my rb20t was also disapointing. mods are walbro 500hp fuel pump, malpassi black 2:1 regulator, hybrid intercooler kit, custom t3-t4 turbo from dyna torque, turbo back 3 inch exhaust, wolf 3d v4 tuned at rotamotive, k@n 4 inch diameter air filter. it made 189rwkw
(221hp) at 18.5 psi. ignition was said to be breaking down. since then ive closed spark plug gap and up graded to splitfire coils, now waiting to put it back on dyno. will be going to just engine managemant at moorebank, seen em do great stuff