There are a couple different banks turbo kits one is wastegated and there is a older style non wastegated turbo kit. The wasted gated turbo will do about 10psi before the wastegate opens. The noneastegated turbo won't spool as quickly but will boost more as there is fuel, following the instructions on instal you turn the fuel up on your pump a 1/16 turn and it will boost about 7-9 psi but will boost more if you turn the pump up more. The wastegated turbo is better it's more responsive and the wastegate can be adjusted to let it build more boost.