Originally Posted by oscarmayer
boxter rumble comes from the firing order. i have an equil length and have the rumble.
Then you aren't truely equal length. Firing order is not the same as when the exhaust pulses hit the turbo.
In UEL headers the pulses are all staggered out hence the burble. In EL headers the pulses are all in line and in sequence. Think blowing a fan steady vs blow in hesitant pulses.