To decat or to change the exhaust??

[E3ugene]

hi, i'm a newbie here, i've got a old esi with not much power..

 

i heard the decatting can bring up the power is it true??

 

my previous owner told mi that he decat the mid section liao, so i wondering should i change the whole exhaust or to decat the whole thing, pls advis, thanks in advance..

[Uplinkhack]

i thought its illegal? ok i dunno but i doubt it powers up ur vehicle..rather it reduces the power lost?

[Vblaster_w211]

Illegal and will not yield extra power unless you've changed cams and tuned for engine, thereby needing a more free flow for your exos. In fact, a loss in low end is likely for stock engine.

 

When the exos is TOO free flowing for stock engine, the dynamic fluid flow pattern of the exos gas is disrupted, leading to lower flow.

[E3ugene]

and if i change the extractor to 4-2-1 and i change the end can to a straight flow one??

 

does it make ani difference??

[Vblaster_w211]

Have you done anything to your engine? That is the key issue from my post. Only from a tuned engine with more aggressive cams (or you added turbo or SC), will you benefit from a free flowing straight thru exos.

 

If your engine is still stock (assuming it's not a performance engine), then forget it. You'll definitely lose low end.

Edited August 3, 2007 by Vblaster_w211

[Turbonetics]

Esi stock is 4-2-1,yours is 4-1?

by the way,is yours auto or manual?did you pull it until redline?

it should have a decent 1.6 litre power.

[E3ugene]

mine is a stock sohc vtec, i tried dragging to 8000+ rpm liao, but wat i wan is pick up, so i thinking should i do anithing to my exhaust system..

[E3ugene]

mine is a manual de, btw, i heard that changing to koni shocks isn't good for normal driving, is it true?

 

and does it damage the undercarraige of the car??

[Turbonetics]

you dragged your stock engine to 8,000+ rpm.

your engine can take it?

modding of exhaust does not really help in a stock NA engine.

what kind of pick up you want?

[Turbonetics]

changing shock will not damage the undercarriage.

koni should be quite okay depending on individual's preference too.

koni is not very hard in my opinion.

[Garlic]

1) Very illegal

 

2) Not much or even decrease in power if not done properly

 

3) Save the planet

 

4) Spent the $$$ on proper servicing instead

[Vblaster_w211]

Sounds like you need some performance cams + tuning. Do that along with intake and exos and you're good to go. Going to cost though...

 

Just keep to the Honda spirit of NA.

[E3ugene]

no bro, i dont tend to heavy modded my car, jus wanna gain more power will do, thus i'm soughting a cheap options to gain the power..

[Streetbumpkin]

4-2-1 + high flow cat + free flow muffler should give you the gains you looking for. Doesn't cost that much to do it in jb..

Edited August 5, 2007 by Streetbumpkin

[E3ugene]

thanks bro..

 

and do u mean changing the end muffler to a straight flow one??

[Streetbumpkin]

yes straight through...

[Wpho]

bro, decat will cause your low end to suffer. i did it and had to put it back. if your is a tc car, then the cat is the biggest obstacle to your need for a free flowing exos. for NA, and esp Auto cars, the cat will help with building that needed back pressure.

[Vblaster_w211]

Back pressure is always bad and is a misnomer when used as "back pressure is good for NA". It is about maintaining a steady pulsating dynamic flow that is important.

 

Exos flow is pulsating as the pistons fire and exhaust. At the tail end of each exos "pulse" is a slight vacuum. You'll want the "head" of the following exos pulse to be in the flow so that it rides smoothly to the slight vacuum.

 

When your exos is TOO free flowing, this flow is disrupted and you create turbulance within the exos tube. This happens when the pipe is too large for the volume of exos, typically of a normal NA. For TC engines, the exos tends to be more, hence need for the milo tin can exos design.

 

For the threadstarter, my advice is clear - you do not want to have too free flowing exos for a normal 1.6L NA engine. But if you're convinced it'll give you more power, then do be prepared for loss in low to mid end without engine tuning.