tooter's manifold adventure...

[cali yaris]

Don't you want the exhaust to just get out via the back of your car rather than in the engine bay?

Remove your header and see how much power you lose with no exhaust at all. A LOT.

[Yoda]

Originally Posted by cali yaris

Remove your header and see how much power you lose with no exhaust at all. A LOT.

I can attest to that

[Shinare]

Originally Posted by cali yaris

Remove your header and see how much power you lose with no exhaust at all. A LOT.

Well that's strange, I never would have guessed that would even affect the performance of a car. So exhaust pipes on the header make the engine work better rather than having nothing there to restrict... to me that's just really weird, hehe

[CrankyOldMan]

Originally Posted by Shinare

Well that's strange, I never would have guessed that would even affect the performance of a car. So exhaust pipes on the header make the engine work better rather than having nothing there to restrict... to me that's just really weird, hehe

It's all based on the Helmholtz principle, the Bernoulli effect and fluid velocity. Lots of crazy physics and maths to explain it, but not really relevant unless you're into that sort of thing. Here's my understanding of it: escaping exhaust pulses down each tube (Helmholtz), drawing a slight vacuum on the adjacent tubes (Bernoulli). Velocity and pressure of a fluid in a tube is decreased by increasing the diameter. Decreasing the pressure means easier flow, but lower velocity and less scavenging effect...I think.