[QUOTE]Originally posted by Strike
[B]When I was growing up I always thought of headers as a "tuned exhaust" with the implication being that more work went into maximizing performance.

 

There is a value to differences in 4 stroke headers. Taking 4 outlets and reducing them into one at the collector promotes high output horsepower, where taking the 4 outputs and reducing them into two and then into one at the collector promotes torque. I believe I read this in relation to a DC header ad.

In reading ads for V-8 headers, the length of the individual pipes effect power and rpm range for power and torque.