chips are written as per your spec; you dont just buy a chip and it will give you 400bhp, your spec determines what power you run

there are better chips than others; but that depends on who has written the chip/ map

i run an MSD chip, and i cannot fault it

speak to stu at MSD http://www.motorsport-developments.co.uk/

depending on what your spec is, i expect he'll have a off the shelf chip

what is your spec in trying to achieve 400bhp?