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Catcon!


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#21
slushmatic

Posted 04 April 2011 - 06:23 AM

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QUOTE (jasondotcom @ Apr 3 2011, 01:17 AM) <{POST_SNAPBACK}>
with the catcon in place i can tell you, its a hell lots of difference! plus, persona's stock manifold internal design is very small and restrictive. but then the lost in performance i believe was due to the restrictive catcon unit itself.

Agreed - removal of the catcon itself will have by far the biggest effect. Just replacing the catcon without any changes to the manifold would still show a good improvement.
Reducing backpressure further down the exhaust system will also yield positive results - if to a lesser degree usually.

My point was that although custom-made extractors/headers work very well and look great, it's also true that most modern standard-fit cast manifolds flow alot more efficiently than they first look, often performing better than expected. A nice bonus is that they're a much cheaper option of course.

'Do average things - get average results'

#22
kasut

Posted 04 April 2011 - 11:26 PM

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This is interesting, what if i replace the stock cat-con with the high flow cat-con? any significant difference? Do they sell it here in Malaysia?

Or i just remove the cat-con & connect it with something else, what would be the best? with all else remains the same,will the engine be quieter?



#23
jasondotcom

Posted 05 April 2011 - 09:42 AM

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QUOTE (slushmatic @ Apr 4 2011, 06:23 AM) <{POST_SNAPBACK}>
Agreed - removal of the catcon itself will have by far the biggest effect. Just replacing the catcon without any changes to the manifold would still show a good improvement.
Reducing backpressure further down the exhaust system will also yield positive results - if to a lesser degree usually.

My point was that although custom-made extractors/headers work very well and look great, it's also true that most modern standard-fit cast manifolds flow alot more efficiently than they first look, often performing better than expected. A nice bonus is that they're a much cheaper option of course.


smile_thumbup.gif

 


#24
slushmatic

Posted 05 April 2011 - 11:04 PM

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QUOTE (kasut @ Apr 4 2011, 11:26 PM) <{POST_SNAPBACK}>
This is interesting, what if i replace the stock cat-con with the high flow cat-con? any significant difference? Do they sell it here in Malaysia?

Or i just remove the cat-con & connect it with something else, what would be the best? with all else remains the same,will the engine be quieter?


Replacing the standard catcon with a high-flow version will certainly help and has the bonus that it avoids any problems with the annual government car inspections that happen in most countries. Providing there is enough room to fit it, it is a fairly simple/cheap option. Normaly makes either minimal or no difference at all to noise levels.

More popular in the UK is to fit what is often called a 'catcon bypass' section of pipe. This name is slightly misleading - it dos'nt actualy 'bypass' anything, rather it is a section of exhaust pipe/s that directly replaces a removed standard catcon. Usually a socket to take the lambda/oxygen sensor has to be included in the pipe. Even with retaining the standard manifold and exhaust, the results are always good. Any differences in noise levels are harder to predict, but will be modest if the standard exhaust/silencers/mufflers are retained.

Advantages are that it is simple, quite cheap, light in weight, easier to change-over and less restrictive than any catcon. Downside is that it will fail a 'visual' government inspection, so has to be changed-over at test time. However, it has been shown that most engines that are in good condition/well maintained can still pass the actual exhaust emmisions tests without the catcon, (certainly upto Euro/Step3 levels) - depending on how harsh the local set limits are in any particular country.
'Do average things - get average results'

#25
kasut

Posted 06 April 2011 - 12:01 AM

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The 'bypass' is a good option, as im thinking of something that can be easily changed in place of the cat-con. i prefer to bolt-on rather than weld. it sounds simple enough to try, hope to get decent result.

#26
ahk

Posted 06 April 2011 - 01:10 PM

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sorry still not understand.

when installing 4-2-1 extractor does the CAT been removed as well?

or which one is better?
install 4-2-1 or just remove CAT?

#27
chrislyv

Posted 07 April 2011 - 12:46 PM

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QUOTE (ahk @ Apr 6 2011, 01:10 PM) <{POST_SNAPBACK}>
sorry still not understand.

when installing 4-2-1 extractor does the CAT been removed as well?

or which one is better?
install 4-2-1 or just remove CAT?


the ori CAT + exhaust header/manifold will be removed when u install an aft-mkt 4-2-1 extractor..
from my point of view & experience, install 4-2-1 is much better than just removing the CAT..
since the persona's CAT is located at the exhaudst manifold, myself jst replace the whole thing with an 4-2-1 extractor..

 


#28
ahk

Posted 07 April 2011 - 02:26 PM

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thanks for explaining. Now i understand better.

But still wondering my honda accord auto yr 94 has the CAT?

any idea roughly how much for me to change to 4-2-1?

#29
ahk

Posted 13 April 2011 - 08:15 AM

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My car the CAT not inside the manifold. It is at the central area of the exhaust system. So, i will remove my CAT next week replaced it with a silencer. See if it give me better performance and hope better FC too !!

This is cheaper option. Later stage only think of changing to 4-2-1 extractor.

#30
slushmatic

Posted 13 April 2011 - 02:52 PM

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QUOTE (ahk @ Apr 13 2011, 08:15 AM) <{POST_SNAPBACK}>
My car the CAT not inside the manifold. It is at the central area of the exhaust system. So, i will remove my CAT next week replaced it with a silencer. See if it give me better performance and hope better FC too !!

This is cheaper option. Later stage only think of changing to 4-2-1 extractor.

The CAT/catcon is not inside the manifold, (this can be misleading) but is bolted directly to it. This is the best place for a catcon, as it needs to be hot to work correctly. Having it attached to the exhaust manifold means it warms-up faster and works properly more quickly and so is prefferable to it being fitted further down the exhaust system.

Your plan to replace the catcon with a silencer could work well, but if the silencer used is too restrictive, there will be no improvements.
Replacing your catcon with a section of plain exhaust pipe, (at least the same diameter as the original pipe either side) should be no more expensive and will yield good results, but could prove to be noisier - possibly too much so.
'Suck it and see' is the only answer, unless someone else has already done the same thing to an identical car.

Good luck with this! Let us know how it goes wink.gif
'Do average things - get average results'