Boost Controller

Now that you have a free-breathing turbo powerplant, you can increase the boost pressure. The stock 1G cars make about 11.1 psi of boost; 2G cars make about 14.8psi (but only 12 psi with the leaky stock CBV). You can increase this amount using a boost controller. You can go with a manual boost controller or a trick electronic controller, depending on your budget.

Next: Fuel pump upgrade.