The formula for primary pipe length of 4 into 2 ito 1 exhaust header is:
P = 850 X ED divided by rpm -3
Where rpm is the engine speed the exhaust is being tuned to & ED is 180 deg plus the number of deg the exhaust valve opens before BDC.
Does this stand true when compared to a crossover system as used on a GT40?
If so, then the ideal pipe length is around 27", but this conflicts with the common accepted length of 36". Can anyone shed some light on this?
P = 850 X ED divided by rpm -3
Where rpm is the engine speed the exhaust is being tuned to & ED is 180 deg plus the number of deg the exhaust valve opens before BDC.
Does this stand true when compared to a crossover system as used on a GT40?
If so, then the ideal pipe length is around 27", but this conflicts with the common accepted length of 36". Can anyone shed some light on this?