Exhausts noise...3" much louder than 2.25"?

[George]

Hi All,

Just curious for those that know, but is a 3" exhaust much louder than a 2.5" ?

Does it depend on the manufacturer or muffler or ??

Cheers,

--George

[DlandryTSI]

Its all based on what kind of muffler and if you have a cat. My car has a test pipe with a dynomax muffler. Its fairly loud but tolerable.

--Dave

[BoostedGS]

I agree with Dave here. Piping size probably plays a little part, but it's mostly the type of muffler and whether or not you have a cat.

I have 2 1/4" piping turbo to tip with a Naxos muffler and a testpipe, Art has 3" piping turbo to tip with an Extreme muffler and a testpipe. His car is louder than mine, but it's mostly because of his muffler....makes his car sound kinda like a V8! I'm not clowning him though because I'm about to buy his exhaust! :D

Patrick

BoostedGS - finally back on the road and boosting!!

[George]

thanks guys!

So if the muffler is a big factor in the noise, does it also affect the efficiency of the exhaust system? That is, does a 'quiter' muffler restrict air-flow more? or enough to offset any gains by changing the exhaust?

Cheers,

--George

[DlandryTSI]

If you ever goto an exhaust shop and look at some of the mufflers that they have on display, you don't want the ones that have a Z type of flow. Ideal mufflers are the ones with a solid 3" straight through. Anything smaller is more of a restriction.

--Dave

[hoffman]

make sure it is a straight through muffler. anything else is just going to be useless on your car. you don't "have" to get a high-flow cat. the other 2 options are a "race cat"(which i'm pretty sure is nothing more than a resonator) or a test pipe. when i went from stock to a 3" turbo back, man, the turbo spooled so fast.:D if you setup your exhaust right the first time, you can just swap the cat in and out when it comes time for emissions. the only noticable difference is the smell. but i've driven past plenty of cops and as long as you don't have it floored, they'll never know.


and mine sounds more like a rally car(tommi edition evo VII, baby)

[George]

cool...definitely sounds like there are more options than I originally thought. I'll have to hit an exhaust shop and take a peek.

thanks alot for the info everybody!

Dave, would you mind moving this thread over to the appropriate forum when you do the cleanup?

And thanks for creating the extra performance forum(s) so quickly!!!!! :cool:

[DlandryTSI]

Sweet it actually moved w/o any problems :)

--Dave

[GSXMonster]

3" Turbo to tip, testpipe, and a small, oval, straight through A.T.R. muffler... LOUD... Especially when decelerating around 4000 RPMS... Guaranteed to set off any car alarm I drive past. :)

One option that wasnt mentioned was that you can get a 3" or 2.5" resonator put inline with the exhaust piping, if noise is an issue. As long as it is straight through like the muffler, there shouldnt be much of a decrease in flow.
Rob

[hoffman]

when you go into a shop, stay away(far away) from anything Flowmaster. they basically suck. RRE has the Apexi N-1 cat-back for $4??. it comes with an adapter to bolt up to the stock DP and cat. you WILL feel an improvement. then later on you could buy the N-1 DP. this will replace the DP and cat. you can use this on the days you feel like hitting the track.

i plan on going with this setup. i'll just bolt up the stock DP and cat when ever i need emissions done.:D

that should come out to around $800 for a 3" turbo back. and there is no reason to pay someone else to do something as easy as putting in an exhaust.

ask Rob how much the A.T.R. is.:p

[George]

thanks for the info everyone!

Just gotta save up the $490 now!

Rob, I haven't heard this option mentioned before...anything special with these? Would I have to buy a system that takes this into account or cut up something to accomodate?

oh...and how much does the A.T.R cost? :D


--George

[hoffman]

all a resonator is, is a long thin inline muffler(in a sense). it just reduces some of the exhaust noise. which in my opinion is another restriction.