Because of $$$. Full system (done right) with headers is big bucks. With a full free-flowing system, you really need to invest in a good tune also, with less back pressure on the stock programming you will loose some low-end torque.

it can easily add up to $2500. Most don't want to invest that, so a cat-back (at 300-1000) is a good alternative.

If I was to get a full system, it would be from stainless works: Stainless Works Performance Headers & Exhausts

 

As I understand it on it on these boards, these engines are already factory tuned to breath as good as they are going to. That's why so many here advise against CAI's, K&N conversions and the expense of true duals.

IDK, there may be more to it than that.

 

with regard to the exhaust, a cat-back may be a better choice than a custom bent full length manifold-back exhaust, depending on the shop putting it together.

if you were to bend a full length exhaust out of 2.5" tube you would likely *reduce* flow capabilities and longevity as compared to the factory exhaust.

most exhaust shops do not use stainless tubing, so you will lose longevity for sure. also, most shops use a compression bender to form the pipe. this reduces the cross section of the pipe, usually by 0.5" so in the long run you end up with two 2" tail pipes that you have to replace every 3-5 years..... ask me how i know.

so, considering that you can get cat-back kits, pre-bent stainless, with increased size that is mandrel bent vs compression bent, that makes them superior to a custom bent exhaust (in most cases) and at a minimum equal to or better than the factory exhaust with regard to flow.

Robb's link above is the way to go if you are going to do a cat-back. there are a few others, but unless it is stainless i'd take a pass. And then, do it for sound, not for performance. the factory setup is not as restrictive as the aftermarket wants you to believe. backpressure costs power and fuel mileage, and the auto makers know this too, so they flow as well as drive-by noise requirements (and NVH engineers) will allow. there just isnt that much to gain in the aftermarket in the power department from the converters back.

stainless works also sells headers, which is the way to go for performance. BUT ... it's pay to play ... and as mentioned above, they will only be optimized with a tune.

FWIW, a full setup from stainless works will cost you about $2600.... BUT, it is probably the best you can get. a cat back setup is about half that much.

 

^^ Had the same experience with all of my old body Fords. You would have expected that I learned after the first failure.... The shop was good about fixing it, but aluminized steel is crap, especially in snow country. T-304 stainless is the way to go. (NOTE, T-409 is lower grade than T-304 for those not aware).



Also, reps sent great post

CORRECTION: A magnet will stick to 400 series stainless, where as the iron content is low enough in a 300 series it will not stick

 

www.stainlessworks.net Best Exhaust Period!

 

Thanks to all that responded, I will definitely use this info to help me decide what I to do next.

 

Just a little clarification, all stainless steel, and all steel, contains iron. That's not a bad thing.

 

Yup, should done better research . What I should have said is the Iron content in 300 series stainless is low enough (66-75%) that is most cases a magnet will not stick to it, where as it will to 400 series making it easier to differentiate the two.

Good catch, thanks. reps sent

 

i would also add that factory exhaust is typically 400 series stainless.

Some might disagree, but IMO, if you are buying an aftermarket kit that is 400 series stainless, it will be at least as good as the factory exhaust, and to me that would be acceptable.

if, however, you live in an enviroment where factory exhausts do not last as long as you would like, then you should opt for the 300 series stainless if you are going to buy a kit .... and if that's the case you should RUN away from aluminized, as it will not perform well for you at all.

 

I have not been on the forums since last spring when I left the city for the Lake. I just got back from hunting and will be leaving again this weekend I have the Stainless Works exhaust and a 5 Star Tune in my 2010 5.4 and I can not believe the difference. There is no compasrison to stock at all. The exhaust starts with ceramic coated headers and a true dual exhaust with hi flow cats. Everything is mandral bent and it flows. For the tune I went with a straight performance tune. I now get as good or better gas milage than I got before with the stock setup. The tune also tunes up the transmission which was a slush box before - lots of slippage and slippage is friction and a loss of power. I have put on probably 8- 10 000 kms and when you put your foot down the vehicle responds right away.

 

You will find a lot of this here, not too many guys like Flowmaster. I do, however. Maybe for my next muffler I will look into them but for now I like my FM.

 

I have always been a fan of flowmaster as well. Right balance of sound for me but in the end its all preference.

 

There are a lot of good exhaust systems out there on the market for the F-150 except the majority of them produce that annoying drone at highway speeds. If you want to avoid this look into a Corsa system. They have done a tremendous amount of R & D to prevent this problem