I'm looking for an x-pipe to put on my 98 F-150 4.6l . I was wondering where the best place to get one is. Thanks for the help.

Could someone also explain the whole back pressure theory. I know a lot of my buddies run open exhaust on their stangs except for the Flows and it doesn't hurt them any. Thanks in advance for the help.

 

First off, this site has X's, Y's, and quality mufflers:
http://www.magnaflow.com/

As for backpressure, at lower RPM's cam timing will often have enough overlap that the exhaust cam is still slightly open when the intake cycle starts, thus allowing some charge to be sucked out with exiting gases. If there is even a slight amount of backpressure, it can prevent some of that lost charge. For your stang friends to say they haven't been hurt by it, they either have very crappy cams in their cars or they don't know they have been hurt by it. That is where proper pipe sizing and things like X pipes can help prevent these loses while still giveing you close to optimum gain on top.

 

Where you going to put one?

A X pipe is for true dual exhaust like the Mustangs have. It would take so many extra bends to get it to fit, you would kill the benefit of one. Unless you take 2 pipes, cut a section out and then weld them like the Dr. Gas pipes.

If you run true duals on a 150, you run them down the same side as stock. The passenger side. You split the Y pipe and go back from there. Install a equalizer (like H pipe) in there and you are good to go.

 

Actually, with a true dual set-up, it is not diffifult to get an x-pipe installed without any bends other than a 90 degree bend from the drivers side to the x-pipe (this 90 replaces the y-pipe). The passengers side pipe is a straight shot into the x-pipe. From the x-pipe to the mufflers, another straight shot. And from the mufflers on back out the truck, it is no different from any other set-up. My set-up uses the Magnaflow x-pipe.
GDG

 

Hey godoggo, sounds like you've done almost exactly what I want to do next weekend. I've got the HD so I'll be retaining the stock HD tail pipes, otherwise true duals with X pipe and Magnaflow mufflers (2). Do you have a pic of your X pipe install. I'm curious how they handled the 2nd O2 sensor that was in the Y. Did they just make a short extension of pipe and weld a bung in it for the O2? I'm assuming that's what they are going to do with mine. Just curious. I'd like a pic for reference before I go into the shop next saturday.

 

I'm just beginning to catch modification fever but, you sir, are on a different planet. I can't even figure out what half that stuff on your truck is and what it does. Hopefully I can figure some of it out doing searches. Does it all really work and do yo have any pictures of any or all the mods?

 

Hey guys, thanks for all of your help, and the explanation.

 

Hey Irutt,
I really like the new exhaust mod. I used 2.5" pipe all the way, except for the 3" tips. I was worried that I would loose low end torqe since the exhaust was opened up so much over the SI/DO I had previously, but I actually gained some on the low end. I think the x-pipe helped a whole lot on restoring any potential low end losses that a 2.5" dual system might give over stock. The exhaust shop had no problems with the O2 sensors since they were all before the Y-pipe. The closest O2 sensor was on the passenger side, about 10" or so before the Y-pipe. On the drivers side, the O2 sensor was well out of the way. The shop used a cutting wheel to remove the Y-pipe leaving about 6" of the stock exhaust pipe after the O2 sensor. The new pipe was MIG welded on the stock pipe with about a 5" clearance from the O2 sensor. I asked the welder if he would remove the O2 sensor before welding, but he didn't think the heat buildup would be a problem. I believed him, and after watching him weld I know it wasn't a problem (he was a very good welder). Depending on how close your O2 sensor is to the weld and who does the welding, you might want your man to remove the O2 sensor first before welding. See what he thinks and you be your own best judge. Sorry, I don't have any pictures since Santa never brings me a digital camera - I need to get one though. Hope this helps you.

Screwdriver,
Believe me, ther are many others here that are more knowledgable and have done far more mods than me. For example, check out Neal (the HP "Freak"). It is sick what he can do with a truck. Frankly, many of my mods were based on his ideas. Do the mods work - oh yeah. Far more torque than before - and the best part is that my mileage has improved by about 2mpg over stock!!

GDG

 

GoDogGo,

Must be the fact you have a 4x4. My second O2 sensor is right in the Y pipe. That is the only thing I can see being an issue with the guy. He noted it before though and still said we can do it so I'm going to go for it. I will have him remove the sensor before welding though.

 

Spintech makes an x-pipe assemble made just for them!