It's Christmas time (i.e. bonus check time), time for new toy.

Could someone please give me a quick education on the exhaust system, from the headers to the mufflers? Mainly as it concerns bolted mods on street drivable mustangs.

So, it goes.... headers, catalytic converters, pipes, mufflers?

I've heard talk of x-pipes and h-pipes as the mode for performance and sound. The muffers on the 05 are just a sound mod?

For education sake, please use Bassani as example.
http://www.rpmoutlet.com/05gtbas.htm

What are off-road pipes?
What are cat-backs?
When do exhaust changes become "illegal" for street use? What is drag race legal?

And most importantly, what kinda of changes will not pass a Texas State Emissions Test?

Thanks

 

You exhaust system has 2 headers, an h-pipe, and 2 mufflers.

-x/h-pipes and mufflers are both for performance and sound.
-in most states, changing mufflers and an h-pipe to a x-pipe is legal.
-an offroad x or h-pipe deletes the catalytic converters, which makes them not street legal.

 

On a stock mustang gt it goes headers-cat's-h-pipe- and the mufflers out back. The main difference between and h-pipe and and x-pipe is sound, there isn't too much of a performance difference. An h-pipe will give you a deeper- smoother sound and a x-pipe will give and higher pitched- raspy sound. When changing out the mid-pipe you can either get a catted mid pipe which means you get the x or h pipe with highflow cat's on it, or an off road pipe which means you get the h or x pipe without the cat's on it( this will pretty much double the sound of your exhaust) this is what I have and I love it. I am thinking about getting some high flow cat's being as it is a little loud sometimes. Offroad pipe are also illegal. You can also get a direct fit pipe which means it bolt's up to your stock cat's. This is what I started out with then put on offroad legs. That means I took of the stock cat's and put straight pipes in place of the stock cat's.

When doing a direct fit pipe it won't really make that much off a difference in performance or sound. You have to mess around with the cat's to really notice a difference. But this option also allows you to get the mid-pipe you want and later decide if you want some high-flow cat's on it or just take the cat's off.

I don't know too much about Texas laws but i'm pretty sure that offroad pipes are illegal there.

 

i laugh in the face of Emission test, for here in south texas all you need is some kind of muffler on the pipes and if not you show them a 50-state legal card like with the SLP loudmouths, when i had my old V6 i had open exhuast all the way back but cut a bullet muffler in half and welded it around pipe and it looked like i had a muffler but they never said anything about not having cats

 

your lucky

 

Wow, you got a C & L CAI, a tune, and no exhaust. Quick, with all the above knowledge just shared, go get a BORLA stinger cat back system, and make that puppy sing.

I know, a lot will say Corsa, Flowmasters, and what have you, but for the bang, and a very simple boltup, this system has been my choice in the past.

Would have thought you'd put exhaust before the CAI. Oh, and 2 1/2 will handle the hp just fine, don't waste your money on wider.

 

Oh yeah, forgot to add that..........................get borla!

 

i went Coffin exhuast on mine sound better then my friends Corsa's but i think the Borlas are good too

 

Thanks for the replys. I'll be adding a highflow cat and x pipe to my Christmas list.

 

i've heard both in person, and personally i prefer the sound of the JBA mufflers i have on my car to the borlas. they are plenty loud, esp when you get on them, but they aren't obnoxious - i never get dirty looks, only compliments and smiles.

the FULL JBA system is another story all together...that **** is loud.

kristina

 

does any one have a before and after dyno for high flow cats??

 

There's probably like maybe a 1-2hp difference, nothing to think about.

 

good choice...........bassani?

 

thats what I was thinking ... is it worth the cash and time to change them out?

 

I'm interested in getting some 5GTs/Stingers installed to see how it would sound, but not for $400. I remember when a pair of SS T-304 mufflers cost only $200 tops.

 

I'm still got a few more questions in me.

1) What's the layout with long tube headers? Can you have cats with long tubes? If so, will long tubes with cats pass emissions test?

2) What's the performance difference between shorty headers and long tube headers? Why weould you ever want shorty headers?

3) At what point is it a good idea to get a real custom tune (dyno style)? I have a C&L tune for my CAI. I'm going to be putting Steeda pullies in the coming week. I was thinking it wouldn't be a good idea to get a new tune untill I had add both pullies and x-pipe w/ cats. What do you think?

I won't be getting headers for over a year. FYI, I drag races for fun at my local strip pretty often on.

 

my pypes offroad H pipe gave me about 8 RWHP, not bad for $170 shipped. The stock cats are already high flow so don't bother changing them.

X-pipes generally give more power but I don't like how they sound.

Changing mufflers isn't going to give you much gains either, usually around 1-2.


To get the most power get longtube headers, offroad X pipe, and your choice of mufflers. That will give you around 20-25 rwhp gain. The longtubes are key, none of the aftermarket shorty headers give you any gains. Get the smaller sized ones if you don't plan on a power adder. If you plan on a power adder get the bigger one.

 

1) yes

2) read my previous post

3) neither pullies or exhaust changes require a tune