you need to move the air on both ends to make power efficiently. 5.5mm elements by the way. he341 with external wastegate. plus alot of other stuff... but no drugs aka nitrious or methanol.. or propane.
https://www.youtube.com/watch?v=nAVp_jUjOAc
and to the guy saying a 4bt has a disadvantage cause of its rpm. what is the highest rpm for a 6bt lol?... power driven did 7k+. hell even if it only does 4k... thats still pretty rowdy for those engines, the amount of drive pressure they can take means they they will move waaaaay more air respectively. i dunno thats apples and oranges tho not really worth a comparison cause the 4bt will SMOKE the om 60x on torq cause it has a huge mechanical advantage.

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85 300d 0m603, 717, he341, 50mm external W/G with open dump, intake manifold as well as intercooled. need to figure out a different trans before i throw more fuel at it. the 717 trans and 8" ceramic clutch are already pissed with stock elements.