I am the owner of 2004 1.5GLI fuel injection SVDO manual sedan wira.
I have the problem of my car pick up was no power, car were drag and heavy when change gear from 1 to 2.

After get some advice from forum and mech.
I plan to change the following items:-

1. Good Spark Plug
2. Air Filter
3. Whole Exhaust System (4-2-1 Extractor, bullet and muffler)

But, different people have different advices and comments. Make me confuse what should i go for it.

Q1. Some said small Cc cars go for drop in air filter that will be good enough, if use open port the performance become worst. But, some said manual car go for open port to get better performance. Which statement is correct?

Q2. Some said if you want pick up go for 4-2-1 extractor, top speed go for 4-1 extractor. some said manual car go for 4-1 extractor to get better performance. Which statement is correct?

Q3. Some said s-flow muffler for pick up and more silence, straight muffler for top speed and more noisy. but, my mech advices me s-flow no power, straight can improve pick up, top speed and can select the types that not so noise. Which statement is correct?

Q4, some said thi mod will increase FC. but, some said it will decrease FC. Which statement is correct?

Q5. Titanum exhaust system will increase more in performance? How many inch exhaust piping can recommences for me? 2 bullet better than 1 bullet? My stock exhaust system can trade in?

Hope SIFU-SIFU here can share your knowledge with me.

Kazami, i really appreciate your advices.

If, i go for Open port. How many inch will you recommence to me? K&N and Blitz, which one is better? i compare with Blitz because it's maintanance free, no need re-oil like K&N and made by stainless steel, absorb cold air.

4-2-1 extractor and straight muffler is my choice now. I find that Power Zones is a good brand for extractor, it sales their exhaust piping and muffler also? Where can i get it in KL area? or any good brands and good services shops can recommend to me?

perfect bending aka mendrel bending?? Air filter should come first or Exhaust system come first?

[quote=masao343,May 28 2009, 03:11 PM]
Please read bro Kazami's reply. I'm also trying to learn from everyone. Coz read online, too many advise and its hard to decide (often makes it even harder to decide!) anyway, here's my take, please remember it's just my opinion.

actually to solve your "pick-up" the most obvious should probably be lightening your flywheel. but if you cruise at high speeds, then this may need proper consideration as the flywheel is needed to maintain inertia. also if u drive uphill a lot, better dun touch your flywheel. As for sparkplugs, forget it la. I think the gain is not significant unless you also upgrade other parts, like ignition coils, cables, etc. if only change plugs, dont expect much, might as well use normal plugs but change frequently.

Q2 and Q3: i'm especially interested in the part about exhaust muffler (because i havent change my muffler). i will very probably go for an s-flow as the back-pressure should help with low-mid RPM power. my personal opinion (not proven) is that back-pressure is needed for low-RPM range, and is bad for high-RPM as it is restrictive. it has got something to do with the "pulse" of the exhaust notes (the gas comes out in pulses), so back-pressure helps to "move" the gas out. But once you are at high-RPM, the gas needs to get out ASAP, and so a straight-flow is preferred. For me, I drive mostly city (start, stop, go) and only weekend highways so I will be opting for S-flow (low-mid RPM is important to me). I seldom press until 5k on the RPM meter for each gear. On highway also only 4k RPM and cruise. anyway, just to share that i'm also driving a 1.5L M sedan and i've changed to the following: 4-2-1 extractor (original was 4-1 and it sucked), removed catcon, replaced with swirl bullet (this one, i think u can skip bullet if u like), and changed entire piping to 1.7" size. can already feel difference (butt dyno haha) especially once i hit 3k rpm, the engine feels livelier and willing to go up to 4-5k very easily. Previously without exhaust mod, when i hit 3k RPM, the engine sounds like desperate and tired di. i not sure which made the biggest difference tho, maybe extractor, maybe larger piping (new) or maybe coz i removed catcon. take your guess.

Q1 :regarding air filter, i took shortcut as many of the bro here know i drilled holes on the ori airbox. maybe is placebo effect, but feels like engine respond better when suddenly press accelerator (can hear loud sucking noise from airbox). still using stock filter as short of $$$

Q4 I do not agree with what most ppl say about increase FC when we mod the intake and exhaust. I personally is keeping track of my mileage using simple spreadsheet so I know my FC improved after my exhaust mod. I think i can get even better FC than what i have now if i can resist not revving my engine above 3k RPM coz my exhaust note starts to sound really nice when i reach 3k RPM all the way to 4.5k RPM so i usually drag the gears til there before i up-shift (they say keep lower RPM can save fuel ma, i doing opposite). damn i love the exhaust note. Going to change muffler soon, so should get even better sound soon! i dont like loud, but i love that bassy vroom sound hehe. anyway back to story, if you are disciplined enough to keep your usual acceleration habits AFTER you mod your exhaust, you *should* be getting even better FC than before. Also another thing, bad exhaust setup = bad FC.

Q5: dunno about trade-in prices, but usually dont expect much. Keep your cat-converter tho. this one cost a lot and keep just in case u wanna sell ur car someday. can put back. if you using single pipe, den just use 1 bullet la. twin bullet only if u have twin piping, i guess. piping size, mine is 1.7", i think is fair, like bro Kazami said. dont too large, else no enuf back-pressure.

masao343, really appreciate your sincere sharing and advices.
So, what you had done is change 1.7" exhaust pipe, 4-2-1 extractor and drilled holes on the ori airbox.

As what you has mention that Bad exhaust system setup will cause Bad FC and permance. This is why, i need a Good exhaust system setup advices, i no want to headaches later.

Normally, my car is use for city drive and travel from KL to penang my hometown every 2 weeks or 3 weeks.
Mind i ask your car is 4G15 or 4G91 engine, fuel injection?

I has removed catcon, replaced with swirl bullet. trade in and add up RM30. but, felt no much improved.
i drilled holes on the ori airbox , first time i hear it. Hope can get a photo from you.

What your top speed now? increase or decrease after this mod?
Hope that can share which shop and how much you speed for this mod

This post has been edited by cwd8769: May 28 2009, 04:00 PM

[quote=kazami,May 28 2009, 03:44 PM]yeah.. powerzone extractor is good cause they did R&D and it is not cheap... almost 500 for extractor only.. piping they do have but muffler im not too sure..
for powerzone stuffs... better get from them... they located at glenmarie shah alam...
as for ur air filter, i wouldnt agree about absorb cold air... cause u need heatshields and cold air intake for it to be more effective

not too sure how to explain to u for the mendrel bending... but definitely better and cost abit more...
it is up to u... air filter is much cheaper compare to full set exhaust setup

[/quote]

Beside POWERZONE, what extractor, exhaust piping, muffler and good exhaust mod services shop can you recommence to me?
One importance thing is exhaust system mod is legal in malaysia, right?

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Added on May 28, 2009, 4:15 pm[quote=alvinz,May 28 2009, 04:10 PM]
@cwd8769, at the end of ur Q5 add this [/quote] .... like this:

bla bla bla ... large, else no enuf back-pressure.
[/quote]

[/quote]

??? don't really understand...


This post has been edited by cwd8769: May 28 2009, 04:15 PM

ZTH is a shops or websites?
I have asked in penang that days, whole exhaust system RM400++.

Should be same model with mine one, come with 4-1 extractor (SUCK) totally no pick up at all.
I no want big muffler pipe with loud sound. I prefer solid exhaust sound with good pick up and good FC.

All type of 4-2-1 extractor will be same, right? no need much notification on it?
Change air-filter and exhaust system is illegal? I hear that only engine mod is illegal unless get approved from JPJ.

As a conclusion, to solve my problem extrator 4-1 must change to 4-2-1.

Actually i decided go for s-flow, since it can perform in low-rev and silence as you has mention. But, one of the mech advice me straight muffler will be more better in pick up and top power. Then, it make me have to reconsider again.

Actually we no need border the brand of the extrator and exhaust piping. right?
How much you did this mod?

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Added on May 28, 2009, 7:33 pmthe_catacombs, thanks for your advice.

1. After change to 4-2-1 extractor will decrease the top speed as stock 4-1 extractor?
2. Open port filter will suffering at normal low speed? Drop-in with stock-in piping and box?
3. Can you propose to me whether s-flow or straight muffler and how many inch should i go for it?



This post has been edited by cwd8769: May 28 2009, 07:33 PM

Q1. 4-2-1 improve top speed also, then what will improve from 4-1?
Q2. May i know what is RAM?
Q3. Aiya, some advices is city drive better stick on s-flow muffler and less noise. inlet 1.8" how about the exhaust piping ?

wailup, thanks for your reply.
Every nech come with different comment, headache
S-Flow improve top speed??? i think should be straight muffler, right?

Just PM the price and photo to me.
I'm looking for twin loop type.

Haha, really unique muffler tip shape.
May i know muffler tip shape will effect the performance like big, small, single or twin?

OIC, if the real twin loop is better than single loop?

Why twin loop no need center bullet?

2 in 1 ??? got such parlance?

Yaya..picture pls.

It's time for me to services my car already.
If my car run up 100K milage already, consider old car?

So, 20W50, 15W50 or 15W40 is suitable for me?

Just want to share the exhaust pipe shops that i has visited today. At firts, i plan to asked for the price and the types of exhaust system that suit to my wira.

1. Taman Danau Kota, Off Jalan Genting Klang

The shop is normal, not too big and the boss is malay. He own MIT EVO IV and wira, have GEN2 and MIT EVO X doing the exhaust systme mod
in that time.

I ask the price start from 4-2-1 extractor. He encourage me don't change the ori 4-1 extractor. For my problem, better all remain the ori, only
change 2 center muffler.

I ask him, y not bullet in center?? He reply me, a lot ppl did the wrong mod and change the center muffler after that. He show me
a stack of bullet and exhaust pipes that customers leave there. a lot of famous brands also have! He add on, all wira in drag competition also
remain 4-1 extractor.

He advice me to change 2 centre muffler first, which cost me RM800. RM400 for each include installation and some piping.
He show me that GEN2 exhaust sound is nice and solid. He told me that only CAMPRO engine need change extractor. His stock wira only change
center muffler can go for 200km/h.

He add on If budget allow then change the back muffler together. I ask should go for Straight or s-flow. He said the muffler that he sell that can
store air inside, can overtake others car even in gear 5.

Beside this, i ask about the air filter and he advice me just remain the stock or ude drop in. unless your car is turbo else don't go for open-port
air filter. No matter MIVEC or V-TEC also the same.

2. Medan Makmur, Off Jalan Usahawan Setapak

The shop is big and the mech there advice me to change 4-2-1 extractor RM200++ include installation


WHY always is different advices. Make me really headache.

I think i better change a set of Hot Bits Exhaust system that tune for wira. Not need think too much.

This post has been edited by cwd8769: Jun 10 2009, 05:55 PM

Back only one muffler. But i saw EVO X also change the center muffler in his shop. He look like expert in MIT and proton car. Hope that have a lot of wira with different aftermarket exhaust system setup let me try, then i will know which one is what i looking for.

Plan to change my lubricant for my wira 1.5GLI clocked at 110k soon.

I was used 15W50 before, if i change to use 15W40 or 10W40. Do i need a engine flush?