I'm using a S flow setup. What is the use of bullet, extractor and CAT/CATless etc etc? When I change my setup, I didn't ask about those issue. Anyone mind teaching me? driving Auto tranny B16A btw.

This post has been edited by richardt3o: Apr 21 2011, 11:51 PM

should be ok i think... whats ur exhaust piping diameter??...
4-1 extractor mainly useful for high rpm usage... perhaps good for high revving engine like campro cps... by using s-flow muffler, back pressure is kept in check so u dont lose so much low end torque....

2 bullet + s-flow muffler still noisy??.. if all 3 are working well (fiber still alot), ur sound level should be around the same as stock standard.... check if any unit of it has worn/burn out fiber inside...

extractor - as its name said, it extracts exhaust pulse out from ur engine... a well tuned extractor creates scavenging effect which helps siphon out the exhaust has from combustion chamber (instead of having ur engine piston to push it out)... generally for inline-4 cylinder engine, extractor (or some people might call it header) is normally categorized as 4-2-1 or 4-1 formation depending on how the piping merge together... 4-1 mainly useful for high rev application while 4-2-1 suitable for street driving where most low-mid torque is utilized... of coz, under each category, there are long and shorts of primary piping and secondary piping to be considered besides having it equal or unequal length... and how collector box merge 2 or 4 pipes into 1.... its basically fluid dynamics theory...

bullet is mainly used to suppress the sound of ur exhaust system... it also acts as a "reservior" or some sort to improve on throttle response... too big "reservior" will create turbulance inside which increases restriction in exhaust flow... while having no "reservior" will reduce throttle response as sudden increase in exhaust gas will have to "wait" or "line up" before exiting at the back....

CAT is a short form for catalytic converter... it is a very special resonator box which converts harmful CO gases emiting from ur exhaust into more environmental friendly CO2 gas.... it contants very expensive material inside, which we take for granted as it restricts exhaust flow.... removing the catcon is illegal in certain country.... but in malaysia, so far we are still not restricted to such environmental law... removing ur catcon improves exhaust flow, which will releases more hidden horsepower....

Okay! I understand ur CAT explanations.

is it right for me to say extractor (header) is link to exhaust?

I dont get anything u said about bullets. LOL! sorry! mind explaining again?

So technically, when I go for a exhaust setup, they will include CAT and bullet?

since i bought an aftermarket mid-tail system, i dunno exactly how big is the diameter...but i think its not too big, around 1.5"-1.6"

Hotbits mid-tail system(1 centre box, 2 bullets, no muffler) vs Turbo S mid-tail system(1 bullet, s-flow muffler)...
which is more silent and which will give more back pressure if the piping diameter is same or almost same??

This post has been edited by responsibleroy: Apr 25 2011, 12:19 AM

How long the fiber can last? if fiber no more already, what can I do? If fiber finish, performance will be affected?

yes... extractor is at the front part of ur exhaust system... attached to ur engine....
bullets are mainly and widely known as noise resonator... it tones down the noise level of ur exhaust... but many exhaust tuner try with different types and size of the bullet to achieve different driving preference...

lets say u are cruising at constant speed at 3k rpm.... the exhaust flow out from ur exhaust will also be constant... when u step on the accelerator pedal, engine suddenly takes in extra air... extra air going in must go out... but during this period, the exhaust flow travelling in ur exhaust pipe is constant... with a bullet, the sudden gush of exhaust pulse will fill up the bullet first... with this, ur engine will still be able to rev freely without having to deal with back pressure of the exhaust...

different engine and different driving characteristics will give u different exhaust setup... ready made "package" allows for general street usage... these "packages" allows buyer to be less blur when changing their exhaust system... of coz, if u know ur fluid dynamics and automotive knowledge well, u can alwiz alter the "common" setting to suits ur own driving preference....

i guess both are almost equally similar in back pressure... having mandrel bent exhaust piping do improve exhaust gas flow... try ask around who had tried both setting to do comparison... i havent tried both of such setting before....

performance will be affected a little... but it will be more on audible side when fiber runs out (or burn out)....
bullet kosong d, change new bullet lor.... just cut and weld new bullet in place only...

there are quite alot of mid section bullets in the market... straight flow oval shape, straight flow round shape, spiral flow, long bullets, etc.... exhaust gas does not need to spiral passing through the piping... it needs to create a smooth pulse which helps in scavenging effect... shape of the mid section bullet determines how much volume inside, which in turn helps ur throttle response, as explained above..

one more thing... exhaust gas is hotter at the front side compare to the rear section because exhaust gas cools down as it flows through the exhaust piping via thermal transfer... exhaust gas travels fastest when it is hot and slows down when it cools... hence, some exhaust shop might recommend u to get a slightly larger piping up front (between extractor till mid bullet) and slightly smaller one at the back (after bullet till muffler)... smaller piping accelerates the exhaust flow so it will exit ur muffler fast... this setup is generally ok.... as long as its not smaller up front and bigger rear end....

i c...
another question...
right now i'm using a fake Apexi Dual Funnel open pod air filter, but planning to change to the priginal one...
is there any significant difference between using the fake and the original one??

there wont be significant difference as long as ur fake one is working fine... what an air filter do is just to filter the air entering ur combustion chamber... it has no magic tricks up its sleeve...

i heard using 4-2-1 extractor with s-flow muffler will give more more top speed than 4-1 with straight flow muffler...
does it mean that more back pressure=more top speed??

its not the more the better... the key is to get the optimum flow and back pressure for best performance preference...

4-2-1 extractor gives more top speed than 4-1 right??
can u explain about this??
i mean on how 4-2-1 works that it gives more top speed than 4-1...

terbalik la
4-1 more top speed because the flow is not restrited
4-2-1 more on mid band power because on mid engine speed the restrition is low and later on high end the restriction start so top end power lose out to 4-1

restriction logic
easy logic 1
imagine a water tap
u put extra large hose the water flow out not strong rite
if put suitable size the water will shoot out rite
but if water volume is alot then the mid size pipe wont be suficent

all i can say... 4-2-1 gives better mid-range torque... while 4-1 gives better horsepower at higher revs.... that is only the extractor configuration... piping diameter, primary and secondary piping length ratio, all takes into configuration in creating a suitable extractor for ur needs....

Hi all sifu, i wanna ask that is midpipe with center bullet or box will better for auto car?for back pressure. currently mine is 4-2-1 , mid stock and straight flow.Any Recommend?

This post has been edited by william85: May 7 2011, 03:05 AM

tak faham
centre bullet and box not the same thing ka ???

center bullet got round and oval shape mia maa... ask unker bring u go jianhang lepak more laa....

my swift auto setup 4-2-1, stock mid pipe and straight muffler(HKS silent hi-power) is quite noisy. wanna change mid pipe any suggestion on mid pipe? to reduce the noise and increase abit on back pressure ya. i'm newbiez on exhaust.

change ur muffler to the tabung ones but straight flow inside not s-flow tabung....nothing much on the mid box....

How about swirling bullet? will it reduces the noise?

4-2-1 extractor,one bullet(dun use swirl one,will more noisy),one mid box and s flow muffler..tis is d way to minimize the sound..