I was looking under my 07 5.4l truck to see what the stock exhaust looks like. Finally Ford built a smooth flowing Y pipe. Two 2 1/2" pipes into a single 2 1/2 pipe. I've read lots of posts about true duals & dual mufflers etc. Only a couple mention using a single 3" pipe welded on at the Y but no one seems to have done it. I have no problem running true duals(except thinking dual 2 1/2 is too big 330ci no, 460ci you bet) I would like to know if anyone has run a single 3" pipe off the Y? I was thinking using a SISO Dynomax Super Turbo muffler or Magnaflow 3"in, 2.25" out SIDO muffler. Was going to dump the exhaust out the pass side before the tire. I'm too old for loud just want some performance. Thanks.

 

i have the mbrp si/so aluminized installer series. it is a cat back 3 1/2" system to a 4" tip. sounds awesome. also the after market exhaust systems don't come with performance #s like the ads say. your truck is just louder,and in turn you hit the go-go peddle a little harder and it feels more powerfull. if you really want power gains do headers, highflow cats,and highflow muffs

 

From my research (including friend who operate speed shops) the best performance gain for us is long tube headers (for torque increase). I don't know how cats would work into that kind of set-up though, having looked under my truck too. Other than the stock iron exhaust manifolds, the rest of the system is pretty good from the factory, as you say. High flow parts won't make much difference until high rpms, which isn't where most trucks usually work. I had a Gibson SISO alluminized cat-back on an older truck. That was 3 1/2" I believe, wasn't very loud and outlasted the truck.

 

My cat back Flowmaster system is a 3" SISO from the "Y" rearward...typical of most SISO aftermarket systems.

 

I have a Jeep Grand Wagoneer (360 cu in) that had the same factory setup - 2 1/2 inches into a Y-pipe with 2 1/2 inch outlet to the cat. From that point I installed 3 inch pipe with a stainless Magnaflow 3" in, 3" out, exiting on the right side behind the rear tire (which is where the original pipe exited). Sounds great, but it's LOUD! No inside drone on highway cruising, but it's too loud and a bit annoying for long distance travel - at least for my 58 year old eardrums.

I like my F150 just like it is - nice and quiet.

 

Thanks for the info. I guess what I ment to ask is has anyone cut into the Y, about half way, so the area is the same as a 3" diameter pipe and gone from there. I've seen the single 3" cat-backs but they connect past the Y where it is 2 1/2". I'm thinking that the 2 1/2" area would cause unneccessary back pressure.

 

would a 3 inch exhaust system with true duals, an X pipe and 2 mufflers (all 3") from the 3" collectors on a set of long tubes be too big of piping for the 5.4l?

 

I have stock manifolds that lead to a Y-Pipe I cut to accommodate a single 3 inch pipe with a resonator that exits before the rear tire. Mine is a 7.5L with no cats (F350).

 

Actually, the system you're looking for is basically what I've got.

I had the Y-collector cut back just a bit until it was about 3". Then, I had aluminumized pipe ran back into a DynoMax race bullet muffler.

 

Wow I bet that is a loud *** truck!

 

That is exactly what I was talking about! Did you notice any gains in power or MPG?

 

Well, I did it the 3rd day I owned the truck. Didn't really notice that much of a gain, but I know it has to flow as well as any system out there. There's no restriction. Gets pretty loud and drones between 1800 - 2200 rpm, but sounds real good when you get into it.

 

I did the exact same thing to mine except I used a 4" diesel exhaust off an 04 cummins and I used a 4" Banks muffler I already had. I could'nt tell much difference between this and the Magnaflow cat-back system I had as far as performance, but this has a very deep and powerful tone and with hardly zero drone.

 

@jwiebers:

now THAT sounds like a choice system you put together!

 

@HogTied: Man, your truck is a clean machine! I suppose you don't need to salt the roads in AR for 9 months of the year like we do.