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Originally Posted by jskateborders
True... However like you said you want as much flow as possible. At a certain point, to much space available will create less flow. Basically, you want to find a happy medium in diameter(based on power, exhuast flow, ect) that will allow a higher rate of flow. In a smaller diameter, your exhaust will be traveling faster. Too small it restricts, too large, exhaust flow slows down as well. This concept changes slightly under boost. NA, you need smaller piping for lower end power, up top however, you wont suffer loss, in fact you will probally see small gains.
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No. No no no.
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However like you said you want as much flow as possible.
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Yes. Flow is good. Flow, however, is not dependent only on the speed at which the exhaust is moving through the pipe. You want to move
volume as quickly as possible.
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Too small it restricts, too large, exhaust flow slows down as well.
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No. It doesn't. Let's say you have identical cars, one with a 1.5" exhaust and one with a 3". Let's say the air in the 1.5" exhaust is moving at 30 feet per second, and the air in the 3" exhaust is moving half as quickly at 15 feet per second. Even though the air in the 3" is moving more
slowly, it still evacuates more exhaust volume because the area of the pipe's cross-section is more than twice as large.
The only thing that matters is the volume of exhaust gasses being moved. Not the straight-line velocity at which they're moving.
Think about it this way. If you have 5 seconds to get the air out of your lungs, are you going to do it faster through a coffee stirrer or a jumbo straw? Or without a straw at all? The air will be moving faster through the coffee stirrer - that is, at a higher straight-line velocity - but it'll take you a LOT more time and your cheeks are gonna be burning.
It's not rocket science.