More power!

[Rb30detboi]

So I have recently bought a 30det r32 skyline, but the problem I'm having Is that with the big air intake, the 500 hp fuel pump, the 1000cc injectors, the good ecu, along side the giant fkn garrett turbo that's rated upto 800bhp pushing at 18psi with a nistune set at a 7000rpm limit is only putting out 240kw. Sure it has a good tourqe curve with the 3L block with a 25de head but shouldn't bottom line bhp be more? I'll post some photos of work done on it and photos of engine but please tell me how I can get this to the 400 kw animal it should be