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Choosing The Right Muffler
How to get the sound and performance you desire.

If you’re running on the street--or in many racing series--you need mufflers. They also come in handy during long drives, when the drone of the exhaust can be downright exhausting.

But which muffler should you choose? It depends on your taste, your engine, the space available on your vehicle and how you use that vehicle, too.

After all, a muffler can be used to tune your engine’s powerband, so that it makes more peak power (a good goal if you’re drag racing or hitting the Autobahn) or more midrange torque (preferable if you’re road racing or driving on the street). By its nature, a muffler also will have a profound impact on the way your vehicle sounds. Often, you can find several mufflers that provide comparable performance for your application, but one is quiet, one’s loud and another is somewhere in between. Hi-po mufflers offer some other advantages over stock units, too. For starters, most hi-po models will last considerably longer. Some even come with a lifetime or million-mile warranty. Performance mufflers also can improve your vehicle’s fuel economy by helping the engine become more efficient. And because some mufflers come with exhaust tips already attached, a simple swap can make a styling statement, too.

* Muffler Designs
A muffler’s purpose is, quite simply, to muffle the noise produced by the engine. When it comes to high-performance mufflers, there are essentially three designs: cancellation, absorption and diffusion.

A cancellation muffler features chambers inside, which tune and cancel various sound frequencies.


In an absorption muffler, the exhaust passes through a perforated tube that’s wrapped in sound-deadening material. Various kinds of packing material are used to absorb sound, including fiberglass (hence the term “glasspackâ€

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The Speed Lifestyle magazine in the Islands, ZORCE

gr8 post!

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Drawers : noun \ˈdraws\
A piece of clothing: Not a Shark

Oh gawd here we go again, trying to confuse somebody else head now.
Thas why I hate these articles, its best to just know the physics of the whole shebang

damn yeo
really good info there

Good read, shows that putting any old fancy bling fart can won't neccessarily make an improvement.

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Taking economy cars beyond their limits

Mr. Minister strikes again.....sweet info bro!

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Trying to be the very best that I can be!! Supernaturally.

Sober since 9/12/2010

Teana JK stuff For Sale

gr8 info dude!

good infor..

Well Packaged information man.

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"Look down at me and you'll see a fool. Look up at me and you'll see your god. Look straight at me and you'll see yourself." - Charles Manson

Sweet read dude!

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"Happiness lies in conquering one's enemies... in savoring their despair, in outraging their wives and daughters.

- Genghis Khan
[sms]

greatly appreciate the info...i'm going to modify my muffler/piping simple based on what i was told...but now i know exactly why and what to expect...

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Back 2 my 1st love... NISSAN...



NISSAN... or walk...

Great info pallie.

We have one of the old time barrels on meh dad's car, "thrush barrel" i think it's called ....sounds irritating at times but with a straight pipe before it ....sounds wicked...especially at high RPM's when shifting gears

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"God's Greatest Creation: THE ROTARY ENGINE!"

well done

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"2Pac."

cool

Very good article

I have a question doh, What is a better exhaust size, 2 inch or 2.5 inch for either a 1.5 or a 1.7 liter engine. I would like to know what are the benefits or faults of using one over the other

A diffusion muffler uses diffuser plates at the end to split up the sound so it follows many different paths. The sound coming out of this type of muffler can be tuned by adding or subtracting diffuser plates. (Contrary to what you might imagine, you get a quieter exhaust system by running fewer discs.) Some hybrid diffuser mufflers also use absorption material to reduce decibel levels even further.

i didn't know this. thanks yeo

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~*REAL WOMEN DO IT ON ALL FOUR*~

i'll be bumping this thread. I would really like to get an answer to my questions please

Bump!

that depends on your engine setup man!!! stock, modified, and what engine too !!!!!!!!!!!!!!!!

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real good stuff Yeo!!

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~empress~

"The only thing friends not suppose to do is let friends drive drunk"

I'm still somewhat confused......

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<a href="http://www.speedtest.net"><img src="http://www.speedtest.net/result/310513520.png"></a>

Great info, great link...

BUMP JUST BECAUSE!

see if you could find an article thats just as comprehensive about NA to forced induction conversions ...

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Toyota Extreme STREET Tuned Engineering Development for Performance

all of this boiled down is simply put - what you like, what yuh engine can take and how deep yuh wallet is

brother Yeo i have a b14 engine in my b11 with a big ole noisy ass muffler that makes people look at me when i drive through Arima cause the expect speed it sounds like a race car, i love the attention sometime but my grandmother hates it nor can i have a convo with a lady when i roll, what i need to know though is it true that big noisy ass chrome tips decreases fuel efficiency?

^ It can, if the muffler is free flow and doesn't introduce any back pressure as the oem muffler, it would affect your power band, more power at higher rpm's but less power at lower revs, so simple things like pulling off from a standstill or overtaking would cause you to have to use more fuel to get a comparable performance as that of stock. It would however allow you to get a higher top speed. Nothing astounding from a stock econo engine though.

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Life is short, Break the rules, Forgive quickly, Kiss slowly, Love Truly, Laugh uncontrollably, never regret anything that made you Smile.

The "backpressure" talk is a myth eh. There's no combustion engine on planet earth that "needs a little backpressure".

See, because your combustion stage in the cycle is a series of controlled "explosions" (let's call them explosions for now) across 3 or more cylinders (in your case, 4 cylinders), there are going to be pulses of exhaust gas flowing through your pipes.

Now, dig this shiznit. Because of the rapid opening and closing of the exhaust valves, there is sometimes cavitation in front of the exhaust pulse and sometimes after. This is a low pressure area, which if comes in front the pulse provides a pressure gradient that allows the exhaust gases to flow out the pipes (let's call this a positive pulse), but if it comes after, it causes the pressure gradient to flow in the opposite direction (let’s call this a negative pulse) and exhaust excavation due to upward piston movement only carries it so far down the pipes.

A proper exhaust system needs to be designed in such a way as to accomodate proper wave propogation to merge these pulses properly for a smooth, consistent exhaust flow (I could carry this back to CXC physics about constructive and destructive interference, but I'd prefer not to). Ideally you’d think that they’d design your exhaust system to cause all the positive pulses to combine and lay the smack down on them roody poo negative pulses, but in real life, positive and negative exhaust pulses travel from your exhaust manifold to the exhaust tip and back in a cycle that, on a factory exhaust, is so friggin smooth, it feels and sounds like a constant, single, uninterrupted flow of gas.

Now, this isn't to say that all factory exhaust systems are designed to fully excavate the exhaust gases from the cylinders. Most times, a portion of the negative wave is desirable to keep some exhaust gas in the combustion chamber.
Here's why this *ahem* exhaust gas recirculation is so important:
1. Exhaust gas ideally cannot be re-burnt, but it still occupies space in the combustion chamber and can be compressed just like normal air. What this means is that it occupies the space that would more readily be occupied by a fresh air-fuel mixture to make more power, but this is for fuel economy purposes, and with an air pump (yeah, your typical internal combustion engine is quite simply an air pump) as inefficient as what we have under our hoods, there's usually a trade-off between economy and performance.
2. Now, hand in hand with the first reason, is the fact that now that there’s less air-fuel mixture all up in there, thus there’s less fuel to burn, thus there’s a smaller flame front and thus less heat and thus…*dun dun dunnnn* lower exhaust temperatures.
3. If for whatever reason, the burn isn’t as efficient as it’s supposed to be (for any number of reasons like overfueling, poor spark, Satan etc.), it’s helpful to put some of that exhaust back in there with some fresh air for re-burning (HA! You thought I said exhaust can’t be re-burnt ent? I said IDEALLY *puhpses softly*). The end result is *drum roll* LOWER EMISSIONS! *bodow*

Tuned aftermarket, oversized exhaust systems increase exhaust gas excavation because of the volume of gas that can now be removed from the combustion chamber (I not getting into a convo about the decreased speed of the gas with the increase in cross sectional area of the pipe right now nuh..we talking volume here), which, while it’s a good thing for power gains (the extent of which is subjective), throws everything I said about factory exhausts off kilter. So, you get poorer fuel economy because you’re messing with them negative pulses, higher combustion temperatures and higher emissions.

Well that and the fact that a fat aftermarket chrome thingie is fun to braaap so el foot is always on the gas.

*Tiger Woods fist pump*

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Tha's too much reading, writing and explaining, i'll stick to mih "lil back pressure" lol

Oh yeah thanks for clearing that up hooky, it's so much easier for me to explain using back pressure than rate & volume of flow and such.

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Life is short, Break the rules, Forgive quickly, Kiss slowly, Love Truly, Laugh uncontrollably, never regret anything that made you Smile.

You missed out by not reading it meng. I thought it was quite informative and mildly entertaining if I do say so myself.

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I did read it Emm. still lmao

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Life is short, Break the rules, Forgive quickly, Kiss slowly, Love Truly, Laugh uncontrollably, never regret anything that made you Smile.