Exhaust Questions...
07-30-2002, 09:57 AM
#43
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okay...
i just read what u said up there about the 3" exhaust..
u stated that the 3" piping helps rite??
that IS true for turbo applications..
but for NA cars..
that is a different story...
atmospheric pressure do come into play..
i just read what u said up there about the 3" exhaust..
u stated that the 3" piping helps rite??
that IS true for turbo applications..
but for NA cars..
that is a different story...
atmospheric pressure do come into play..
07-30-2002, 09:59 AM
#44
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Originally posted by sinfestboy
dyno it, put on the exhaust, dyno it again. you wont lose a single lb. ft of torque, actually, you will probably gain some above 5-6 rpm
dyno it, put on the exhaust, dyno it again. you wont lose a single lb. ft of torque, actually, you will probably gain some above 5-6 rpm
07-30-2002, 11:14 AM
#46
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Back pressure reduces the power output of an engine. Greater resistance in the exhaust system requires more power from the engine to pump out the exhaust gases.
Exhaust gas remaining in the cylinder after the exhaust stroke reduces the amount of fresh air/fuel mixture than can be sucked into the engine. It simply in there taking up space. Having exhaust gas remaining in the cylinder is never a good thing.
Where primarily headers and exhaust systems come in is simply for noise reduction. But there can be a benefit. Through proper tuning (tubing diameter and length) headers through a harmonic effect can better scavenge the cylinder during the exhaust stroke in certain RPM ranges
Exhaust gas remaining in the cylinder after the exhaust stroke reduces the amount of fresh air/fuel mixture than can be sucked into the engine. It simply in there taking up space. Having exhaust gas remaining in the cylinder is never a good thing.
Where primarily headers and exhaust systems come in is simply for noise reduction. But there can be a benefit. Through proper tuning (tubing diameter and length) headers through a harmonic effect can better scavenge the cylinder during the exhaust stroke in certain RPM ranges
07-30-2002, 11:25 AM
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The best exhaust would probably be a resonance chamber bolted directly the head properly size to dampen the exhaust pulses out over its RPM range with a single pipe going to the back of the car
07-30-2002, 11:28 AM
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wow.. i can't believe the load of shit that i just read in this thread. 
i should close it because it's an embarrasment to the HAN community.
sinfestboy, weaselGSR, Paul, i'd like you to explain one thing to me.. if back pressure only hurts, and it's absolutely not needed at all, can you tell me why the nissan maxima had (maybe still has, i don't know) an exhaust with a valve that would close up at low rpm, and open up at higher rpm. with your almighty wisdom, can you please explain to me why they did that?
i should close it because it's an embarrasment to the HAN community.sinfestboy, weaselGSR, Paul, i'd like you to explain one thing to me.. if back pressure only hurts, and it's absolutely not needed at all, can you tell me why the nissan maxima had (maybe still has, i don't know) an exhaust with a valve that would close up at low rpm, and open up at higher rpm. with your almighty wisdom, can you please explain to me why they did that?
07-30-2002, 11:34 AM
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In typical Nissan fashion, the Maxima's engine is buttery-smooth at idle and pulls hard throughout the rpm band. The extra power comes from new intake and exhaust manifolds, Nissan's Variable Induction System and a new muffler that incorporates a valve that opens at 2,000 rpm to reduce exhaust back pressure.