all you need is this: MANUAL TURBO BOOST CONTROLLER CIVIC DEL SOL PRELUDE CRX | eBay

and you can turn it up to 11-12 PSI without any other changes. That is actually what it's supposed to run stock, but I'm guessing you didn't get the turbo solenoid with the swap. If the vac is hooked directly to the wastegate, it'll stop spooling at ~7psi.