Hey guys,
I want to get more air in and out of my 5.4. I am thinking it will be best to go with K&N air intake and then cat-back dual exhaust. My problem is that this is the first 5.4 I've ever owned and I am having a hard time finding specifics on the right size of exhaust/ muffler etc. Any suggestions? Also, despite my user name, I now own a f250 so it's a bit different than the f150 exhaust (I'm pretty sure).

 

What year is your truck?

 

99-04 the Y-pipe is probably the biggest restriction, so that's probably the best place to start. The 05+ exhaust is pretty good the way it is stock.

In either case, the stock intake and filter provide far more air flow than the engine can consume even at WOT, so the K&N won't really do anything but lighten your wallet.

 

On my 08 w k and n and dual flowmaster catback I got .3 or .4 MPG from the two so u tell me if that's worth it or not.

 

i second don't get the K&N intake, the stock system is far more superior for filtering dirt, and it flows more then the motor will ever need. The only thing the K&N does is lighten your wallet and gives you this roar when you stomp on it. But i like the roar so i keep mine

 

It's a 2002.

 

my '99 had 3" pipe from the factory, so i thought it would be silly to replace it. so i just had a magnaflow cat and muffler welded in place of the stock units, with a nice 4" stainless magnaflow tip on the end.

i ran an outlaw intake, and thought it was a good product. none of the above mods were magical performance or mileage-wise, but it sounded nice.

 

I believe the 5.4 and 6.8 intakes and exhausts are the same.
And I have yet to see any objective evidence that aftermarket produces any significant improvement on a stock 5.4. Only marketing "claims", the biased opinions/wishes of people that paid big $$$$, or when compared to a filthy stock filter. Maybe a scosche more power on a 6.8. They make more noise, but not more power.
Unlike many trucks out there, the stock parts can flow more than stock engine needs already. Whether that is good or bad depends on your desire to spend money.

On the other hand a custom tune is worth the dollars. Not a "canned" tuner, but a really good one. Mike at 5 Star is a great source.
And a Y pipe should help a bit. Being inexpensive, I'd say it is worth the dollars.

And of course, a supercharger changes everything!!!!

 

You mentioned the Y pipe. That has been eating at me for a few weeks now too. I noticed the sudden reduction in size of the exhaust right at the "Y". The only explanation I can think of that the quick reduction makes the exhaust gases flow faster. It just seems logical to me that taking that restriction out would only help with flow. Is that the main goal behind a Y pipe?

 

I get a kick out of the people who bash the cold air intake. It will improve your gas mileage on the 2 valve, the 3 valve is just a better motor. Most of the people who bash the cold air intake never even had one. I'm not going to say it will give you more horsepower, because I didn't do a before and after test for that, but I got one more mile per gallon after I installed mine. At that time my truck was all stock, and that was the first mod I did. I can't comment on the exhaust either, my exhaust project is still on the back burner. Good luck.

 

I had the 2V 5.4L in an F-150 that I put a cheap CAI system on and I def noticed a difference in its responsiveness. I also noticed about 1 mpg increase on highway driving... And I put 50k a year on that truck hauling commercial piping to job sites. I recently put the K&N CAI on my 3V 5.4L F-250 and it seems to get maybe .5mpg better but the biggest difference on it was the responsiveness of the throttle. The engine seems more alive with it. Hopefully it gets even better when I get my tuner on it from Mike at 5-star!

 

If you want CAI, then K&N is about the only deal in town for the 5.4. NO ONE makes anything for these engines in this chassis. I took a peek at the stock airbox and thought I saw an air intake silencer where it mounts into the fender area. My 07 Expy had one in the airbox and that got yanked. If it is in there on my 250, it's coming out too. I can't say anything as to any MPG increase, but it certainly made my Expy sound better under throttle with it removed.

Your best bang-for-the-buck is going to be the custom tune from someone like Mike at 5 star. I haven't heard a bad thing about that setup yet. I'm hoping to head that route later this summer if funds allow....

 

Well, alright! IAC died today. At least that's what the Ford service dept. told me. Wanted to charge me $190+ to fix the problem. No says I. $41.99 at Advanced auto and a half hour fix. They aint gonna get me like they did last week. $216 to change two COP's and a plug. I shouldn't have let those COP's scare me. From now on I'm doing it myself. I can't afford to be hosed every time my sweetheart......ahem......I mean my truck decides to blow a censor. Honestly, I think I've been pampering her too much. She gets put in the spa at least twice a month. My dog doesn't even get that kinda treatment.
So yeah, thanks for the great advice yall. I think I'm gonna save up and go with a Bully Dog tuner from Summit for $399. I'm hearing the most positive things about that for performance and mpg improvements.

 

Bully dog is a canned generic tuner. Think of it as a one size fits all aproach to tuning. By using strategy specific tuning you will get the best bang for the buck. 5star is highly recommended or look at the gryphoon tuner based on the edge platform with custom tunes. Either way a step ahead of the bullydog tuner. Also as far as air filters I would steer you away from a oiled filter as the dry filters are better overall and will save you the potential of maf issues due to a over oiled filter.