you wont need forced induction to get 445 bhp out of a challenger. keep in mind, some dodge mags, as well as one of the big ones (C&D or MT) dyno'd the 6.1L hemi and got something like 455-460 at the crank...if the roush cars make an honest 445 at the crank, the only thing hurting the challenger will be the weight, which can be overcome with some minor work like headers.