[oldman]

Originally Posted by gmcvt

Im curious about this also. It seems on the surface this might be a "trade off". But if it makes the same power then clearly it is not. Which then begs the question, why do the others choose equal length?

because somewhere back in time somebody told them a story of the waves merging at the collector and creating a negative pressure wave to help evacuate the gass from the other tubes AND so goes the story if the tubes are equal length meaning the exhaust pulses would arrive evenly spaced you would get further benefits. Turns out the story is true on inline engines and flatplane 90 degree V8, but any NORMAL v8 that you know of the pulse waves occur at all different times, hence the 1965 289 Mustang went to a tri-Y and so did GM in the LT1 for the Camaro only. The old OHV Ford 5.0 went to shorty unequal length. So yep equal length headers work just not on normal 90 degree V8 unless you want to pass tubes under or over the engine.

This pulsation overlap is so bad that the GT500 went to a supercharger vs twin turbo and it was because the engine is normal crank V8.

Here is a barrel of snakes header for the GT40 in an effort to create an equal pressure wave header:
https://www.google.com/search?q=ford...BKAVFwq5ek8hM:



tri-y by Kooks:https://www.corvetteforum.com/forums...-into-1-s.html