Newer engines also have variable runner length intake manifolds, this is an OLD Harley engine I built, this is a 94 inch Harley, very old design with heads I ported on the large side for cid, it is also EFI, the blue run on the dyno is with a 8 inch long individual runner length, very gutless down low, the red line is with 22 inch runners, everything else is the same, tie both these power bands together with a Variable runner set up & you will have something that has power all over the place with a HUGE intake port on the cyl head. this is only for a 2 cyl, X the results by 4 for an 8 cyl