4 into 1 exhaust side pipes vs single tube pipe exhaust side pipes

[mr0077]

An empirical formula in use in 1966 was L = 120V/N, where L=tuned exhaust length, V=speed of the exhaust pulse (assumed to be 1700 f/s) and N=target RPM for peak power. This works out to a 34" runner length for 6000 RPM.
Bob, do you know what the target RPM for the Cobras was?

FWIW, a Chrysler-developed formula in that same era for tuned intakes was L=72C/N, where L=desired intake length, C=speed of intake pulse (assumed to be 1100 f/s) and N=target RPM for peak power, soooo, for the same 6000 RPM the tuned intake runners would be 13.2".

Your results may vary...

[Snakebit]

Way over my head! Anyone want to discuss the cataclism of the universe? I slept like a baby through that sermon. You can always tell who is an engineer at a party, look for the plastic pocket protector with the 20 pens and pencils sticking out of it!

[mr0077]

Snakebit, you know how to tell the extroverted engineer at the party? He's the guy looking at your shoes instead of his own...