So, who's done this, and how do you do it?

I'm just building the exhaust in the next week for my 10AE.. I want to make it as quiet as possible, stock-quiet if possible even. I've got some stuff laying around that may or may not help: a 3" Thermal R&D Muffler (suppossed to be quiet) and some old Apexi presilencers pirated from an apexi 3" catback for a DSM.

I just want to build a single exhaust because it looks easier and cheaper, I ran out of money buying the turbo, fmic, ems, engine and etc lol

Are there any tricks to doing this or do I just have to get lucky? Who's got the quietest mufflers that are still very very free flowing? Car will hopefully be making 400+whp...

 

Quiter=More restrictive.

It's a trade off you give up some flow for the comfort of quiteness. If you want it quieter as stock you will have to use small piping and a couple presilencers and a large muffler. Usually the larger diameter of the muffler (not the tip) has more sound suppression.

I doubt with single muffler and a halfbridge you will get it stock quiet.

 

well I am not using small piping! I want it to flow like a straight-through but hopefully have less noise than it had last year.. no fun having a fast car if you're afraid to use the go-pedal because everyone wtihin 5 blocks will hear it...

 

its funny cuz i know how that feels!

 

Use a different style muffler.

 

Not always. A restrictive exhaust is usually a quiet one, but a quiet exhaust doesn't have to be restrictive. It'll cost you though...

The most obvious thing is to throw out the idea of a single rear muffler. Doing that would be really silly you want quiet. Each muffler only deals with half the sound energy and hence is more effective. Size the pipes properly and it'll flow as well as a single.

Use mufflers with big cans! It seems really obvious, but for a given pipe size (say 2.5") a muffler with a bigger can (and hence more sound absorbing material) will be quieter than some silly little N1-style muffler. Look at the size of the mufflers on the Racing Beat and HKS Super Drager exhausts as examples.

Stick the longest resonator you can fit the centre, preferably oval for the same reasons. You can also stick short round resonators in the pipes between the Y and the mufflers for a little more effect.

Both the resonator(s) and mufflers can be straight-through (or offset) for maximum flow, and still supress sound well. Most of the quality Japanese aftermarket stuff proves this.

Another option is a butterfly valve in the exhasut (like a throttle) that is closed at low load for maximum noise suppression and opens under load for maximum flow. These aren't cheap though, especially if you get one with a decent control system.

To rehash a simple rule, you have three design choices:

- Low restriction
- Low noise
- Low cost

Pick any two...

 

Silencers...

 

Open downpipe and earplugs..... Best of both worlds!

 

Im running a resinator for my midpipe and believe it or not the tips I bought have built in resinators too. I was amazed with the differance when installing the tips due to the BMagic I have on my car. Had to extend the tips for the rear skirt.

 

You mean restrictive butt plugs? Hell no...

 

don't use a silenser, or a pre cat or any of that other BS.

All you need is a borla xr-1 oval or magnaflow SS straight through exhaust welded in where your cat used to be ( see pic below). This will deepen the tone which in turn quiet the exhaust down. Bonus: It also does not restric flow so you will gain all the ponies you would have lost by using that other crap people listed above and its made of 304 SS so its not going to burn out on you.

Double bonus: They are only about a 100 bucks at www.jegs.com

 

You've got 2 good pre-silencers - put them both in, one after the other in series, in the cat space.
Then put the muffler at the end.

It will purrrr like a kitten.

The only down side - you will hear every rattle, clunk, buzz & squeek in the car.

 

SHIIIIIIIIIIIIIIIIIIIIIIIIIIIT
i had this long *** reply written out. POS! lol

If you run a presilencer. Full 3", and a fairly quiet but can be good flowing and 3" and all of that catback. Or if single maybe try a extra presilencer inbetween the presilencer and the muffler. I personally have an idea I stole from some porsches.

Alright, this is the same presilencer that racingbeat uses in their turbo back. $94
http://www.racingbeat.com/resultset....rtNumber=16434
Theres a slightly smaller version of it too

However on J-Rats car, he has 3" dp/mp straight through w/ the RB turboback catback only. And it was aggressive, but not overly loud at all.

 

never heard of doing 2 mufflers replacing both cats like that. neat idea
-Ben

 

the Thermal R&D (www.thermalrd.com) muffler was like $250 US when the previous owner paid for it, it's a BIG straight-through can and should be pretty quiet..

I really like that RB presilencer

I guess I should use the presilencers I've got then, and that muffler!


thanks everyone

 

that RB presilencer will restrict your exhaust flow and do jack **** for quieting down your system. I have already bought all this crap trying to quiet mine down and nothing works better than a free flow v8 style exhaust in the center.

 

Make the downpipe as thick as practical. Use SCH40 weld els and pipe from a plumbing store instead of fancy stainless bends. The thick pipe really absorbs the sound and will only be a little heavier then a much thinner pipe.

 

I would suggest buying a pre-muffler/silencer with stainless steel packing in it. the cheap fiber packed ones tend to blow out and get louder much sooner then a high quality stainless steel packed one's. As far as the muffler at the end of the system, get the biggest...longest case you can to fit. It isn't as important to have a stainless packed muffler(s)at the end of the system as the temps have dropped quit a bit by then, unless of course you like to shoot flames.


I am running two of these mid pipe http://www.jegs.com/webapp/wcs/store...tegoryId=20853 and a RsR fart can at the end.

It is not super loud, but has an excessive reverberation at cruising speed. I think it is louder inside the car then outside. People tell me it sounds great, but I think it’s a little loud. So I am going to replace the fart can at the end with a BIG fat oval muffler. My system is 3” single turbo back

 

I've got a Rotaflo from Aus. on the way and I'll let you know how much it quiets down an N/A streetport when it gets here. These are supposed to quiet the **** out of ported rotaries and flow mad hp. The cans are a little over 8" in diameter with lots of packing. Inlets are 2.5 - 3.5".

Currently I've got 2 4" round magnaflows for presilencers and a Thermal R&D out the back. The Thermal is 3 years old and blown....the wierd thing is the magnaflows make a metallic tink noise instead of a packed thunk after they've been on the car for less than a year. I'm worried those have blown already! Anyone had experience with blowing out magnaflows?

 

the thermal R&D's have lifetime warrantys I thought! that's what they told me when I bought it.

 

i have a huge magnaflow where the main cat used to be. single 3" in and dual 2.5" outlets. i have a dynomax ultraflo bullet muffler at each corner. those are actually kind of small and didn't do much. i like the tone, it's just slightly louder than i would like. and it resonates in the car after the twin scroll opens. if the twin scroll is closed, it's nice a quiet.

 

You need an OFFSET, straight through muffler.
This is the type of a perforated tube that's offset from one end to another.

All those other straight-throughs that run straight hardly do anything to quiet the exhaust down unless you tinker with "exhaust tuning".
The problem with this type of exhaust is that the exhaust might be quiet at one range of RPM's, but it gets loud at other RPM's.
The Racing Beat exhaust systems are notorious for this - at 3kRPM, the exhaust gets noticably more loud!

Borla, Magnaflow, and Dynomax makes their versions.


-Ted

 

yea well dynomax exhaust get loud over 3500 rpms, thats why I ended up put a few resinators on. Worked alittle bit, not as bad.

 

what about this muffler? http://www.jegs.com/webapp/wcs/store...tegoryId=10265

specificly the 3" in/out one thats 36" long (yes.. 3 foot muffler)

 

It would be nice, except...it doesn't fit under the car.

Either you need to jack the ride height up, or run a smaller driveshaft...

There is just no way something like that (6" diameter?) will fit underneath.


-Ted