Borla Mufflers.... which one...

[SweeT93]

I have the full borla cat-back on the car now... along with a nice set of headers, but I was thinking about changing the muffler... maybe one of those borla race mufflers... just wondering if anyone has any other borla muffler on their car and what kinda performance/sound it produces...

[knb13]

just for my curiosity- whats wrong with the muffler that comes with the catback?

[SweeT93]

nothing at all, just wondering if a different one would give a little more power

[knb13]

no it won't...and a muffler won't change performance, just sound.

[proboner]

yes a new muffler will give you more power, especially going from a chambered borla to a straight thru. however it wont give you much power, so changing out the muffler for just that reason probably isnt the best idea. if your really looking for power you should sell the borla catback entirely and go with bigger diameter piping and a straight thru muffler.

[ouch1011]

Borla does not make a chambered muffler. All of them are straight, including the one on their catback systems.

Switching from any muffler to any other muffler will not net you any power unless the muffler you are switching from is clogged.

[SweeT93]

anymore then 2.5"pipe isnt really making any difference, but i was thinking about changing the muffler...not sure if im going to but it was a thought... after i finish the interior work though

[proboner]

borla doesnt have 2.5" piping, the ID is actually closer to 2". the borla muffler isnt chambered? its quiet enough to be a chambered muffler, well whatever it is, its gotta be restrictive if its that quiet. also, how do you figure switching from any muffler to any other wont net you a gain. what about switching from stock to a straight thru, thatll gain you power for sure.

[knb13]

yes the Borla is a straight through....and the pipe is large enough for your N/A aplications. Its the small size (among other things) that gives it the amazing sound.

Going from a stock muffler to a straight through muffler MAY give you 2.2693hp but nothing you'll feel- i wouldn't even really consider it a gain unless you feel the need to tell people your now making 166hp. :shrug:

Most catbacks don't even give you enough to feel- it isn't until you add more breathing mods that the benefits of the exhaust are gained. If its between a stock muffler with mandrel bent pipes or aftermarket muffler with stock pipes- i'll take the mandrel bent/stock muffler combo. I just don't consider a muffler to be a performance mod but more of a sound changing mod.

[ouch1011]

Quiet doesn't mean restrictive. It can just mean well built, and in the case of Borla, I'd say thats true... :shrug:

[proboner]

ok, well all im saying is that if your looking for more power youll probably want to upgrade your whole exhaust. what i would do is just get something that has 2.5" mandrel bent piping, whatever muffler you like, and an exhaust cutout for when you need the power.

[knb13]

you only need a cutout if your boosting...the loss of back pressure on our engines in N/A form isn't a good thing.

[proboner]

if you put the cutout right before your muffler you wont have a loss of power

[pgtfreak]

1. Borla is not Chambered. None of their mufflers are.

2. It's quiet because of it's size, and it's awesome resonator.

3. Switching to a different muffler will not net ANY performance over the muffler already on the catback. Straight-through is straight-through. Hell you can cut off the muffler completely and won't see any increase in power.

4. Borla is 2" outter diameter http://home.comcast.net/~jankypgt/borlasize.jpg that size is perfectly fine for an N/A 2.5L.

5. 2.25" ID is the best diameter for a 2.5L engine. 2.5" won't hurt anything, and will give a slightly larger peak hp gain that a borla, but the borla will out perform it thanks to it's consistant gain, through-out the power band (don't focus on peak power). I don't know about everyone else, but I'll take a system that delivers 5hp increase through-out the power band over a system that gives a loss in the low-end, evens back to stock in the mid-range, then delivers a 5hp peak increase in the high-end.

6. All of these things have been covered, in-depth, many times.

7. Since this is not a performance topic (as I have said, changing will not net a power gain), and because this is pretty much only going to be answered in opinions, please search for different sound clips, and choose a style of muffler you enjoy the look of. Because that's pretty much all it's going to boil down to; a different look.

[SweeT93]

I actually measured the piping today... the inside diameter is approx 2.37" outside is 2.5" , now being none of the borla mufflers are chambered will that make any difference if i decide to supercharge or turbo the car later on? Should i look into a chambered muffler if i decide to boost?

also what are the advantages to a chambered over a non-chambered muffler other then noise levels?

[proboner]

well if 2" piping is fine for a pgt, and if replacing a muffler wont gain you any power, they why does anyone ever upgrade from stock?

if your planning on super/turbo charging then its definately a good i dea to upgrade from the borla... i guarantee itll be a restriction.

[mvaughn1]

Dude, you have a really nice exhaust that works better than most....just keep it and spend your money on a new IM or pulley or strut bars or something.

Mike

[mvaughn1]

well if 2" piping is fine for a pgt, and if replacing a muffler wont gain you any power, they why does anyone ever upgrade from stock?

i hope this is an argumentative question cause otherwise it's really dumb....

[ouch1011]

well if 2" piping is fine for a pgt, and if replacing a muffler wont gain you any power, they why does anyone ever upgrade from stock?

Because most people are convinced that bigger is always better. :shrug:

Generally speaking, the best size catback to run is going to depend on the exhaust manifolds/headers. Whatever the smallest diameter the tubing is after the two banks of exhaust have come together should be what you run for your catback, since the smallest diameter of your entire exhaust system is essentially going to limit your exhaust flow to whatever can flow through that smallest part. What is the point of running a 2.5" catback when the collector on the headers is only 2"? I believe the stock manifolds and most aftermarket headers run into a 2" collector. Pacesetters I believe are the only ones that are different, since they run into a 2.5" OD collector (about 2 3/8" ID). I run Pacesetter headers, with a modified Pacesetter catback (different resonator and Borla muffler), which is also 2.5" OD. :shrug:

Please let me know if that didn't make sence, and I will try and rephrase it.

[knb13]

i wanted the Borla for the sound more than anything.

It will work with boosted aplications, its just not ideal. This is where your cutout would come in handy my friend.

[Grand Tourismo]

ok stop the shit. lets clear this up. justin you know your not changing the exhaust, for one get the interior done in that bad girl. that eclips sub you got is nuts for just 1 i'd work from there. screw the exhaust.
And as far as the sound from the BORLA it has a lot to do with the resinator that is on the cat back, wich, Wich is manderl bent. just because she sound's quiet does not mean she's a Pussy, infact when a testpipe is added the car sounds nuts at WOT. a chamberd exhaust is restrictive, just think about it there are fold's and shit the exhaust gassses have to flow through before they exit, and come on you should know this owning a first gen. turbo's need bigger exhaust, because you ramming the air down the engine throat.

[proboner]

well if 2" piping is fine for a pgt, and if replacing a muffler wont gain you any power, they why does anyone ever upgrade from stock?


ok for those of you who didnt get it, that was sarcasm... also, just because the collector is 2" doesnt mean that you wont benefit from a 2.5" exhaust after that. the best exhaust design is one that slowly increases in diameter as it moves towards the back of the car. anyways lets get back on topic and stop arguing with eachother.

IMO, changing out your borla muffler for another one in order to gain power is not worth it. if you actually are planning on going forced induction then it probably will be worth it to go with a different setup.

[pgtfreak]

ok for those of you who didnt get it, that was sarcasm... also, just because the collector is 2" doesnt mean that you wont benefit from a 2.5" exhaust after that. the best exhaust design is one that slowly increases in diameter as it moves towards the back of the car.


No, the best exhaust is one of constant size, with as few bends as possible. Going small-larger will slow down the exhaust's velocity and will cause turbulance, which in turn will cause backpressure. This is [in a nut shell] why the borla piping, and nothing larger than 2.25", is perfect for this engine. It simply doesn't produce enough exhaust [in N/A form] to take advantage of piping over 2.25"

And people upgrade for mandrel bends and straight-through mufflers (well, honestly, most upgrade because they are under a false understanding that larger piping is going to yield huge performance on their tiny 2.5L N/A engine).

I actually measured the piping today... the inside diameter is approx 2.37" outside is 2.5" , now being none of the borla mufflers are chambered will that make any difference if i decide to supercharge or turbo the car later on? Should i look into a chambered muffler if i decide to boost?

also what are the advantages to a chambered over a non-chambered muffler other then noise levels?


If you measured the piping on your catback and came out with those measurements, you don't have a Borla catback (I posted a picture of me measuring a Borla, and it's 2.0" Outter diameter). Or are you talking about the muffler tips?
There are no other advanatges for a chambered over straight-through. Chambered mufflers will create more backpressure, so no you shouldn't switch to one.


I re-opened this thread for you, because you said you had a valid question that you needed answered, but so far, this thread is just another muffler topic :eh:

There are over a hundred topics in the 2.5 performance forum dealing with mufflers. Just because they may not be Borla mufflers, doesn't mean they aren't relevant.

[Grand Tourismo]

Is it not true thow that BORLA changed the diameter of the piping. I have seen 2 types of BORLA's one with the name on the side and other with nothing both are identical, but i belive the older 1's have a lager diameter, like justin said a 2.5. in all honest I measured mine my self and it was just a hair shy of 2.25

[pgtfreak]

Is it not true thow that BORLA changed the diameter of the piping. I have seen 2 types of BORLA's one with the name on the side and other with nothing both are identical, but i belive the older 1's have a lager diameter, like justin said a 2.5. in all honest I measured mine my self and it was just a hair shy of 2.25


Well, the theory is the older borlas measured 2.25" Outter. While everyone who has gotten a brand new one in the last few years, have measured and came out with 2.0" outter (though my Borla is about 3 years old, and people even 2 years ago were saying their borla was 2.25"). I really don't see them [Borla] one day waking up and deciding, "Hey, lets shrink down one of our best selling exhausts"! (Borlas use to sell for $200 shipped)
Borla has NEVER been measured at 2.5" Inner or outter.

I guess if you want a real answer, calling up Borla would be the best way of going about it.

But FWIW, every Borla I have seen measured, has been 2.0" outter diameter, 1 7/8" inner. I have never seen anyone post proof showing that their Borla is 2.25", or otherwise. While I and others have posted our proof that it is in fact 2.0" outter.

[SweeT93]

ok, so what im thinking is that for now nothing needs to be done, BUT if i decide to boost then changing out the muffler would definitely be a good idea..
I was thinking in the next year or so to possibly boost, so at that point i will look into the best muffler to run... although i really love the way my borla has performed and will probably stick with another borla. Thanks for all the input.

[pgtfreak]

Honestly, if you're already sporting 2.5" piping, with a straight through muffler, nothing will need to be altered for boosting.