I am puttin dual exhaust on my 2000 F-150. i called about the exhaust and the guy said that putting two mufflers on the truck would be a waste of money b/c of the fact the way the truck was made with one muffler in mind. He recommended puttin one Flowmaster on the truck with two outlets instead of the y pipe and two mufflers and that it would get the same sound. Any input or things i should know?

 

HI!... 1ST off that guy does'nt know what he's talking about. 2ND stay away from FLOWMASTER mufflers for these trucks. They have been proven over and over again to cost you as much as 7RWH.P. The big restriction in the F-150's exhaust system is the terribly designed "Y" pipe. All of the v8 F-150's exhaust tubing is mandrel bent 2.5" tubing. The "Y" is basically a tube that has a hole cut in the side of it and another piece of tubing is butt welded to it on an angle. The problem is that the hole is usually only about 1-7/8 - 2 inches in diameter. This cause a HUGE restriction in exhaust flow. Mine was only 1-3/4. If you can't afford after market high flow cats then just do a simple custom cat-back set-up. Get yourself a MAGNAFLOW "X" pipe (MF-10791) and two MAGNAFLOW S/S mufflers (MF-14316). If you have a reg cab you will have to weld the "X" pipe to the mufflers, making it as short as possible. Magnaflow mufflers are one of the ONLY after market mufflers that I have seen that actually give power increases instead of costing you power. I have run both the MAGNAFLOW and FLOWMASTER true dual set-ups on my truck and the FLOWMASTER set-up was such garbage that I will never buy another FLOWMASTER product again. After just two years both my FLOWMASTER mufflers rotted out and were constantly cracking and in need of welding. I've had my complete S/S MAGNAFLOW set-up on my truck now for about 8 months and it still looks like new. Also, as for performance increase? The MAGNAFLOW set-up I have now completely and utterly blows the FLOWMASTER set-up away, and in my opinion sounds ten times better. Here's a few pics.

Old FLOWMASTER set-up :

https://www.f150online.com/galleries...-793-37325.jpg

New MAGNAFLOW set-up :

https://www.f150online.com/galleries...-793-29799.jpg
https://www.f150online.com/galleries...-793-29786.jpg
https://www.f150online.com/galleries...-793-29782.jpg
https://www.f150online.com/galleries...-793-37312.jpg

Check out my gallery in the link below to see more exhaust pics. Hope this helps you out.

 

Here's a pic of a factory "Y"- pipe that came off of Jackal's truck. Some have said theirs was better, some have said theirs was much worse. This will give you a good idea of what kind of problem it is on the factory exhaust.

 

I guess I'd agree with Neal, to a point. Here's my $.02 on the topic.

If your truck is a daily driver (like my SCrew), and what you want is a better exhaust note, a little power bump, and a low hassle solution, I'd recommend a MagnaFlow prefab catback setup. I've got their 15609 system on my truck (SISO) and love it. I like the sound, the improved throttle response, and the easy installation (which you can do yourself). The fit and finish of the system is also topnotch.

On the other hand, if horsepower is the main focus of your quest, go with what Neal suggested. Get from MagnaFlow a: X-pipe, a pair of high flow cats, a pair of mufflers, and whatever tubing and tips you need to complete the package, and have your local muffler shop install and weld it up.

For my money, they MagnaFlow prefab catback was the way to go.

And, by the way, I share the same opinion of Flowmasters that Neal does. Never again.

-Mike-

 

I gained as much from replacing the Y-pipe as I did from getting a micro-tuner.
Flowmaster makes the Y-pipe I used, It's 2 x 2.5" inlets/3" out.
I looked on the flowmaster website and can't seem to find it, but FM dealers do carry it.

FM Part # Y-250300A

I had the exhaust shop put the Y right in front of the muffler, extending the 2.5" pipes that come from cats by about 2 feet.

Maybe I lost a little low end torque but the mid/top end is a night and day difference.

I cheaped out on the muffler the first time around but I've heard the magnaflows and that's what I'll be getting to replace what I have now.