.: Exhaust Modification Corner :.

[Wild_Seven]

Modified S-flow muffler and the stock sflow muffler , the difference is inside the muffler box itself. Stock sflow muffler has many blocks while the modified sflow muffler has less blocks. Less blocks give better throttle response and also better acceleration power. Besides, inlet size will be slightly bigger than stock muffler, which gives better exhaust flow. Stock sflow muffler performs the best at very high rpm, thus, for those who wants sflow muffler but do not revv so high, you need to get modified sflow which provides u the peak of torque at a little bit lower rpm than stock. Hope you guys get what i mean.

S Flow mufflers usually have 3 chambers, meaning to say the exhaust actually flow all the way to the middle chamber of the box, then to the front chamber and finally to the rear chamber and this is only an example as there are many variations to the S flow design. Sometimes there is even a bypass pipe between the middle and rear chamber.

Less blocks need NOT necessarily gives better throttle response and acceleration as it lessens BACK PRESSURE. Normally aspirated cars need sufficient back pressure to generate torque, unlike Forced Induction equipped cars. (Similarly to the piping size). Less chambers will also likely to cause the exhaust to be louder. Bigger pipes will also cause a drop in back pressure and increase in loudness.

General Rule of thumb, increase of pipe size and decrease of chambers will lessen back pressure and hence loss of low end torque but will result in a slight gain of HP in the top end. As in the Golden Rule of Creation, you cant create something out of nothing.

 

[fazrul]

1st of all.. cheers and great thread!
question : i got 2" muffler if i change to stock which 1.5" muffler izzit ok? or any problem will accour. thx in advance .. bump for kent20 :)

 

[donCityZ]

thanks all for sharing ur views...

Im sticking to stock muffler. :) my priority still want to maintain
my excellent low end torque which i gained from changing
extractor. hi speed i don care so much.. the fastest i went
also is 180km/h.. and at that speed, my car is saying to me..
"What tha f*ck are u doing???!!!!".. kekekeke.... mostly
160km/h at hiways is stable and good cruising edi...

 

[kent20]

1st of all.. cheers and great thread!
question : i got 2" muffler if i change to stock which 1.5" muffler izzit ok? or any problem will accour. thx in advance .. bump for kent20 :)

no problem one i think your toquer will be inscressed if u do so..

 

[kent20]

this is what inside a good S-FLOW muffler

this warlock like very nice can be sflow also can be striaght flow thinking to order man!!

 

[nitrus]

kent! ahaahaa.. wassup dude..

weng, i was told that some exhaust shops make their own straight-flow mufflers, and they specially have a silencer in it to silence the noise ...

will those silencer thing create more backpressure ?

hahahahaha one time i was so particular in the noise that one guy told me 'just stick back to s-flow" .. lol !! damn ..

weng, if i like the idea of "fast but silent" car ... which/what muffler do u think best suits me?
with the balance of power and noise ..

 

[Wild_Seven]

Nitrus, there is no such thing as the perfect exhaust. Probably the closest to it is the original exhaust as the car maunufacturer would have spent plenty of R&D to get the optimum result, a compromise between torque, hp and noise.

 

[kweng84]

nitrus: i guess much have said via msn..so briefly, silencer does give backpressure/restrictions that manual cars dont need any. Eliminate it. Just like why we go and ditch out CAT CONs. Make your choice bro..u want power, u must accept sound..

 

[kweng84]

Wild_Seven sifu..well said in ur previous post. I agree with you especially that you've said bigger piping size decreases low end torque. It actually gives better high end power(top speed) ,but not the bigger the better. If too big, exhaust system pulse will be ruined(need some explaination on the pulse, anyone pls..) and thus, power loss. Rite bro?

 

[kenzo]

heya bro kent20, now im gonna use ur zenden extractor (bila lah boleh collect :P) then 2inch all the way with 1 bullet and 1 midbox and straight flow muffler, ok ke? i thought of using 1.8inch piping, but i wanted kao kao high rpm top end power, any idea?

 

[Shinjite]

This is my setup for my Wira 1.6 AUTO
4-2-1 extractor + 2" piping mandrel bend with bullet + Sflow muffler
Its good :)

 

[Shinjite]

heya bro kent20, now im gonna use ur zenden extractor (bila lah boleh collect :P) then 2inch all the way with 1 bullet and 1 midbox and straight flow muffler, ok ke? i thought of using 1.8inch piping, but i wanted kao kao high rpm top end power, any idea?

What car are u using bro? For piping calculations, use the 25% factor. Must be not more than 25% increase

 

[Massive_InfusioN]

Good Day,

Im using a Gti with stock exhaust system. But on the engine side i have done high cams, and open pod K&N. Planning to upgrade the exhaust now. And need your advice on my idea.

my idea is to maintain the standard rear muffler. But to install a stright pipe all the way to replace the stock piping. (taking off cat-con & silencers). I still like the standard muffler and to reduce noise.

Is this set-up advisable?

 

[nitrus]

I think it would be fine Massive_Infusion , same like me, i prefer silence altho if i have a little power lost due to backpressure .. But it's all good ..

U will hear more better advise from sifo kweng :regular_smile:

 

[Shinjite]

Good Day,

Im using a Gti with stock exhaust system. But on the engine side i have done high cams, and open pod K&N. Planning to upgrade the exhaust now. And need your advice on my idea.

my idea is to maintain the standard rear muffler. But to install a stright pipe all the way to replace the stock piping. (taking off cat-con & silencers). I still like the standard muffler and to reduce noise.

Is this set-up advisable?

Shouldn't be a problem :)

 

[kweng84]

Good Day,

Im using a Gti with stock exhaust system. But on the engine side i have done high cams, and open pod K&N. Planning to upgrade the exhaust now. And need your advice on my idea.

my idea is to maintain the standard rear muffler. But to install a stright pipe all the way to replace the stock piping. (taking off cat-con & silencers). I still like the standard muffler and to reduce noise.

Is this set-up advisable?

Well, you got high cams,open pod k&n, it is a very wise choice u have there in modding exhaust system.

Your ride has a good head power but no 'tail'. Stock muffler is very restrictive having small inlet piping size, big blocks which creates back pressure which you dont need it. If you want good high end power with low end/middle end increased, get a good 4-1 extractor, change 2" full piping, take off CATCON, take off the twinpipe sflow muffler and replace it with a nice good 2" straight flow muffler which means single exhaust system. (Juz my 2 cents, based on the experience of modding few GTI's exhaust).

 

[kweng84]

I think it would be fine Massive_Infusion , same like me, i prefer silence altho if i have a little power lost due to backpressure .. But it's all good ..

U will hear more better advise from sifo kweng :regular_smile:

bro, me no sifoo ler.. just that i think if start mod exhaust, mod the best way and smart way lor..if want silent cum power, very hard ler..not so perfect one..rite??

 

[nitrus]

yeah lor ... so i can only have silent with some power lost .. hahhahaaa...

 

[Shinjite]

GTi isn't it better with 2.2" piping?
Same with MIVEC? MIVEC engines best is around 2.2"/2.3"

 

[kweng84]

GTi isn't it better with 2.2" piping?
Same with MIVEC? MIVEC engines best is around 2.2"/2.3"

2.2" piping really for dragger style drivers...dont think it is suitable for 50:50 highway/city drivers...