1st step..- change the air filter, blow off and exzos pipe (3inch all over and n1 style muffler)..
2nd step- change fuel pump(more powefull pump coz u up the boost-this will make sure yur engine have enough fuel..
-fuel regulator.(to set the fuel capacity)
3nd step- EBC electronic boost controller... or maybe cheap way tulang ikan... hehe..
all mod up there are depend on yur pocket la... i think after done all up there u'll fell the differents.. trust me.. safe boost i think 1bar is enough for standard turbine that is vj20.. happy modding