleased!-phil

 

magnaflows!!!

 

Well first you have to decide on what you are wanting in an exhaust. Sound or power increase. And according to you question, you're looking for a good sounding system with an increase in torque.

I'll step up and vote for Magnaflow. Yep, they're not the loudest exhaust system on the market, however based on engineering and dyno results, Magnaflow can state that they are one of the top exhaust system companies that produce a significant increase in hp and torque throughout the rpm band.

For the most gains, the SI/SO 3" system is the choice for NA Ford trucks. If you're wanting the dual system look and sound, then 2.25" pipes will provide a gain, but not as much as the single 3" system. Run 2.5" true duals, then you might loose a little torque and that's something you don't need to do on the 4.6 engine trucks.

If the engine is blown, then by all means install a true 2.5" dual exhaust system.

 

[QUOTE=crazyaboutF150]Well first you have to decide on what you are wanting in an exhaust. Sound or power increase. And according to you question, you're looking for a good sounding system with an increase in torque.

I'll step up and vote for Magnaflow. Yep, they're not the loudest exhaust system on the market, however based on engineering and dyno results, Magnaflow can state that they are one of the top exhaust system companies that produce a significant increase in hp and torque throughout the rpm band.

For the most gains, the SI/SO 3" system is the choice for NA Ford trucks. If you're wanting the dual system look and sound, then 2.25" pipes will provide a gain, but not as much as the single 3" system. Run 2.5" true duals, then you might loose a little torque and that's something you don't need to do on the 4.6 engine trucks.

i ran the 15609 3 " siso on my 03 4x4 5.4 supercab and now a 2.25 x-piped true dual setup on my van-i would chooses this setup in a heartbeat over the 3" single-more tq and hp-and my van weighs 8000lbs-my .02$

 

You can't compare the 5.4 engine torque to the 4.6 engine torque. That's like comparing apples to oranges. The 5.4's can be affected by different exhaust setups as far as loosing or gaining torque, but it is more noticeable with the 4.6 in these trucks.

I have tried 3 different exhaust setups on my previous '00 F150 SC with the 4.6 engine until I hit the right combination. First system was Gibson cat-back system split rear SI/DO 2.5" pipes. Helped in making more power and torque, but quiet sounding. Second system was to only remove the Gibson muffler and replace with a Flowmaster 40 series. Lost bottom end torque, not sure about hp, and got an anoying cab drone. Too loud! Third system, I went with the Magnaflow 2.5" DI/DO true duals which eliminated the 'Y' pipe. Gained bottom end torque and increased power.

With my '02 SuperCrew (HD clone), I installed the Magnaflow 3" SI/SO after a lot of investigation on a system that would create the most power/torque out of the NA 4.6 engine. Now, 3 years later and having less than 14K on my truck, I'm changing the system to the Magnaflow HD true dual system to go along with my supercharger.

 

Flowmaster 40's all the way. I read all these claims of torque loss or increase it's hard for to grasp that installing a Magnaflow can actually affect the tourqe to where someone could notice it. Get a before and after dyno then i will believe you. Also you can't beat the sound of Flowmaster

 

Flowmaster 40's all the way. I read all these claims of torque loss or increase it's hard for to grasp that installing a Magnaflow can actually affect the tourqe to where someone could notice it. Get a before and after dyno then i will believe you. Also you can't beat the sound of Flowmaster