2005 Legacy 2.5GTL Exhaust

[RiceKiller2.5GTL]

I am purchasing a 05 Legacy 2.5GTL sedan that I testdrove today. I love the car, but the exhaust is way too quiet for my taste (currently own 94 trans am and 71 nova LOL). So i was wondering what the loudest and badest exhaust system available for the 2005 Legacy 2.5GTL Sedan?? Also, what are the functions of down/up pipes?

[BatChips107]

there is a massive amount of sound clips and aftermarket exhaust for the car now.. do a lil SearcH on the forum... for quick reference... uppipe mod is to remove 1st cat and give quick spool (very encouraged mod to accompany future upgrades).. adding a downpipe alone to an engine reflash/management is what we call "stage 2" (more hp and torque)

[RiceKiller2.5GTL]

well I live in NJ so about removing Cats....yea NJ SUCKS! i dont know the regulations exactly, but they are strict...i guess a catback would be better then huh?

[BatChips107]

catback is good just for sound... it doesnt really give you any performance gains... that is where the up/down pipes come in... removing the cats is what free's up HP/TQ... but congrats with the car.. goodluck

[godwhomismike]

remove the cats and the cans and you got a sweet loud ride

[red beast]

it's not how loud it is, it's how fast it is.

 

sleepersarebetter.

[RiceKiller2.5GTL]

thanks! so you are basically saying that if i went with say the Borla cat back and left everything else stock vs. if i bought the borla catback and bought catless up/dp they would sound similar but the catless would give better performance? also, do you think catless up/dp would pass NJ inspection?

[axis008]

Moved to turbo powertrains section. Good luck with your search!

[Xenonk]

I am purchasing a 05 Legacy 2.5GTL sedan that I testdrove today. I love the car, but the exhaust is way too quiet for my taste (currently own 94 trans am and 71 nova LOL). So i was wondering what the loudest and badest exhaust system available for the 2005 Legacy 2.5GTL Sedan?? Also, what are the functions of down/up pipes?

 

If you want loud, get custom straight piping.. this is the following that you need:

 

4" down pipe

3.5" midpipe with no resonator or cat

3" y-pipe

3" straight pipes as "mufflers"

 

That is just plain loud. You should hit 115+ dB with this setup. There is no current turboback exhuast for this company, but you can definitely stop by an exhuast shop to custom make one (as many people already did).

 

Function of the following:

 

Uppipe:

creates a "better" (efficient) spool to the turbo from the HEADER (note to all, it's not HEADERS unless you run a V-type motor or have a multiple piece exhuast manifold). The stock uppipe as a cat, so by freeing up the cat and getting a catless uppipe, this will aid in better spool and a faster response to get the turbo to build boost quickly and minimizing the lag.

 

Downpipe:

Once you have all that exhaust gas going into the turbo, it has to come out somewhere. The stock downpipe has a very poor design, namely a bad and very restrictive flange plate that pretty much blocks up the exiting exhaust gases from the internal wastegate (it's like putting your finger over the whistling tea kettle, building up all that pressure and nowhere to go). Most aftermarket downpipes are larger and some even deletes the stock 3rd cat allowing better flow.. the better the flow, the more efficient the turbo works.

 

If you can imagine all of this in a form of a water wheel, then it's easy to understand, water goes in, water has to come out.. you funnel the water (think of header and uppipe) from 4 different rivers (cylinders, if you see the analogy) first to create speed for the water to spin the waterwheel (turbine), once you spin, you have a lot of water built up (pressure) spinning the wheel, the water has to exit out to a pond or a larger river (down pipe) that can handle the amount of water.. or you will overflow the pond or river and that can cause trouble (exhaust leak from excessive pressure or blowing out the pipes in the exhuast at the worse case scenario)..

 

It's all the same with car designs as to nature.

 

 

Keefe

[Xenonk]

thanks! so you are basically saying that if i went with say the Borla cat back and left everything else stock vs. if i bought the borla catback and bought catless up/dp they would sound similar but the catless would give better performance? also, do you think catless up/dp would pass NJ inspection?

 

things will definitely sound all different.. the metal resonating from each pipe will give it a unique tone, this also includes how thick the walls of the pipes are and the size of the piping that is creating the sound.

 

Catless will give you a more efficient exhaust flow, but your ECU will think differently and might think there is something wrong with the car and make it go into reserve mode and give you a Check Engine Light (or CEL as we all know it).

 

I am not sure if it will pass NJ inspection because I dont live in NJ, so you will have to find that out yourself or from other NJ residence on what NJ uses to test emissions to find out if you can fool the EPA that have a legal car, but if you get caught, you better get ready to be fined as much as $250,000 and/or jail time for it.

 

Keefe