Yeah that's the trade off... the stock turbo tuned well can be huge down low, which just wont happen on a low comp motor with a 42 unfortunately. The perfect combo wont come round on the first set-up though, If your seriously into it prepare to try some differnt combos, I like to start off big and work backwards, that way you can find your top end goal, and try to bring up the lower/mid range through exhaust housings/manifolds/piping/exhaust ect... and tuning, and tuning, and tuning