hey people ive been doing to car research n i just wanted to see if there right?

ive been reading a book about honda/acura engine performance n its saying that the faster the exhaust gases leave the car, meaning less back pressure build up is better cuz the engine doesnt havet to work as hard to push the gases out.

so i figured that havin a dual exh system would be a good idea but a bit concerned about the noise lvl

 

LOL!!!!


no is not better it creates more back pressure

 

actually dual exhaust would create less back pressure. but if you dont have enough back pressure, you will lose power. usually cars with dual exhaust have a larger displacement engine and create more power naturally. you dont need a larger exhaust system unless you have alot of motor work or a forced induction system.

 

if you made a custom header/s with two outlets i would go for it.

 

This is a concept I brought up a while ago, and there is more to it than most people who immediately poke fun actually realise. In order to maintain exhaust gas velocity while minimising restriction and back-pressure, a properly designed dual setup could potentially be beneficial from a performance perspective, though it could also present certain drawbacks. Here is an older thread discussing the topic: https://honda-tech.com/zerothread?id=734029

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by na+b18c_hatch &raquo;</TD></TR><TR><TD CLASS="quote">actually dual exhaust would create less back pressure. but if you dont have enough back pressure, you will lose power. usually cars with dual exhaust have a larger displacement engine and create more power naturally. you dont need a larger exhaust system unless you have alot of motor work or a forced induction system.</TD></TR></TABLE>

Incorrect. Do some research and stop talking.

 

Contrary to common popular belief, a larger exhaust does not always result in better engine performance. There are situations where an engine could loose low-end torque from "too little" backpressure. I know it seems counter-intuitive to think that an engine actually needs a certain amount of backpressure but here's why. Most engines are set up from the factory for a certain level of backpressure. Changing the exhaust can create a situation where the cam has too much overlap for the RPM range it's being driven in. In that case, the incoming fuel/air will come in the intake valve, only to have part of it sucked straight out the exhaust valve without getting burned! Obviously, engine power will suffer if it doesn't get a full fuel charge to burn. Proper backpressure will prevent this. So will choosing a more appropriate cam for your RPM range, however.

There is another, more complex reason why 5" pipes on a normal sized naturally aspirated engine won't work. It isn't that the engine needs more backpressure, it's that static pressure is only half the equation. The equation for the "equivalent" pressure at the exhaust port is P-pv^2, the static pressure minus the exhaust density times the square of the exhaust velocity at the port. A 5" pipe may see a slight reduction in static pressure but will kill off the velocity making it harder to push the exhaust out. Some tuned header systems can make the exhaust velocity high enough that the engine effectively has a lower amount of backpressure than the atmospheric pressure! This is known as exhaust scavenging and is what separates good headers from bad ones.

In the case of a turbocharged car, everything is different. They can run a huge exhaust pipe, like the HKS 5" pipes and see a performance gain rather than loss. The reason is the turbine. The exhaust coming out of the cylinders only sees the velocity going into the turbine. The velocity drop across the turbine doesn’t effect flow. On a turbocharged engine, there is no need to worry about the exhaust velocity downstream of the turbine. The size of the header primary tubes and collector, or the exhaust manifold design, still plays a larger role in determining exhaust velocity, but the pipes downstream of the turbo are a lot less important.

As for the turbo itself, you want to maximize the pressure (and temperature) difference across the turbine for the highest efficiency. A low velocity of the gasses exiting the turbine won't make it any less efficient; in fact, it can theoretically improve the efficiency of the turbine. So the exhaust on a turbocharged car can be designed to minimize static pressure, without concern for the exhaust velocity.

 

man i feel like im in school 0_0

ha just kidding man great information

 

no, not for you.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93eg2james &raquo;</TD></TR><TR><TD CLASS="quote">Contrary to common popular belief, a larger exhaust does not always result in better engine performance. There are situations where an engine could loose low-end torque from "too little" backpressure. I know it seems counter-intuitive to think that an engine actually needs a certain amount of backpressure but here's why. Most engines are set up from the factory for a certain level of backpressure. Changing the exhaust can create a situation where the cam has too much overlap for the RPM range it's being driven in. In that case, the incoming fuel/air will come in the intake valve, only to have part of it sucked straight out the exhaust valve without getting burned! Obviously, engine power will suffer if it doesn't get a full fuel charge to burn. Proper backpressure will prevent this. So will choosing a more appropriate cam for your RPM range, however.

There is another, more complex reason why 5" pipes on a normal sized naturally aspirated engine won't work. It isn't that the engine needs more backpressure, it's that static pressure is only half the equation. The equation for the "equivalent" pressure at the exhaust port is P-pv^2, the static pressure minus the exhaust density times the square of the exhaust velocity at the port. A 5" pipe may see a slight reduction in static pressure but will kill off the velocity making it harder to push the exhaust out. Some tuned header systems can make the exhaust velocity high enough that the engine effectively has a lower amount of backpressure than the atmospheric pressure! This is known as exhaust scavenging and is what separates good headers from bad ones.

In the case of a turbocharged car, everything is different. They can run a huge exhaust pipe, like the HKS 5" pipes and see a performance gain rather than loss. The reason is the turbine. The exhaust coming out of the cylinders only sees the velocity going into the turbine. The velocity drop across the turbine doesn’t effect flow. On a turbocharged engine, there is no need to worry about the exhaust velocity downstream of the turbine. The size of the header primary tubes and collector, or the exhaust manifold design, still plays a larger role in determining exhaust velocity, but the pipes downstream of the turbo are a lot less important.

As for the turbo itself, you want to maximize the pressure (and temperature) difference across the turbine for the highest efficiency. A low velocity of the gasses exiting the turbine won't make it any less efficient; in fact, it can theoretically improve the efficiency of the turbine. So the exhaust on a turbocharged car can be designed to minimize static pressure, without concern for the exhaust velocity.</TD></TR></TABLE>just what i was thinking

 

ah makes sense now, but ill think ill play it safe for now n run on a single exhaust.

still decidin my choices from a apexi n1 or apexi gt ( same thing as the n1 i think still doing the research on that) n a tanabe super madellion or the ultra.

then when i boost my d16y8 then ill just get a y-pipe n add the second exhaust. good or bad plan?

btw if any of u guys have those exhaust system i would like to hear from you experience with them ty

 

1. Go for apexi, good exhaust & brand.
2. Don't do dual-exhaust unless you really want to. After all, It's your car and if you want it, do it if it makes you happy/

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by na+b18c_hatch &raquo;</TD></TR><TR><TD CLASS="quote">actually dual exhaust would create less back pressure. but if you dont have enough back pressure, you will lose power. usually cars with dual exhaust have a larger displacement engine and create more power naturally. you dont need a larger exhaust system unless you have alot of motor work or a forced induction system.</TD></TR></TABLE>


O RLY ?!?!? S2000 F20. 2Litre motor.-dual exaust
Prelude H22a4 2.2 Litre motor. - single exaust

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Archidictus &raquo;</TD></TR><TR><TD CLASS="quote">

Incorrect. Do some research and stop talking.</TD></TR></TABLE>


I wouldn't throw it on my car, but in theory a true dual exhaust (even though our cars only have one exhaust bank) would create less backpressure and would flow better than a single exhaust.

 

Spend your money elsewhere. Dual exhaust also don't alway look good on cars that only came with a single end pipe!

 

i know i read somewhere that there is another theory, that after you get the exhaust gasses flowing, the bigger exhaust pipes do help on smaller engines.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Iboot &raquo;</TD></TR><TR><TD CLASS="quote">O RLY ?!?!? S2000 F20. 2Litre motor.-dual exaust
Prelude H22a4 2.2 Litre motor. - single exaust</TD></TR></TABLE>


Call me crazy, but if I remember correctly the S2K does have dual exhaust...but that's just from the cat-back (kinda like a reverse y-pipe).

So, it's not a TRUE dual exhaust like Chevy's, Ford's, etc.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JKov240 &raquo;</TD></TR><TR><TD CLASS="quote">


Call me crazy, but if I remember correctly the S2K does have dual exhaust...but that's just from the cat-back (kinda like a reverse y-pipe).

So, it's not a TRUE dual exhaust like Chevy's, Ford's, etc.
</TD></TR></TABLE>

Correct. The S2000's stock "dual" exhaust is essentially cosmetic.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Iboot &raquo;</TD></TR><TR><TD CLASS="quote">


O RLY ?!?!? S2000 F20. 2Litre motor.-dual exaust
Prelude H22a4 2.2 Litre motor. - single exaust</TD></TR></TABLE>

exactly why i said USUALLY. alot of dual exhausts are impractical for the cars on which they're installed.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by illusionz xx &raquo;</TD></TR><TR><TD CLASS="quote">i know i read somewhere that there is another theory, that after you get the exhaust gasses flowing, the bigger exhaust pipes do help on smaller engines.</TD></TR></TABLE>

too big a pipe and the exhaust gases will have turbulence. too small and they become restricted. you have to find a compromise in size that gives you what you're looking for.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JKov240 &raquo;</TD></TR><TR><TD CLASS="quote">


Call me crazy, but if I remember correctly the S2K does have dual exhaust...but that's just from the cat-back (kinda like a reverse y-pipe).

So, it's not a TRUE dual exhaust like Chevy's, Ford's, etc.
</TD></TR></TABLE>

It's as "true" of a dual exaust as it gets noob. Fords And Chevy's have duals most of the time because they are V type motors, which have 2 headers. And it's simply easyer to run a sepparate exaust for each header rather then join them and Make a huge single exaust. The civic forum is so god damn noob. People ask some of the dumbest questions here.

You guys wanna gain some knowlege, hop into the Prelude section. Revi and other lads will rip you a new a$$hole.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Iboot &raquo;</TD></TR><TR><TD CLASS="quote">It's as "true" of a dual exaust as it gets</TD></TR></TABLE>

No, it isn't. If you want to see a "true" inline-4 dual exhaust setup, check out an E30 M3.

By the way, the "noob" you directed your post towards has been a member quite a bit longer than you have. It's possible to post and discuss things without resorting to name calling.

 

Why, cuz they got 2 header pipes running from the motor to a sepparate exaust. SAME **** !

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Iboot &raquo;</TD></TR><TR><TD CLASS="quote">Why, cuz they got 2 header pipes running from the motor to a sepparate exaust.</TD></TR></TABLE>

Yes, that is precisely why.

There is a difference between a true dual exhaust and an exhaust that simply splits into two before the rear bumper. That is the point JKov240 was attempting to make.

 

I could care less how many post he has under his belt, or when he joined. That post # tells me that he either has no life and spends his days on H-T. or he doesn't know **** and posts 35 times about how to drain your oil and the propper method on bleeding your brakes. It's funny how some people completely disregard facts and base everything on peoples post count isn't it ?