Normal vs swirl center bullet

[faruck]

which one is better??anyone can tell me whats the difference?? help me solve this confusion.. :hmmmm:

 

[DanzEterna]

normal - auto
swirl - manual.

 

[6UE5t]

normal - auto
swirl - manual.

Can elaborate why?

 

[vr2turbo]

Can elaborate why?

Yup, want to know too, because after play turbo just one muffler at the back nothing else.....

 

[tofu_manic]

me no think u can find swirl bullets in japang

 

[DanzEterna]

Can elaborate why?

this was told by a exhaust shop owner to my bro in law when i over head their conversation, didnt bother to know more as mine was decat long time ago, straight pipe from "nenas" till rear muffler like unker vr2turbo

---------- Post added at 02:38 PM ---------- 6 hour anti-bump limit - Previous post was at 02:36 PM ----------

swirl bullets only can be found at ayam brand exhaust shops. havent seen it at those reputable shops yet.
unless akrapovic comes out with the swirl type its worth buying...but price tag pay thru yr nose haha

 

[faruck]

not a satisfying answer that i was lookin for..anyone else?

 

[vr2turbo]

this was told by a exhaust shop owner to my bro in law when i over head their conversation, didnt bother to know more as mine was decat long time ago, straight pipe from "nenas" till rear muffler like unker vr2turbo

---------- Post added at 02:38 PM ---------- 6 hour anti-bump limit - Previous post was at 02:36 PM ----------

swirl bullets only can be found at ayam brand exhaust shops. havent seen it at those reputable shops yet.
unless akrapovic comes out with the swirl type its worth buying...but price tag pay thru yr nose haha

haha.. your Eterna also turbo mah!.....
Actually got. If you look into the bullet the the notch or hole that is on the inside pipe is turning or swirling.. found this picture....


---------- Post added at 02:54 PM ---------- 6 hour anti-bump limit - Previous post was at 02:49 PM ----------

not a satisfying answer that i was lookin for..anyone else?

As far as explanation goes, the swirling one suppose to aid gas flow faster by swirling..

 

[DanzEterna]

not a satisfying answer that i was lookin for..anyone else?

haha sorry bro i was not a fan of centre bullets, but if not mistaken this has been discussed before couple of yrs ago need to dig out the threads.
will try to find out more for u.

---------- Post added at 03:03 PM ---------- 6 hour anti-bump limit - Previous post was at 03:00 PM ----------

haha.. your Eterna also turbo mah!.....
Actually got. If you look into the bullet the the notch or hole that is on the inside pipe is turning or swirling.. found this picture....


---------- Post added at 02:54 PM ---------- 6 hour anti-bump limit - Previous post was at 02:49 PM ----------



As far as explanation goes, the swirling one suppose to aid gas flow faster by swirling..

perhaps it makes the exhaust gas exits the muffler faster? kinda like a tornado style?

---------- Post added at 03:05 PM ---------- 6 hour anti-bump limit - Previous post was at 03:03 PM ----------

u could try reading this, using same method kua..
http://naca.central.cranfield.ac.uk/reports/arc/cp/0130.pdf

---------- Post added at 03:16 PM ---------- 6 hour anti-bump limit - Previous post was at 03:05 PM ----------

found on google..

Swirling Bullet Center Box by Omega
Part of the reason of the loudness / scream like F1 is suspected from the center bullet box. I call it a swirling bullet. Sorry to picture.

The swirling bullet is just a term I made up, don't know the official tech term. It's simply a mid-box silencer kind of thing, but the internal is a swirling shaped perforated tube with fibers inside the walls. Imagine a torque screw kind a look.

Personally I think (from my studies of acoustics) that the physical swirling is only cosmetics and does not do anything to improve performance. In fact the difference between air-speed on the swirl and in center flow is so great that a high pitched scream may be generated.

Since the air-speed difference is so great between the swirl wall and center flow, in reality we "assume" that the true air-flow is only the center section without the swirl. i.e. smaller diameter pipe.

Some times I think if the scream I predict is true that means sound energy is produced and this energy must come from some where and is not free, hence I may have lost some engine power

Don't know may be I think too much. Well, I may be thinking too simple previously. Because that swirling shape, where it's number of turns per distance over xx amount of trunking in (mm) is a function of wavelength which is frequency which is engine rpm.

There is also the issue of steady state air flow versus variable and not to mention the engine valves overlap backwards into the throttles and backwards into the air filter. As this matola muffler is only at it's loudest with full throttle 50% to full throttle.

Oh, well, just ignore me.

 

[tofu_manic]

vr2turbo is dat a picture taken from a locally made exhaust?

imho as long as the majority of reputable aftermarket exhaust makers dont start making swirl type exhausts then it might not be worth it for us to be bothered with it as well

this i think ranks somewhere up there with surbo and gang

 

[faruck]

haha sorry bro i was not a fan of centre bullets, but if not mistaken this has been discussed before couple of yrs ago need to dig out the threads.
will try to find out more for u.

---------- Post added at 03:03 PM ---------- 6 hour anti-bump limit - Previous post was at 03:00 PM ----------



perhaps it makes the exhaust gas exits the muffler faster? kinda like a tornado style?

---------- Post added at 03:05 PM ---------- 6 hour anti-bump limit - Previous post was at 03:03 PM ----------

u could try reading this, using same method kua..
http://naca.central.cranfield.ac.uk/reports/arc/cp/0130.pdf

---------- Post added at 03:16 PM ---------- 6 hour anti-bump limit - Previous post was at 03:05 PM ----------

found on google..

Swirling Bullet Center Box by Omega
Part of the reason of the loudness / scream like F1 is suspected from the center bullet box. I call it a swirling bullet. Sorry to picture.

The swirling bullet is just a term I made up, don't know the official tech term. It's simply a mid-box silencer kind of thing, but the internal is a swirling shaped perforated tube with fibers inside the walls. Imagine a torque screw kind a look.

Personally I think (from my studies of acoustics) that the physical swirling is only cosmetics and does not do anything to improve performance. In fact the difference between air-speed on the swirl and in center flow is so great that a high pitched scream may be generated.

Since the air-speed difference is so great between the swirl wall and center flow, in reality we "assume" that the true air-flow is only the center section without the swirl. i.e. smaller diameter pipe.

Some times I think if the scream I predict is true that means sound energy is produced and this energy must come from some where and is not free, hence I may have lost some engine power

Don't know may be I think too much. Well, I may be thinking too simple previously. Because that swirling shape, where it's number of turns per distance over xx amount of trunking in (mm) is a function of wavelength which is frequency which is engine rpm.

There is also the issue of steady state air flow versus variable and not to mention the engine valves overlap backwards into the throttles and backwards into the air filter. As this matola muffler is only at it's loudest with full throttle 50% to full throttle.

Oh, well, just ignore me.

tq bro

 

[DanzEterna]

faruck,
the best is to get a halfcut performance bullets like hks/apexi etc....rather than this so-called swirling bullets.

 

[faruck]

ok bro..noted with thanks

 

[vr2turbo]

vr2turbo is dat a picture taken from a locally made exhaust?

imho as long as the majority of reputable aftermarket exhaust makers dont start making swirl type exhausts then it might not be worth it for us to be bothered with it as well

this i think ranks somewhere up there with surbo and gang

Not sure brother. Saw in LYN selling second hand....

 

[dD69]

hi guys,

just asking what is the different betwwen midbox and mid bullet (doesn't matter center or swirl).
my car setup extractor > flexible (nenas) > bullet > muffler.

thank you.