Exhaust system for auto tranny

desmond0318

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May 31, 2013
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I mean I change the mid 2" mid box into a 1.6" box to fix the air flow, since my whole piping is 1.6, only the muffler and mid box inlet are different.
Following theory.. I believe so, a same size piping include inlet should be the best hi flow, I`m just worry about the different after change to s-flow.
haha bro, i notice u worried too much since u start to tune almera.
If mid section in concern better first ask speedworks what's the inlet of the extractor they install for you last time to be ensure don't waste so much moneys..
 

yewly1990

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Aug 18, 2013
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haha bro, i notice u worried too much since u start to tune almera.
If mid section in concern better first ask speedworks what's the inlet of the extractor they install for you last time to be ensure don't waste so much moneys..
Ya, hell for me, I get into a wrong car, I hate the cvtc delay... killing my pick up... It is much better... If I had went into a suprima, fiesta or 208... Too bad my family fully support on japanese brand.

It was not my first car, but first step for me for car modding, and I had already spend a lot of wasted money.
Rm1550 on jian hang for a 2" piping + high flow cat + 2" mid box ( satisfied )
RM2800 on speedwork for hotbits suspension ( satisfied )
rm2200 on speedwork for hotbits full exhaust ( not happy ) they told me it was full SS!:bawling:
Rm900 on spedwork for open pod ( happy with the sound... And better top end I think:hmmmm:) better throttle response but low end loss because of it I think.
Rm400 for works drop in change to knn drop in ( regret of buying knn, it same with works )
Rm1xxx for sound proof ( best part )
Rm8xx for grounding kit ( friend diy for me with low cost and nice quality:proud: ) + vs ( change 4 times )
Rm450 for the firestorm.. ( it was totally rubbish after all. )
Still got a lot of other etc which is haven`t put into account

What I find out after all was this :
open pod was not only for manual, it usable for auto as well, just not good as manual tranny. Correct me if I`m wrong.

Impul suspension had the reason of selling rm2800.... really much comfort compare to after market suspension or spring...

Never trust in exhaust shop... plenty of them are just planning to cut my throat....

Stock engine are really hard to get high gain compare to force induction.

Almost all after market store like xxx racing, bla bla motorsport are simply bull shit as well... they just plug and play... and never tune and tested what they did...

---------- Post added at 01:07 AM ---------- 6 hour anti-bump limit - Previous post was at 01:03 AM ----------

haha bro, i notice u worried too much since u start to tune almera.
If mid section in concern better first ask speedworks what's the inlet of the extractor they install for you last time to be ensure don't waste so much moneys..
I will start on balance back the mid section, thx for all the opinion, I will back to a shop in kajang, which he tell me he could look for 1.6 inlet mid box for me... So I could start with balance the piping first... and see what happen then only made decision on doing rear muffler.
 

hex999

Known Member
Oct 27, 2011
378
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Kuala Lumpur
Can you show pictures of your entire exhaust? I removed my cats too on my cefiro a33 2.0, maintain original piping size 2.0. Had a big centre bullet and rear 1 in 2 out mufler. After the mod, FC improve tremendously but felt a bit sluggish on low RPM, I was assume i lack of backpressure, after doing some research, i read up about some poorly designed bullets can cause more back pressure and choke the engine, so I gave it a try and removed my middle centre box to a straight pipe, and both lower and higher end torque improved even more, well the sound got much louder though :D

For your case, I personally think a 2 inch midbox is too huge for your engine HP,
http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

if you cant find a proper 1.6 mid box, how about you try a straight pipe 1.6 and replace the midbox if you cant find a proper one.
and use a 1.6 S flow mufler. Since you removed your cats, you need back pressure, you will lose a bit of high end power but you gotta remember which power band are you always using? If you were using a manual tranny, would recommend straight flow no doubt,

Last time when modding my old perdana v6 manual, I was using a full 2.3 inch 6-2-1 pipe and a 2.5 inch straight flow mufler, a sifu suggested to reduced the diameter of my mufler, in the end changed to 2.3 inch straight flow mufler and got a slightly better powerband(power comes slightly earlier, i was shock that a small change made a big difference) NA engines are very sensitive to piping diameter, so I suggest you to keep your entire piping to 1.6, not rojak. Im no expert and my advice might be wrong.
 

yewly1990

Known Member
Thread starter
Aug 18, 2013
156
28
528
Kuala Lumpur
Can you show pictures of your entire exhaust? I removed my cats too on my cefiro a33 2.0, maintain original piping size 2.0. Had a big centre bullet and rear 1 in 2 out mufler. After the mod, FC improve tremendously but felt a bit sluggish on low RPM, I was assume i lack of backpressure, after doing some research, i read up about some poorly designed bullets can cause more back pressure and choke the engine, so I gave it a try and removed my middle centre box to a straight pipe, and both lower and higher end torque improved even more, well the sound got much louder though :D

For your case, I personally think a 2 inch midbox is too huge for your engine HP,
http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

if you cant find a proper 1.6 mid box, how about you try a straight pipe 1.6 and replace the midbox if you cant find a proper one.
and use a 1.6 S flow mufler. Since you removed your cats, you need back pressure, you will lose a bit of high end power but you gotta remember which power band are you always using? If you were using a manual tranny, would recommend straight flow no doubt,

Last time when modding my old perdana v6 manual, I was using a full 2.3 inch 6-2-1 pipe and a 2.5 inch straight flow mufler, a sifu suggested to reduced the diameter of my mufler, in the end changed to 2.3 inch straight flow mufler and got a slightly better powerband(power comes slightly earlier, i was shock that a small change made a big difference) NA engines are very sensitive to piping diameter, so I suggest you to keep your entire piping to 1.6, not rojak. Im no expert and my advice might be wrong.
I give u a photo tomorrow, I will consider with your advice.

I was mistaken with the muffler part last time, I tot muffler only play role in changing exhaust sound, I tot the inlet piping does`t makes any different on performance.

I will go for exhaust shop look for 1.6" to replace my current resonator, and maintain same pipe size until rear muffler part, just wondering could the shop get me a 1.6 muffler.

I will get back here for the result after replacing my mid section.

I was wondering last time why Jianhang giving me 2.0 piping but I`m still maintain a good back pressure, it is all because of the cat he given me...

I was brainwash by some people which telling me that every car had to decat, because it restrict too much...
 

desmond0318

Known Member
May 31, 2013
467
48
528
Kuala Lumpur
Ya, hell for me, I get into a wrong car, I hate the cvtc delay... killing my pick up... It is much better... If I had went into a suprima, fiesta or 208... Too bad my family fully support on japanese brand.

It was not my first car, but first step for me for car modding, and I had already spend a lot of wasted money.
Rm1550 on jian hang for a 2" piping + high flow cat + 2" mid box ( satisfied )
RM2800 on speedwork for hotbits suspension ( satisfied )
rm2200 on speedwork for hotbits full exhaust ( not happy ) they told me it was full SS!:bawling:
Rm900 on spedwork for open pod ( happy with the sound... And better top end I think:hmmmm:) better throttle response but low end loss because of it I think.
Rm400 for works drop in change to knn drop in ( regret of buying knn, it same with works )
Rm1xxx for sound proof ( best part )
Rm8xx for grounding kit ( friend diy for me with low cost and nice quality:proud: ) + vs ( change 4 times )
Rm450 for the firestorm.. ( it was totally rubbish after all. )
Still got a lot of other etc which is haven`t put into account

What I find out after all was this :
open pod was not only for manual, it usable for auto as well, just not good as manual tranny. Correct me if I`m wrong.

Impul suspension had the reason of selling rm2800.... really much comfort compare to after market suspension or spring...

Never trust in exhaust shop... plenty of them are just planning to cut my throat....

Stock engine are really hard to get high gain compare to force induction.

Almost all after market store like xxx racing, bla bla motorsport are simply bull shit as well... they just plug and play... and never tune and tested what they did...

---------- Post added at 01:07 AM ---------- 6 hour anti-bump limit - Previous post was at 01:03 AM ----------



I will start on balance back the mid section, thx for all the opinion, I will back to a shop in kajang, which he tell me he could look for 1.6 inlet mid box for me... So I could start with balance the piping first... and see what happen then only made decision on doing rear muffler.
The lack off throttle response might be the drive by wire TB, these days car's have so many electrons. Not much things to tune by hand like those crabs ^_^
I thought cvtc suppose to be better than cvt, when i worked at tan chong last time the slyphy came out with this cvt is like what the hell like 1 gear run all along our driving journey and sluggish feeling.
But look at the bright side Almera damn steady going thru rough road surface..

---------- Post added at 02:23 AM ---------- 6 hour anti-bump limit - Previous post was at 02:11 AM ----------

I give u a photo tomorrow, I will consider with your advice.

I was mistaken with the muffler part last time, I tot muffler only play role in changing exhaust sound, I tot the inlet piping does`t makes any different on performance.

I will go for exhaust shop look for 1.6" to replace my current resonator, and maintain same pipe size until rear muffler part, just wondering could the shop get me a 1.6 muffler.

I will get back here for the result after replacing my mid section.

I was wondering last time why Jianhang giving me 2.0 piping but I`m still maintain a good back pressure, it is all because of the cat he given me...

I was brainwash by some people which telling me that every car had to decat, because it restrict too much...
If all car decat than now KL's haze like beijing already, decat is for low budget ppl like me :p
Saw a post at mudah they do custom order, but not sure the pricing fair or not.
New custom made centre midbox 1.6inch inlet - Car Accessories & Parts for sale Kuala Lumpur - Mudah.my
 

Izso

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Mar 28, 2004
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Uh.. Yewly - I didn't know your exhaust was so mixed up. The piping size is important as it affects the speed of the exhaust gases going out and how much scavenging you'll get. I suspect you'll do better if everything was standard 1.6" or everything was 2". Either way I think that mid long resonator has to go. 2" inlet from a 1.6" is too much la. You should get everything the same diameter in and out.
 

peeche

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Senior Member
May 16, 2006
395
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Sin City, MY
Ya, hell for me, I get into a wrong car, I hate the cvtc delay... killing my pick up... It is much better... If I had went into a suprima, fiesta or 208... Too bad my family fully support on japanese brand.

It was not my first car, but first step for me for car modding, and I had already spend a lot of wasted money.
Rm1550 on jian hang for a 2" piping + high flow cat + 2" mid box ( satisfied )
RM2800 on speedwork for hotbits suspension ( satisfied )
rm2200 on speedwork for hotbits full exhaust ( not happy ) they told me it was full SS!:bawling:
Rm900 on spedwork for open pod ( happy with the sound... And better top end I think:hmmmm:) better throttle response but low end loss because of it I think.
Rm400 for works drop in change to knn drop in ( regret of buying knn, it same with works )
Rm1xxx for sound proof ( best part )
Rm8xx for grounding kit ( friend diy for me with low cost and nice quality:proud: ) + vs ( change 4 times )
Rm450 for the firestorm.. ( it was totally rubbish after all. )
Still got a lot of other etc which is haven`t put into account

What I find out after all was this :
open pod was not only for manual, it usable for auto as well, just not good as manual tranny. Correct me if I`m wrong.

Impul suspension had the reason of selling rm2800.... really much comfort compare to after market suspension or spring...

Never trust in exhaust shop... plenty of them are just planning to cut my throat....

Stock engine are really hard to get high gain compare to force induction.

Almost all after market store like xxx racing, bla bla motorsport are simply bull shit as well... they just plug and play... and never tune and tested what they did...

---------- Post added at 01:07 AM ---------- 6 hour anti-bump limit - Previous post was at 01:03 AM ----------



I will start on balance back the mid section, thx for all the opinion, I will back to a shop in kajang, which he tell me he could look for 1.6 inlet mid box for me... So I could start with balance the piping first... and see what happen then only made decision on doing rear muffler.
i already got 220whp whooping from 120whp with that amount of money.. hahaha

---------- Post added at 07:41 AM ---------- 6 hour anti-bump limit - Previous post was at 07:37 AM ----------

lesson learned.. just let the stock engine untouched and enjoy the good fc. unless you want to BOT or transplant the engine. :burnout:
 

vr2turbo

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i already got 220whp whooping from 120whp with that amount of money.. hahaha

---------- Post added at 07:41 AM ---------- 6 hour anti-bump limit - Previous post was at 07:37 AM ----------

lesson learned.. just let the stock engine untouched and enjoy the good fc. unless you want to BOT or transplant the engine. :burnout:
Yup, I use almost same amount and got 200bhp transplant, plus suspension and brakes upgrade...:driver:
 

yewly1990

Known Member
Thread starter
Aug 18, 2013
156
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Kuala Lumpur
Uh.. Yewly - I didn't know your exhaust was so mixed up. The piping size is important as it affects the speed of the exhaust gases going out and how much scavenging you'll get. I suspect you'll do better if everything was standard 1.6" or everything was 2". Either way I think that mid long resonator has to go. 2" inlet from a 1.6" is too much la. You should get everything the same diameter in and out.
Erm, ya, I dunno the inlet size will effect the system.

---------- Post added at 08:59 AM ---------- 6 hour anti-bump limit - Previous post was at 08:56 AM ----------

i already got 220whp whooping from 120whp with that amount of money.. hahaha

---------- Post added at 07:41 AM ---------- 6 hour anti-bump limit - Previous post was at 07:37 AM ----------

lesson learned.. just let the stock engine untouched and enjoy the good fc. unless you want to BOT or transplant the engine. :burnout:
I paid for the lesson, no pain no gain what

---------- Post added at 09:07 AM ---------- 6 hour anti-bump limit - Previous post was at 08:59 AM ----------

Yup, I use almost same amount and got 200bhp transplant, plus suspension and brakes upgrade...:driver:
Hmm.... Everyone have their sense on spending their money, I actually spend my money main reason to understand it, and to get some upgrade of course.
Soon I will go for the engine tuning part, for piston, acp, lcp, manifold and so on. But remain on na... I`m not really into force induction atm for this car.
 

6UE5t

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Oct 8, 2010
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This maybe can help you to estimate the piping diameter you'd need.
Exhaust Size Calculator
https://www.facebook.com/notes/1947...ize-and-exhaust-pipe-diameter/563111347061660

Based on the above, with the power of the Almera in more or less stock setup, you only need 1.6'-1.7' pipe all the way. Since you already have a 1.75' at the back and you'd want to have room to accommodate future power improvement of your engine, then like I said before, get replace the 2' mid section with a 1.75' one to make it the same with your rear muffler.
 

hex999

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Oct 27, 2011
378
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Kuala Lumpur
My suggestion since your into modding and you dont mind spending some money. Change your auto tranny to a manual tranny. Than only mod your exhaust to a 1.7 diameter to the least back pressure setup. Straight pipe+ straight flow exhaust. Not sure how much would it cost though if half cut.

Or change to this half cut.. not sure if its plug and play
http://m.mudah.my/list?q=almera+manual&ca=9_3_s&e=0&sa=&cg=1060&female_subcat=&o=0
 
Last edited:

yewly1990

Known Member
Thread starter
Aug 18, 2013
156
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Kuala Lumpur
This maybe can help you to estimate the piping diameter you'd need.
Exhaust Size Calculator
https://www.facebook.com/notes/1947...ize-and-exhaust-pipe-diameter/563111347061660

Based on the above, with the power of the Almera in more or less stock setup, you only need 1.6'-1.7' pipe all the way. Since you already have a 1.75' at the back and you'd want to have room to accommodate future power improvement of your engine, then like I said before, get replace the 2' mid section with a 1.75' one to make it the same with your rear muffler.
Hmm, I went for exhaust in kajang today, he tell me my mid box should inlet 1.6", it just look big at outside, and they suggest to change rear muffler to s-flow to get more back pressure, since I got no cat. I will double check soon for the inlet size =\
 

TitanRev

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Actually, your Almera is light mod...for me I can have a better exhaust less than 1K if you know what you need to do..FOr me I only swap the headers, replace the stock mid box and swap out the stock S flow with a high flow S flow done....no need to add so many of those extra what what bullet or this and that....
 

vr2turbo

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Hmm.... Everyone have their sense on spending their money, I actually spend my money main reason to understand it, and to get some upgrade of course.
Soon I will go for the engine tuning part, for piston, acp, lcp, manifold and so on. But remain on na... I`m not really into force induction atm for this car.
Yup, I started out on NA too, but not so extensive mod like you. Spend a little here and there then found the improvement is a little here and there too. So decide to go forced induction and never looked back....:driver:
 

peeche

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ermmm.. but this is the use of internet nowadays. google and research first to avoid being cheat or make mistakes. i took a whole week just to gather information about windows tinting film before i bought it a nearly months before i go through engine mods. i try to understand every pro and cons.

for n/a just for geli2 setup, maybe you can visit reputable exhaust shop such as Jaafar, Everco, Ah heng, Panjang or Xcess Work for full custom exhaust system. then add drop in / open pod filter. rm2-3k already ngam. add another rm1.5-2k for piggyback management. :burnout:
 

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