Mine S-flow only, hear what lah.....

Is it nobody can help me to answer my question?another question is my bullet n midbox distance onli 4inch,is it oso wil affect top speed?

haha suddenly got mufflers/exhaust pipe TT, interesting.

IMHO, d distance is not d big question... d big question is d diameter of pipe in between of dat 2...

piping diameter still is original..if i take out the bullet and use the midbox onli,isit performance still remain same or more worse?

this 1 need ask d exhaust specialist dat put 2 muffler for u.. in velocity terms, it doesnt matter, onli d sound might b louder abit..in pressure wave tuning, m not sure..

i asked around 3 exhaust shop oledi..all told me different story..one told me take out is same,one told me the distance of bullet and midbox too near,need extend to 12inch lo..so i hope sifu here can help me

bullet and mid box are the same thing
both job is to suppress sound of the exhaust and will create back pressure
as for answer i cannot answer u as i am reading ur describtion here rather than looking at ur bullet design/inlet and outlet bla bla bla and i am not a bomoh so i cannot give the answer that will 100percent accurate
but in general law less restriction is better in way till ur exhaust still can maintain the scanvenging effect
if scanvenging effect if affected it will be bad news

jomla.when? a group of 4-5 ppl also good engh cn see u guys cars

i guess kelisa stock gear ratio at higher gears are not meant for accelerating, more for cruising so its more difficult to spin the engine faster at higher gears to achieve high rpm, so more difficult to get high exhaust velocity. i think the same goes for most daily car stock gearboxes.

thats why 3-1 or bigger piping really good for pickup, at lower gears its easier to go i.e. 7-8k rpm and bigger pipe size can be used effectively in this case

ooh fark..lets do it hahaha

---

Added on October 12, 2011, 2:57 amkeep the 4-2-1, keep stock piping, if midbox is straight and has larger diameter internal pipe than bullet, then keep it and remove the bullet, remove s-flow and replace with straight flow muffler that has same internal pipe size as ur stock piping or close enough. Make sure straight flow muffler at the back has diameter not more than 0.5" from ur stock pipe but if u can find same size is always the best, can use more than 0.5" but not efficient so best to avoid. most exhaust shop will say can use much bigger diameter muffler but does not say whether it is the best for ur car

midbox position plays a big role in the exhaust powerband so pay attention to the location in ur system. basically shorter distance between midbox and extractor will boost power at high rpm and longer for lower rpm.in general 12-18" for higher rpm, 18-30" for midrange and 30-42" for high torque at lower rpm, but anything shorter than 12" can lose out on potential power plus its not possible to fit a midbox at 12" after extractor, that would be near gearbox or crossmember d. i think for auto its best to use distance between low and mid range, something like 24-36" as gear shift point is usually in this rpm area

more specific distance i would need some info on ur engine.

noise wise, i like to think of the noise level of a muffler as a function of its body to pipe size ratio. when comparing 2 mufflers, i.e. given the same body dimension, the smaller internal pipe will sound much lower. so if u have a tight noise regulation rule, get the biggest body muffler u can fit under ur car having smallest internal pipe that flows enough for ur engine and application. plus silent and fast car looks more sophisticated hehehe

bottomline, never use sflow if power is what u want.

This post has been edited by upontheriversky: Oct 12 2011, 03:02 AM

[quote=upontheriversky,Oct 12 2011, 02:28 AM]
i guess kelisa stock gear ratio at higher gears are not meant for accelerating, more for cruising so its more difficult to spin the engine faster at higher gears to achieve high rpm, so more difficult to get high exhaust velocity. i think the same goes for most daily car stock gearboxes.

thats why 3-1 or bigger piping really good for pickup, at lower gears its easier to go i.e. 7-8k rpm and bigger pipe size can be used effectively in this case
ooh fark..lets do it hahaha

---

Added on October 12, 2011, 2:57 am

keep the 4-2-1, keep stock piping, if midbox is straight and has larger diameter internal pipe than bullet, then keep it and remove the bullet, remove s-flow and replace with straight flow muffler that has same internal pipe size as ur stock piping or close enough. Make sure straight flow muffler at the back has diameter not more than 0.5" from ur stock pipe but if u can find same size is always the best, can use more than 0.5" but not efficient so best to avoid. most exhaust shop will say can use much bigger diameter muffler but does not say whether it is the best for ur car

midbox position plays a big role in the exhaust powerband so pay attention to the location in ur system. basically shorter distance between midbox and extractor will boost power at high rpm and longer for lower rpm.in general 12-18" for higher rpm, 18-30" for midrange and 30-42" for high torque at lower rpm, but anything shorter than 12" can lose out on potential power plus its not possible to fit a midbox at 12" after extractor, that would be near gearbox or crossmember d. i think for auto its best to use distance between low and mid range, something like 24-36" as gear shift point is usually in this rpm area

more specific distance i would need some info on ur engine.

noise wise, i like to think of the noise level of a muffler as a function of its body to pipe size ratio. when comparing 2 mufflers, i.e. given the same body dimension, the smaller internal pipe will sound much lower. so if u have a tight noise regulation rule, get the biggest body muffler u can fit under ur car having smallest internal pipe that flows enough for ur engine and application. plus silent and fast car looks more sophisticated hehehe



bottomline, never use sflow if power is what u want.

[/quote

my car is campro 1.6.so tat means after i take out d bullet,d performance oso same,rite?if i use bec ori midbox instead of my current midbox,is it ok?

---

Added on October 12, 2011, 8:13 am[quote=upontheriversky,Oct 12 2011, 02:28 AM]
i guess kelisa stock gear ratio at higher gears are not meant for accelerating, more for cruising so its more difficult to spin the engine faster at higher gears to achieve high rpm, so more difficult to get high exhaust velocity. i think the same goes for most daily car stock gearboxes.

thats why 3-1 or bigger piping really good for pickup, at lower gears its easier to go i.e. 7-8k rpm and bigger pipe size can be used effectively in this case
ooh fark..lets do it hahaha

---

Added on October 12, 2011, 2:57 am

keep the 4-2-1, keep stock piping, if midbox is straight and has larger diameter internal pipe than bullet, then keep it and remove the bullet, remove s-flow and replace with straight flow muffler that has same internal pipe size as ur stock piping or close enough. Make sure straight flow muffler at the back has diameter not more than 0.5" from ur stock pipe but if u can find same size is always the best, can use more than 0.5" but not efficient so best to avoid. most exhaust shop will say can use much bigger diameter muffler but does not say whether it is the best for ur car

midbox position plays a big role in the exhaust powerband so pay attention to the location in ur system. basically shorter distance between midbox and extractor will boost power at high rpm and longer for lower rpm.in general 12-18" for higher rpm, 18-30" for midrange and 30-42" for high torque at lower rpm, but anything shorter than 12" can lose out on potential power plus its not possible to fit a midbox at 12" after extractor, that would be near gearbox or crossmember d. i think for auto its best to use distance between low and mid range, something like 24-36" as gear shift point is usually in this rpm area

more specific distance i would need some info on ur engine.

noise wise, i like to think of the noise level of a muffler as a function of its body to pipe size ratio. when comparing 2 mufflers, i.e. given the same body dimension, the smaller internal pipe will sound much lower. so if u have a tight noise regulation rule, get the biggest body muffler u can fit under ur car having smallest internal pipe that flows enough for ur engine and application. plus silent and fast car looks more sophisticated hehehe



bottomline, never use sflow if power is what u want.

[/quote

my car is campro 1.6.so tat means after i take out d bullet,d performance oso same,rite?if i use bec ori midbox instead of my current midbox,is it ok?


This post has been edited by samwongjyhhorng: Oct 12 2011, 08:13 AM

Hear your brop brop brop..

Suggestion only wei..hehe..if majority mau TT ok la we proceed..
For learning process also what..because exhaust system i think its quite subjective..

Hai bomoh.last time u tried my car with stock nenas.
Come try again with this 2 inch nenas pulak..

JOM! but...where u guys staying leh?

im staying sunway area...weekends at kajang

kanasai. meet up around sunway la.... wan go dyno ma... uponskyriver u dyno d? mayb we go dyno la..huhu.. easier to chat wit graph infront us

wei mau dyno ka? adoi next month la..this month koyak liao..

next month a

see wat upondskyriver say 1st lo.. actually wanna dyno wit him since 2 weeks ago.... jus no time..zzz


waaa... speedworks rm100 per run...so expensiv.... http://www.speedworks.com.my/dynamic_test_systems.aspx

millenium shawnz told me rm60 for 3 runs..

wow so cheap. i did 100 (((((( anyway let me know when tt

wan TT? aiyah...Banshee not out of ICU...and even if its out.. need to run in the engine and retune...then only can rev kow kow hahahha

want to wait also caaaannnnnn...
confirm paling bising gila punya..

hi

I drive a Xtrail 2.0 2005 year AT car, NA with K&N drop in. I've been looking around to upgrade my exhaust. The stock setup is currently 4-1, cat, bullet, (looks like U-shape) muffler . I'm looking for a everyday city drive, therefore are looking at 4-2-1 setup. My usual AT drive, autogear changes on around 2.5k-3k rpm. at most, i'll hold it till 3.5k rpm but never passes that. my drive is always below 140kmph on highway, and city about 100kmph. I'm looking for torque-y at lower rev and for faster speed recovery without the sacrifice of FC. as the chinese thinking goes, better if can improve on FC along with the rpm powerband. current FC is about 7.6km/ltr or 13L/100km. ideally, I am looking at 11L/100km or 9km/ltr.

the car specs are as follows:

Displacement (cc): 1998
Arrangement and No. of cylinders: Inline 4-cylinder
Type of combustion chamber: Cross-flow, pentroof
Valve mechanism: Chain-drive DOHC with 4 valves/cylinder
Fuel system: Port injection
Bore x stroke (mm): 89.0 x 80.3
Compression ratio: 9.9:1
Valve head diameter (mm): Intake: 35.5; Exhaust: 30.5
Cylinder bore pitch (mm): 97.0
Crankshaft pin-journal diameter (mm): 45.0
Crankshaft main-journal diameter (mm): 55.0
Connecting rod length (mm): 152.9
BTDC: 26
ABDC: 30
BBDC: 29
ATDC: 3
(see http://www.4freeimagehost.com/uploads/fb412ebc1dee.png)

I had been reading some of the forum replies (of recent ones), and this is just based on my understanding,

1) I need a (2.0 cc * 2L =) 4L bullet volume?
2) stick with 1.6" diameter pipping and stock muffler (i think it's U-shape)?
3) i don't think i want to go for hotbits due to rumours of "cracks".
4) how do I go about calc the tuned length of extractor and collector, or length before the termination box ie bullet/midbox? Staying at 3500RPM, and I played around with the online calculators, it was recommended that I'll go with extractor header of 48" (15"+33"). Is this correct? I am still at loss how to go about getting the length of collector.
5) I'm leaning against taking out the cat, and if I don't, kind of defeat the whole purpose right?
6) what will be your recommendation for the whole setup?

thanks.