Quote:
Originally Posted by rex2sx
If i amy correct you. The reason your 2.5" helped make more power was becuase it aided in cylinder SCAVENGING.
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scavenging is done by the exhaust manifold or header by timing the high and low pressure exhaust pulses with each other.
Quote:
Originally Posted by rex2sx
Pressure is like a measurement of restriction. So what youd be saying is the smaller or bigger you go, no matter what the more backpressur you will see, NO. .
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absoloutley.
any change in the diameter from the manifold flange creates a venturi
Quote:
Originally Posted by rex2sx
If you blow through a small straw and a big straw, which one flows more velocity. If you blow through the big straw you flow more AIR or VOLUME. Thats he same thing with exhuast. .
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a straw is straight and does not change diameter and also you're not going to get 100 degrees of temperature change in a straw. so that analogy is pointless.
Quote:
Originally Posted by rex2sx
The smaller pipe flows so fast it pulls the exhuast gases with it. .
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as stated above, it is the low pressure pulses that pull the gasses out.
Quote:
Originally Posted by rex2sx
The bigger you go the the slower the engine flows meaning that exhuast gases will not leave the cylinder as fast. .
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that's backpressure
Quote:
Originally Posted by rex2sx
Scavenging and backpressure are different. Big pipes hurt scavenging. Small pipes or bends gain backpressure..
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the only way for an exhaust pipe to hurt scavenging is by creating backpressure in the manifold or header and shortening the exhaust pulse width. but yes, bend in the pipe do not help.
Quote:
Originally Posted by rex2sx
Backpressure is not good.
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well that's true.
the fact is that the op already said he wanted to go forced induction of some sort. so his 3 inch will be just fine.