Speaking strictly performance wise, what would be the best brand to get, and what kind of gains could one reasonably expect? I've had some people tell me the gains are minimal at best, others say its worth it in conjunction with other parts and advertisements make them look like Gods gift to power.
So, whats the honest, no BS answer?
Thanks,

 

15609 is the best bang for the buck- noooooooo torque loss- that with my mac intake and 9100 tuner has really made my truck ann animal-phil

 

If you want any real power gains from your exhaust you need to get ride of the 4 cats and put 2 highflow cats in their place. It is a little pricy to get this done but it sounds great and really helps in performance.

I think that w/ putting after market mufflers on you gain about as much as you would w/ a k&n drop in filter.

On mustangs if you replace the h-pipe w/ a x-pipe w/ 2 highflow cats and some different mufflers the gains are close to 30hp at the wheels.

On my old 2002 stang I had the x-pipe w/ 2 high flows and mufflers, cold air intake, pulleys and 3 degress of timing advancement. I was putting down 259.7hp to the wheels. stock they put down about 220hp to the wheels. The pulleys and timing advancment are only good for a few extra ponys.

 

I planned on swapping cats as well. If that something you can do yourself or do you need to have the old cats cut out and the new ones installed at a shop. I have no welder so I pretty much need "drop in" replacements.

In the end I'd like to run hi flo cats, cat back, intake, underdrive pulley and chip. Forced induction is definately on the list, but that has to pass the spouse acceptance factor, which is low when it comes to go fast toys unfortunately

 

Generally, the high flow cat setup is a custom job using universal weld-ins and muffler shop piping tools. What kind of truck is this?

 

1999 Expedition 5.4L
I'm appy with the on road performance, but once its off road, particularly in deep or soft sand, it just doesnt quite have enough oomph to make me feel comfortable. I'd like to end up with right around 50 more ponies once I'm done.