Originally Posted by Roswell
Not many. 10 - 15 extra bhp max.
Polished and ported cylinder head,uprated cams and a remap to set the cams up properly will get 15-20bhp possibly more,depending on the engines state.Roswell,unfortunately u will have to spend a fair few quid in order to obtain 15bhp from ur engine.
U could combine a free flowing exhaust system with another rempp and that might get u about 8-10bhp more,but after that ur into big money.
3-400 quid alone for the work on the cylinder head side of things.If u are prepared to take ur car off the road,take the cams out,send them off to be reprofiled or have uprated exchange cams sent to u on a part exchange/cash basis(A H Motorsports or Kent Cams) and fit them urself if ur not prepared to spends lots of money.
Otherwise to buy fast road cams and have the car mapped again to get the cam timing right then u are looking at £1000 for just 15+ bhp alone.
Autodelta claim up to 19bhp more for cams and a chip.
Best of luck with it.I mean that too.