hi folks,

in researching for my 2001 Screw's conversion to dual exhaust for its 5.4L, i was surprised to hear that if i dont get a crossover
that i may lose some performance.

some guy my brother knows(and holds in some esteem) says
that if i dont have a crossover, i may lose backpressure and
actually hurt my performance.

as this is an exhaust specific query, i posted here rather than performance group. i see that many of you have converted your
single exhaust to dual, has this been a problem/issue for you?

all feedback appreciated, jackc...

 

Just get a Magnfloaw X-Pipe and use it to replace the stock Y-Pipe.

 

I will not go into much detail as this has been discussed a lot before and i'm sure you can find plenty of info on it.
First I would like to see someone who has been able to directly replace the Y with an x-pipe. Most have had to add sections of pipe then the xpipe.
The general idea is that an x-pipe works best in a equal length exhaust system. Which is hard to impossiable to do on the current F150's. The idea is that exhuast pulses from each bank of cylinders should meet the x at the same time. This allows them to mix smoothly and create sort of a vauum pull to sort of suck out the next pulse of gas. Yea you might scavage some exhaust but it's not going to be a huge differences. The x-pipe is not needed to keep backpressure if the exhuast is properly sized. Running true dual on a stock to mild 5.4 I would use 2 1/4 maybe 2 1/2. If you stay with the smaller pipe you should keep most if not all your low end. You also need to think about what type of muffler you plan to use, some are more restrictive than others and I know most people are looking for a certain tone.
Don't get me wrong I would love to have an x-pipe system. I just think they have their proper place and type of installation.

 

You want to do something like this


This is a Magnaflow X pipe and 2 magnaflow mufflers.

Enen though I have a Lightning I am sure you could do something very close to this on any F series truck. Just cut the pipe close to the Y, you may have to weld two short peices of pipe ti get things to line up right. Then weld in the X pipe and put the two mufflers together, and then just run two pipes out the back.

 

Opps sorry I forgott to show a rear view.

You can either have it come out the side like mine, or run the 2 pipes out to the rear if you want.

A lot of the Harly guys that have done the same system as me, have the tips exiting infront of the rear wheel. They say it with the shorter rear pipes they get less drone.

 

Jack

Here are some pics of the dual exhaust on a Harley Supercrew

Using the magnaflow X pipe Magnaflow mufflers and tips.

I think this will work awesome for you.






here is the link where I found it
http://www.svtperformance.com/forums...exhaust+system

links to Magnaflow
http://www.magnaflow.com/03cat-back/...nlesssteel.htm

http://www.magnaflow.com/03hardware.htm

 

Those are both nice looking systems, but they may be too much for a non supercharged truck?? I bet it sounds WICKED though I have my mufflers as far back as they can go(before the axle) and I still hear them while on the highway. How noisy is that system with no floor insulation to help out(On the Lightning)?,,,,98

Don't get me wrong, love the way that looks!!!

 

Well here is another option
Magnaflow 14468 it has a built in crossover inside the muffler.

 

opps ment to edit my earlier post

 

I think I just found my new muffler! Do those come in a 2 1/4"I/O??? Right now I have two glasspacks that the installer welded together as one muffler, looks like a rust through waiting to happen?D How much do those run price-wise?,,,,98

 

they make a few 2 1/4

oval
2.25" part #14315

2.25" 14" 20" 14215


here are the round ones
http://www.magnaflow.com/03cat-back/...steelround.htm

 

I know this has been discussed before but I am unable to find the information I need and maybe you could help me out. I plan on doing a true dual exhuast like yours on my truck. I also need to replace the cats. I am thinking I should change the four cats with just two hi-flow ones...run the pipes into a x-pipe and then into a di/do Magnaflow muffler. My question is what happens with the O2 sensors....how do I get these to adapt to this new setup??

One of your pics looks like exactly what I want to do. It looks like the right hand side pipe come directly out of a replacement hi flow cat and into the mufflers (I would use an x-pipe before this though).

So, could you give me any info??

 

Why do you need to replace the cats??

I wouldn't mess with the cats unless you are doing some very major engine mods.

But here is the info

You can get bungs that the 02 sensors screw into, that can be welded into any exhaust pipe, sometimes you need to get a extension fot the O2 sensor. I know JDM can get you the extensions. His # is 732-780-0770

I see you have a 4.6 motor. I had that motor in my last truck. If I were you I would get a single in dual out Magnaflow, or if you want a dual in and out, I guess thats ok. Don't mess with the cats unless they are bad. The 4.6 motor likes some back preasure. I made the mistake of going with to free flowing of a exhaust system and ended up pulling it off for something with more back preasure.

I will crawl under the truck tomorow and post some pics of the relocated 02 sensors. It may take till monday or tuesday to post the pics, I am going to a car show tomorow.

 

Thanks Don, the reason I wanted to replace my cats is because when I had the motor rebuilt the guys left the 02 sensors unplugged which I beleive was dumping unburnt fuel into them. I now on occasion get that bad smell from a catalytic converter. I was thinking if I was going to put on a new dual exhuast (si/do Gibson was my original plan), why not replace the cats and run a true dual. But, it is nice to hear from someone with some experience with a 4.6L and a too free flowing exhaust. I am now thinking, like you suggested, running a si/do setup to maintain backpressure. I plan on no major mods...just AF1 intake, superchip, exhuast, and 4.10 gears.

Does Magnaflow build a si/do split rear for these F150's??

Do you think I should put on the new exhaust and then decide about the cats (the exhaust right now seems awful quiet and quite restrictive)??

Again, thanks to responding to my posts...I look forward to the pics and enjoy yourself at the show

Thanks, Matt

 

Don's Bolt,
Where did you find the tail pipes from behind the mufflers out the side? The picture looks like you have side exit.
I want to put togeather a custom combination for my exhaust but I am having problems finding pre-bent side exit pipes for behind the mufflers.