Proven Rear Cannons That Actually Work

[SirRacer]

ive got an hks superdrager on my s14 and it sounds absolutely mint. no drone yet sounds touch and is reasonably quiet

one cannon muffler and a tiny one, no cat

[666DAN]

My magnaflow is awesome, flows tons, doesn't cause a fuss or unwanted attention, sounds great!

[sinistaGTR]

^^^ just those number plates i love em but lol great name

[gtst25]

Thanks for the replies,

Looks like I'll be looking the longest oval shaped rear muffler with the biggest body that will fit. I don't think the stupidly big exhaust tip on the existing cannon helps either - just must just amplifies everything.

There's a big difference with load too - if there's only one or two of us in the car it's ok, but with five people onboard and a boot full of bags it's just too loud until you hit about 3600 rpm (120k's) and the noise falls.

Cheers

Edited December 13, 2006 by gtst25

[khunjeng]

I had a HKS superdragger ...it would drone..but it had some holes near the join...

I have 2 x 2.5" cannons now...but I didn't install a mid muffler so its quite loud...I will install another one today along with a clutch...

Looks hot...but I have silencers in there cos its too loud...but soon it will be cool.

[grigor]

If you want less 'drone', muffle the sound by fittign a more restrictive exhaust, such as an oval muffler, and/or a centre muffler.

Yes it was beautifully quiet when the 3" "heavy duty turbo" mid mount was new. You could actually hear wind and tyre noise as you drove along.

It lasted 1-day on the dyno and the packing cooked, turning the muffler into an expensive pipe.

High performance hot/loud engines (like rotaries and turbos) need stainless muffler packing.

[MANWHORE]

an oval muffler doesn't really restrict the exhaust more. it just has a bigger body for the sound particles to dispense their energy. if you have 2 mufflers, both with a body 30cm long, and a 3" pipe through the centre, which ever has the biggest area outside of that centre tube will be quieter (however this also depends on the packing inside the muffler).

Oh course it does. You said that the sound particles 'dispense their energy'. How? by slowing down.

As you said, it passes through the packing material.

The restriction may not be noticeable on a mildly modded car. That is, it might not be a restriction at X power level. e.g. at 200 rwkw, a 3" exhaust flows heaps, so any difference might make 5 rwkw difference. However, on some of those 1400 bhp japanese gtrs, having a straight through setup with only one cannon at the end, or two oval mufflers will make a lot of difference.

[ix9]

Ive been told hte Trust PEII cannon is fairly quiet, still wont be as quiet or dronless as the oval mufflers though.

I have the Trust Power Extreme II system, its PURFECT! No drone whatsoever, and when you open it up it has ANGRYGROWL Couldn't ask for a better system.

The PEII is cat-back, but before that I have custom split/stainless dump, RS*R Front Pipe, De-cat pipe then the PEII system - Just FYI

The PEII consists of a center muffler and a rear cannon btw

[mad082]

Oh course it does. You said that the sound particles 'dispense their energy'. How? by slowing down.

As you said, it passes through the packing material.

The restriction may not be noticeable on a mildly modded car. That is, it might not be a restriction at X power level. e.g. at 200 rwkw, a 3" exhaust flows heaps, so any difference might make 5 rwkw difference. However, on some of those 1400 bhp japanese gtrs, having a straight through setup with only one cannon at the end, or two oval mufflers will make a lot of difference.

what you are missing is that the mufflers have a perferated tube through the centre. there is only a certain amount of air going through those holes and into a muffler. so 2 mufflers with the same perferated tube through the centre are going to allow the same amount of air into the muffler. the bigger body just has the ability to reduce the noise more.

the sound particles don't flow in the same path as the air. they bounce along the pipe, where as the air flows through it more smoothly. when they get to the muffler they go in and bounce around in there and disperse their energy in the packing.

if the big horsepower cars were hugely affected by mufflers they'd use the cheap and nasty ones you get from supercheap that have tiny bodies, not ones like the hks ones that a big body.

[Beer Baron]

i'm not a fan of those sound controllers. you want air to spin as it flows to increase air speed and having a plate in the is only going to create turbulence.

very interested in this 'spinning air' theory. does it spin like a ballerina? or is it more smooth like a spinning top? also does clock-wise vs anti clockwise affect power much?

[Beer Baron]

i will add one nugget of advice i've learned in regards to tone of the exhaust and drone. thin walled stainless exhausts are more prone to be drony in their note than a comparable thicker walled mild steel system. infact some of the nicest notes i've heard came from mild systems. the shape of the exhaust also has a big impact on note (ie how long the straight sections are). muffler choice is also important, dont buy one of the cheap x-force etc. they do not have very much packng, and it's not the good stuff. the japanese brand ones on the whole use better materials and have a higher standard of manufacture.

[MANWHORE]

what you are missing is that the mufflers have a perferated tube through the centre. there is only a certain amount of air going through those holes and into a muffler. so 2 mufflers with the same perferated tube through the centre are going to allow the same amount of air into the muffler. the bigger body just has the ability to reduce the noise more.

the sound particles don't flow in the same path as the air. they bounce along the pipe, where as the air flows through it more smoothly. when they get to the muffler they go in and bounce around in there and disperse their energy in the packing.

if the big horsepower cars were hugely affected by mufflers they'd use the cheap and nasty ones you get from supercheap that have tiny bodies, not ones like the hks ones that a big body.

I disagree with you.

I didn't want to start talking physics, but sound is not a particle. I've included some basic information below about the nature of sound waves:

First, there is a medium which carries the disturbance from one location to another. Typically, this medium is air; though it could be any material such as water or steel. The medium is simply a series of interconnected and interacting particles. Second, there is an original source of the wave, some vibrating object capable of disturbing the first particle of the medium. The vibrating object which creates the disturbance could be the vocal chords of a person, the vibrating string and sound board of a guitar or violin, the vibrating tines of a tuning fork, or the vibrating diaphragm of a radio speaker. Third, the sound wave is transported from one location to another by means of the particle interaction. If the sound wave is moving through air, then as one air particle is displaced from its equilibrium position, it exerts a push or pull on its nearest neighbors, causing them to be displaced from their equilibrium position. This particle interaction continues throughout the entire medium, with each particle interacting and causing a disturbance of its nearest neighbors. Since a sound wave is a disturbance which is transported through a medium via the mechanism of particle interaction, a sound wave is characterized as a mechanical wave.

Edited December 14, 2006 by MANWHORE

[Aif]

maybe try putting a resonator in? i have a 3inch exaust with a res and a overly sized 7inch cannon tip and it sound hella good.

[666DAN]

Yeah my whole system between the front pipe and muffler is mild steel to help with the tone also.

[GeeTR]

I disagree with you.

I didn't want to start talking physics, but sound is not a particle. I've included some basic information below about the nature of sound waves:

First, there is a medium which carries the disturbance from one location to another. Typically, this medium is air; though it could be any material such as water or steel. The medium is simply a series of interconnected and interacting particles. Second, there is an original source of the wave, some vibrating object capable of disturbing the first particle of the medium. The vibrating object which creates the disturbance could be the vocal chords of a person, the vibrating string and sound board of a guitar or violin, the vibrating tines of a tuning fork, or the vibrating diaphragm of a radio speaker. Third, the sound wave is transported from one location to another by means of the particle interaction. If the sound wave is moving through air, then as one air particle is displaced from its equilibrium position, it exerts a push or pull on its nearest neighbors, causing them to be displaced from their equilibrium position. This particle interaction continues throughout the entire medium, with each particle interacting and causing a disturbance of its nearest neighbors. Since a sound wave is a disturbance which is transported through a medium via the mechanism of particle interaction, a sound wave is characterized as a mechanical wave.

Thank Christ for your cut and dump, I was about to unleash some fury! "Sound Particles"?? FFS

I have a Trust PEII cat back, and can vouch for their civility. Mines actually almost too quiet (although EPA tested it at 101dB, with a 107 pop when I backed off) Seriously, they are that quiet… my engine fans louder.

There is no such thing as 'drone'. The sound that you don't like is basically the loudness.

If you fit an oval muffler, why is there less 'drone'? because it's simply softer.

There is such thing as “drone” my friend.

Its quiet distinctive, and sounds far removed from ordinarily scaled “perceived sound level”

Its when the gas going through the pipe, hits the units (as a whole system, including the pulsing exhaust valves) resonance frequency.

On a response graph, of sound pressure of the entire freq spectrum, you’ll find a natural “blip” or a high point – that’s the resonance freq.

Bass bandits take advantage of this by using a sample tone, that’s dead on the point to give a boost in pressure for competitions.

It’s so annoying because the human ear picks up a 3dB increase as a perceived doubling in sound… so if your unlucky anough to have your resonance freq occur at 5th gear, 100km/h, when you hit that you’ll hear / feel a quiet distinctly LOUDER sound = that’s the drone ppl speak of.

As its causes by sound wave lengths doubling up and super opposing“ I think the term is? Anyone know of top of their head?

Beer Baron’s dead right, with zhaust material, thickness and design all playing a role in the resonance freq, exactly like any wind instrument.

Anyway, that’s what old school “resonators” are for, trying to alter that point so it doesn’t occur in the normal operating exhaust gas speeds.

A mate has only one muffler on a 550hp+ 13B BP turbo, and it does a good job, without drone. It’s a custom muffler from somewhere in Sydney I believe. Ill edit this post later

[BAMR33]

Any have a Rein hard exhaust system. I've heard they sound hot.

[djr81]

very interested in this 'spinning air' theory. does it spin like a ballerina? or is it more smooth like a spinning top? also does clock-wise vs anti clockwise affect power much?

Gees Baron. Which way its spins depends which side of the equator you are on. Everyone knows that.

[kiwi32]

On my rb30 im using a 3inch mild system with one resonator in the middle and one oval muffler at the back. The turbo exhaust housing is .84 and the waste gate is plumbed back, at 100ks it is very quiet and it also has a very nice sound on boost, but at 80ks it drones so bad you can feel it inside your head.

[saliya]

There is no such thing as 'drone'. The sound that you don't like is basically the loudness.

If you fit an oval muffler, why is there less 'drone'? because it's simply softer.

If you want less 'drone', muffle the sound by fittign a more restrictive exhaust, such as an oval muffler, and/or a centre muffler.

Kind of.

"Resonant frequency" is something that means a little here. Perhaps the exhaust system is louder at cruise RPMs

(who on earth would tune for that, but I digress...) than at other RPMs - hence, the term 'drone'.

Yes, it's louder; but it's louder where you would not expect it to be - a harmonic of a wave is making it louder

than you expect it to be...

And to mad082: yes, mufflers _can_ change in size without materially altering flow - yet have very different

sound outputs. Once again to do with resonance and interference of sound waves...

Regards,

Saliya

[CORBSTR-32]

As its causes by sound wave lengths doubling up and super opposing“ I think the term is? Anyone know of top of their head?

There is no such thing as 'drone'. The sound that you don't like is basically the loudness.

i believe the word your looking for here is super impose .. if memory serves me correctly

super imposition is caused by two sound waves, when they meet they either cancel eachother out or add to eachother to make a greater sound. I'd say its got more to do with resonance than super imposinig.

Its all about harmonics, the resonant frequency depends on the length of the pipe. i have the formulars around here somewhere, if the exhaust gas is shooting through the exhaust pipe at a certain frequency or wave length if you like, and the pipe is the right length you would set up a standing (sound) wave (refered to as a harmonic) this causes resonance, and resonance is what you dont want, resonance is waht amplifies the sound wave through the pipe, hence drone. resonance would occur at different rpm's deppending on exhaust, but a jap exhaust would probably be at tuned lengths to try and eliminate this i would think

if your budget allows try to get a good quality one, the cheap ones are thin walled and tend to sound a bit tinny. Im in the market for an exhaust and i dont think i can go past the trust pe2, ive heard it first hand and it sounds so nice especialy when you give it some