I am thinking of changing the entire exhaust system on my 1.3 Iswara.
But now... i'm facing a dilema.

Should i change the stock to larger 4-2-1 header or 4-1 header?

Anyone got comments on which is better for the iswara 1.3 engine?

My car modding adviser tells me to change the default stock 4-2-1 to a larger piped 4-1 header; and that it would add more pickup.

What do you guys think?

ur car is auto or manual? ppl said auto go for 4-2-1, manual 4-1.. hope dis helps..

get 4-2-1 extractor....

its a manual...

4-2-1...engine stock?..piping stock?..

i use 4-1 then change to 4-2-1.

if u wan torque then better use 4-2-1, but reving 4-1 better, very easy rev, rev till 8k also shiok

i was using the old iswara, best bang for bucks is sanding the carburator.

if u wan pick up at low rpm i think 4-2-1 is more suitable if 4-1 is more to high rev.

Go for the 4-2-1.
Not many people can get the hang of the 4-1 setup.

You changing your muffler as well?

what u mean by sanding the carburetor??..

I think he means porting/polishing the carb

icic... i jz woke up... blur abit...

Bro xtorm, do you know of any w'shop in Klang Valley that can do a good job in porting the carb and usually how much does it cost usually?

currently i am using stock 4-2-1. exhaust piping changed from the midbox onwards. changed to larger piping and muffler s-flow marco muffler.

so 4-2-1 for midrange rev power while 4-1 is for high rev power?
i guess 4-2-1 will save alot of fuel since the engine doesn't need to be revved high to achieve tourque. but issit true that 4-1 set up will deliver a better pick up overall?

rev till 8krpm burn alot of fuel kao kao ar? xD

This post has been edited by tineagle: Apr 22 2008, 05:46 PM

yes if u rev till high high... at high rpm, ur revs is vr smooth... no restriction at the exhaust...
but low rpm pickup will suffer if u use 4-1 extractor...

rev till 8k burn alot of fuel only... wont burn kao kao one...

sand as in using sand paper and sand the inlet parts, or should i say mouth?

DIY...hahahaha, damn i miss the sound and pull of it.

1 more question. does a bullet provide better airflow than a midbox? whats the diff between the two?

midbox is more restrictive compare to a bullet....

midbox is just an empty metal tabung,since it has a higher volume,the exhaust gas gets slowed down..the best setup will be to keep the velocity of the exhaust gas high so it can exit the engine without restrictions and the fastest possible way..i dont understand why people say backpressure is necessary..i think the best setup will be a straight pipe from the extractor till the end but this is bloody hell loud hence the need for muffler and bullets..

This post has been edited by ryan_hustler: Apr 24 2008, 11:12 AM

Google up "exhaust scavenging"...

go exhaust shop and try it out urself.... den u'll understand what we meant...

leave ur extractor stock....extractor is one of the most sensitive parts in an exhaust system. unless ur getting a branded extractor which has been properly measured, tuned and bent...forget about it. im not a believer in custom extractors...

as for topic... urs is a 1.3 meaning torque is plus for normal daily use driving id say get 4-2-1 since ur gonna need the extra oomps on low-mid revs to help make up for the lack of torque.

only go 4-1 if u intend to keep ur car at high revs. aka drag or track alot. 4-1s are good at high revs... low-mid revs...4-2-1 better.

backpressure is mainly attributed to auto transmission. manuals..backpressure is a nono. though i have no idea how backpressure affects autos.

as for straight exhaust setup..not the best ler... best would be direct from ur extractor and straight comes out in front of ur front tire or at the side

hi all,

actually the campro auto 4-2-1 or 4-1 is better?

i am looking for improve torque. many say 4-2-1, but i go to 2 exhaust shop in penang, both bos tell me go for 4-1....blurr liao.

finally, one of the exhaust shop bos tell me, just do the decat and stick with the ori extractor. RM80 oni and traid in the ori cat converter.

after decat, can feel engine lighter, but not very significant.

confirm 4-2-1. go for R3 or Hotbits/powerzone.
4-1 only gud for high revving engine.

Where is your location?

penang

Regardless whether its an auto or a manual car, just use 4-2-1.

I have tri-y setup (aka 4-2-1) bullet...then s-flow muffler.

torque improved bit, but noticeable. exhaust sound is not that loud, when you pick up baru loud louder. I m thinking modding into bigger diameter piping, but i scare of the fuel consumption.

Anyone tried bigger diameter piping? mine still stock size piping.

mines on 1.6", not a huge difference to be honest.
low hp low torque, and on a 3 speeder auto to boot.