Does anyone know if there is an aftermarket y pipe that goes into 3 inch instead of the factory 2.5 inch?.
I plan on installing a Gibson system on my 03 s/c and I was wondering if the system would flow better getting rid off that 3 or 4 ft of 2.5 inch starting at the the y. I thought about true duals, but I want to maintain some of the backpressure because I do alot of towing and need the low end torque. Basically what I want to do is walk the fine line between optimum lowend power or to much flow and great high end power.
Any suggestions would be appreciated.

 

Check Flowmaster or Magnaflow websites.

 

There is a couple of pics in my gallery of the existing Y which I cut open with a SawzAll. The jagged hole where the 2 pipes join will only pass a 1.6" round object.

There is also a couple of pics of the Flowmaster Y which is in there currently. di/so 2.5/3.0.

I just added 4 pics of the Magnaflow Y to my gallery(waiting to be installed).

https://www.f150online.com/galleries...2504-30794.jpg



http://www.troyerperformance.com/cgi...atalogno=10778

 

Here's another picture of the restriction in the Y-pipe. Keep in mind that some are worse than others.



You can see in ChiDiver's pic that the discolored weld marks surrounding the hole in the pipe represent the true diameter of the pipe.

 

I used the Flowmaster on my old truck. The factory intersection was crap, just like the above picture. If I buy a 3" cat back, I wanted the full 3" intermediate pipe feeding it. It positively made an improvement.

 

Thanks for all the pictures and info. Could Ford have made that Y-pipe anymore restrictive?!.
I think I'm going to order that y-pipe from Troyer...just what I'm looking for.

 

When replacing the "Y" make sure you match materials. I notice the one on troyers web site was aluminized steel.