To be fair, if your chassis is mostly standard, you're far better off aiming for 175bhp at 15psi on a standard MAP sensor and saving for chassis mods. A standard G40 chassis with no subframe isn't so bad with a K03 turbo'd 175bhp, but if you wind the boost up to 21psi (approx 190-205bhp depending on bottom end) then you need to start thinking about how to get the power down.