this might be hard to understand but here goes base HP x (boost in BAR +1)= estimated base crank HP PSI / 14.7 = BAR to find base HP total crank HP / (boost in BAR +1) = base HP example: stock 4th gen alltrac = 190hp crank 190/((10/14.7)+1)=113 so we add full intake and exhaust which yeilds roughly 10% of you base line so now we have 113+11.3=125hp base simple enough now we add more boost (safely) and turn our turbo up to 16lbs (a little over max on stock fuel) so we have: 125*((16/14.7)+1)=261hp crank