SS/SC Catback vs. 2.4L OEM
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From: Dirty Jerz
No they wouldn't because too big of pipes slow down the gases velocity.
the right exhaust velocity can creat a scavaging effect that "pulls" the gases when the valves open. Having the highest rate of exhaust velocity with as little back pressure as possible will flow the best. read more at the link below
http://www.nsxprime.com/FAQ/Miscella...austtheory.htm
the right exhaust velocity can creat a scavaging effect that "pulls" the gases when the valves open. Having the highest rate of exhaust velocity with as little back pressure as possible will flow the best. read more at the link below
http://www.nsxprime.com/FAQ/Miscella...austtheory.htm
:
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Joined: 09-08-06
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From: *
http://www.uucmotorwerks.com/html_pr...torquemyth.htm
Destroying a myth.
Some say that "an engine needs backpressure to work correctly." Is this true?
No. It would be more correct to say, "a perfectly stock engine that cannot adjust its fuel delivery needs backpressure to work correctly." This idea is a myth. As with all myths, however, there is a hint of fact with this one. Particularly, some people equate backpressure with torque, and others fear that too little backpressure will lead to valve burning.
Older carbureted cars couldn't compensate for extreme changes in the exhaust -- you had to enrich the carb if you put headers and freer flowing exhaust on it. Our Cobalts control fuel through the ECM/PCM and can make the adjustments automatically -- after a little driving!!!!
Destroying a myth.
Some say that "an engine needs backpressure to work correctly." Is this true?
No. It would be more correct to say, "a perfectly stock engine that cannot adjust its fuel delivery needs backpressure to work correctly." This idea is a myth. As with all myths, however, there is a hint of fact with this one. Particularly, some people equate backpressure with torque, and others fear that too little backpressure will lead to valve burning.
Older carbureted cars couldn't compensate for extreme changes in the exhaust -- you had to enrich the carb if you put headers and freer flowing exhaust on it. Our Cobalts control fuel through the ECM/PCM and can make the adjustments automatically -- after a little driving!!!!
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From: Chilliwack, BC, Canada
Back pressure is not needed..........BUT exhaust scavenging IS needed. If you run a huge pipe, then if not designed properly (and not matching the engine size) there will be little to no scavenging effect. Let me put it this way.......it is possible for a well designed properly matched smaller exhaust to be more efficient and flow more than a larger exhaust. You can't just pick the biggest exhaust out there and expect it to make the most power and torque.
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Joined: 09-08-06
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From: *
Back pressure is not needed..........BUT exhaust scavenging IS needed. If you run a huge pipe, then if not designed properly (and not matching the engine size) there will be little to no scavenging effect. Let me put it this way.......it is possible for a well designed properly matched smaller exhaust to be more efficient and flow more than a larger exhaust. You can't just pick the biggest exhaust out there and expect it to make the most power and torque.
No, I'm not comparing my car to the above! The RT system I chose works well on my 2.4L -- the idea that my 2.4L needs more backpressure is...hogwash.....
The overriding factor for car manufacturers in designing an exhaust system is sound abatement!
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