Not true, it's based on all the engine build's I've seen in magazine and video where there's been dyno results', not saying that trump's other's experiences, if I didn't take that in account of others I wouldn't have started these threads, best argument so far is PRH there's more vacuum, pull etc... Which I can see per revolution but what about over time and what about when port shape, opening and closing valve event's, lsa etc.. Is taken into account.