headers

[95rayburn]

I see on the cut away car on tv the headers have long pipes extending towards back of car is that to keep the noise behind the driver or does it gain hp?

[Matt49]

In most cases it changes the torque curve on the motor. Header extensions provide more low end torque while usually sacrificing some top end torque. Which is a good thing since pure RPMs are giving you HP at the top end.
Noise is a non-issue.

[Brian Gray]

Read smokeys book it gives some good incite on what the exhaust helps with.