front pipe?

[encity5]

Sounds like this is a really noob question so my apologies ahead of replies. (i dont have any experience with car mechanics and tuning and such, still learning)

What exactly does the front pipe do? I understand that the exhaust gasses go through this pipe, but what are the differences between catted / catless / resonator?

I'm looking to install an aftermarket exhaust (invidia n1 or q300) and just want to make sure i do it properly. A lot of videos and examples i see always mention a catless front pipe.

So if im getting an aftermarket catback exhaust, do i need a new front pipe? what kind? any major benefits / pitfulls to having one?

Everything else mechanically is stock.
Thanks! any resources to understand these items would also be great! trying my best to learn.

[StormTrooper]

your car has two "cats" in the exhaust system. these are for emissions which i would assume are strict in new york.

the benefits to replacing the exhaust is to free up flow ( the header is more complicated than just bigger piping)

Getting just a catback will have little to no affect on power or mileage, it will make it sound different (usually louder and deeper tone)

Resonated will cancel out certain frequencies generally to avoid drone when switching to an aftermarket header.

[StormTrooper]

You should be able to search....try reading through the nameless/ jdl/ P&L header threads and the Perrin exhaust thread.

should have everything explained within those.

[mxsled]

This:

Axleback=Muffler
Catback = midpipe+muffler
Headerback= overpipe/frontpipe+midpipe+muffler

[encity5]

Originally Posted by mxsled

This:

Axleback=Muffler
Catback = midpipe+muffler
Headerback= overpipe/frontpipe+midpipe+muffler

yea i came across that diagram in my search, i know where the pipe goes.
Looking for more specifics about the roles it plays and the differences.

[jonbonazza]

It's function is really no difference than the rest of the exaust system -- to deliver exahust gases from the engine to the rear of the car where they can be safely vented to the atmosphere.

A resonated front pipe has a resonator which, like mentioned above, ultimately reduces drone and usually reduces sound level.

A catted front pipe will have a catalytic converter instead of a resonator for emissions purposes (This is what is installed from the factory).

A catless front pipe (A.K.A. a test pipe) has neither and is just a pipe.

[Cal3000]

Originally Posted by encity5

yea i came across that diagram in my search, i know where the pipe goes.
Looking for more specifics about the roles it plays and the differences.

The overpipe is basically there to couple the header to the front pipe. Overpipe geometry is important for performance of the engine and can be a vacuum to the exhaust gases that leave the header reducing back pressure.

The OEM front pipe holds the secondary cat for emission purposes. The secondary cat causes back pressure to the engine which restricts the breathing which restricts power. Your engine vacuums air through the intake and spits out exhaust. Exhaust pressure in the headers and overpipe will be higher with the cat than with no cat. You engine will be working against this pressure.
So when you remove the secondary cat, you engine can breath better and has less pressure to work against, so it increases the engine hp.

Midpipe and muffler allows the exhaust gases to travel from the car safely as jonbonazza said. Changing just these components will have minimal effects for performance increase.

Piping curving and dimensioning is also very important for performance through the exhaust system.

[j2digit]

Originally Posted by Cal3000

The overpipe is basically there to couple the header to the front pipe. Overpipe geometry is important for performance of the engine and can be a vacuum to the exhaust gases that leave the header reducing back pressure.

The OEM front pipe holds the secondary cat for emission purposes. The secondary cat causes back pressure to the engine which restricts the breathing which restricts power. Your engine vacuums air through the intake and spits out exhaust. Exhaust pressure in the headers and overpipe will be higher with the cat than with no cat. You engine will be working against this pressure.
So when you remove the secondary cat, you engine can breath better and has less pressure to work against, so it increases the engine hp.

Midpipe and muffler allows the exhaust gases to travel from the car safely as jonbonazza said. Changing just these components will have minimal effects for performance increase.

Piping curving and dimensioning is also very important for performance through the exhaust system.

My apologies as well for asking here , but is picking a catless pipe ,will it dramatically affect your emmision in the future? i know we won't need smog test for at least the next three years (here in cali) but just don't want to be on the illegal side of it.

thanks in advance

well, that was fast. I found this on the MXP website:
http://www.mxp-performance.com/?page_id=539

"the highway in the state of California or elsewhere that requires emission controlled to be retained"

so i guess catless pipe is a no no here in cali.

[Cal3000]

Originally Posted by j2digit

My apologies as well for asking here , but is picking a catless pipe ,will it dramatically affect your emmision in the future? i know we won't need smog test for at least the next three years (here in cali) but just don't want to be on the illegal side of it.

thanks in advance

well, that was fast. I found this on the MXP website:
http://www.mxp-performance.com/?page_id=539

"the highway in the state of California or elsewhere that requires emission controlled to be retained"

so i guess catless pipe is a no no here in cali.

With new cars, I think you don't have to get it smoged till after 6 years. I could be wrong.
You can delete your cats and just replace them when smog check comes around. Or just get a high flow cat if you are conscious about the environment.
I have a catless front pipe and will be getting a vortech SC. Will strip back to stock for smog check.

[swift996]

I just got a non-catted but resonated front pipe, it pulls smoother up top now. Probably good for about 3-4hp but who knows w/o a dyno. I'm running a header so I think the OEM front pipe was restricting the flow.

[infinite012]

Originally Posted by j2digit

My apologies as well for asking here , but is picking a catless pipe ,will it dramatically affect your emmision in the future? i know we won't need smog test for at least the next three years (here in cali) but just don't want to be on the illegal side of it.

thanks in advance

well, that was fast. I found this on the MXP website:
http://www.mxp-performance.com/?page_id=539

"the highway in the state of California or elsewhere that requires emission controlled to be retained"

so i guess catless pipe is a no no here in cali.

Removing your catalytic converter(s) completely is a federal offense. It is illegal to remove your catalytic converter(s) in all 50 states.

42 USC § 7522(a)(3)(A):
(a) Enumerated prohibitions
The following acts and the causing thereof are prohibited—

(3)
(A) for any person to remove or render inoperative any device or element of design installed on or in a motor vehicle or motor vehicle engine in compliance with regulations under this subchapter prior to its sale and delivery to the ultimate purchaser, or for any person knowingly to remove or render inoperative any such device or element of design after such sale and delivery to the ultimate purchaser;

[bkblitzed]

yea i dont think anyone cares about that law lol. I hear people going full catless headerback, but dont mention a tune, how are the afr's when not tuned?

[l0aded]

TL;DR in our car it does not nothing but changes the sound. / May be illegal to remove cats in certain states.