The name of the game is not more boost but rather more volume of air and a reasonable intake charge temp. 35 psi from a tiny baby turbo is not close to a 100mm turbo at 8 psi. once you start going into bigger turbo and more psi then the motor will show its weaknesses. stick to bolt ons and a tune unless you rather do head work, forged rotating assembly, upgraded flowing fuel systems, upgrade transmission to handle the stress and so forthThe stock turbo in the 1.4 L is already capable of producing peak pressures of 35 psi, how high do you want to go? Any more than this, will blow your engine.