If i ported my throttle body to a bigger diameter will it make any bhp gains also same question for the inlet manifold.

Most likely you'd lose BHP.

what ive done mate is for forthcoming tuning.

like tom says it may even loose powere, th einlet should be done by a profesional cos you need to make sure the airflow inside is perfect for max perfomance etc and the is done by flow testing etc. i looked into it and its pretty complicated stuff lol they only recomend it for big power tuning.