What's the GAIN?

[Conn]

I've got a 01 Expedition 4x4 5.4L, I (not me, my mech.) installed Gibson ceramic headers, exhaust, a throttle body spacer, and I got the Hypertech programer. I left the stock cat-back.
My question is, what's my gain in HP, FT, and MPG? Does anyone know?

 

[monsta]

You probably got about 30-40 more HP to the rear wheels @ 5200 RPM. (WAG)

Curious...why would you make all those expensive exhaust mods but keep the stock muffler and tailpipe?

 

[Conn]

I thought i added the exhust, I have the gibson exhust and pipes
Thanks

 

[smo0othride]

On the mpg you might not have gained much. Some chips actually use more gas then stock, which is how they give your engine more power. With the improved exhaust it probably about evened it out.

 

[baller baller]

but the thingy with the programmers is you can adjust the chip to what u want like lets say for towing, or change it for cruising or whatnot so actually u save gas with them babies by doing the economy switching

 

[stang99x]

Well, its hard to estimate. Some vehicles reactly differently than others. When you say exhaust and headers, do you mean all of it or cat back and headers and what size pipe did you use? What kind of muffler? (gibson I would assume) I know it seems trivial but it is all relevant

Figure, if you replaced the whole exhaust with 2.5 inch, added high flow cats, and a decent flowing muffler, you added 6-12 HP.

As for the TB spacer, I got one of those two and found a basic nill response. We'll say 1HP

The hypertech programmer; which program, the 87 or 93 tune?
Assuming the 93 tune (or 91 whatever it is) was used and we'll say an average gain of 8%. Thats 21 hp on a 265HP motor

So, add them all up, maximum increase of 34HP. Most likely around 25-30 HP.

All that money you spent on a gibson exhuast and you could have just about bought a blower. If you are really serious about performance, watch ebay for an F-150/Expedition/Navigator blower to go through. I bought mine on there for my 98 2 weeks ago and it is great!