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Old 07-28-2009, 12:11 AM   #1 (permalink)
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Stock V.S Aftermarket exhaust?

I was wondering if the stock manifold would be better than an aftermarket header?

I am not sure that the cost would be worth it right now. Its easily over 110 degrees out daily, so the A/C is on all the time! Showing up to work drenched is not an option.

Any input is appreciated.

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Old 07-28-2009, 12:23 AM   #2 (permalink)
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A more free flowing exhaust gives better power but less fuel effieicney, and vice versa. You could block up your exhaust lol.
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Old 07-28-2009, 12:27 AM   #3 (permalink)
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Heres a cheaper solution.

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Old 07-28-2009, 12:47 AM   #4 (permalink)
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Originally Posted by hyperyaris View Post
A more free flowing exhaust gives better power but less fuel effieicney, and vice versa. You could block up your exhaust lol.
Is that necessarily true? What I have understood is a LARGER exhaust usually hurts FE, since a larger diameter actually slows down the velocity and stagnates the flow at low revs. But keeping the factory size with a more free flowing design (headers, mandrel bent pipe, etc), shouldn't that help FE if anything? Seems like it would be part of reducing pumping losses.

Of course, any gains would be small and not worth the price of buying new parts. But if you need new parts anyway, then maybe.

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Old 07-28-2009, 05:32 PM   #5 (permalink)
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It depends on the rpm range you're trying to make best use of and how restrictive the stock exhaust is. Different diameters, lengths, changes in volume all affect exhaust pulse velocity and scavenging (narrow rpm range where exhaust pulses reflected back from volume changes in the pipes return at the right time to help pull the exhaust through an open valve).

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