Hey I was wondering how do i hook up the External wastegate? And how do i set it to the PSI I want?

 

You hook it up by using a vaccum line that will have boost running through it. Plug that into the wastgate, when X amount of psi is seen by the wastgate it opens it up spilling out exhaust.

with a Tial wastaget you have to buy the correct spring setting.
drive the ---- out of the car till the wastegate opens, when you hear it open, (if your runnging it open, like a champ) look at the boost gauge and see where its at, lol no really dont do that i don't know your setup.
open up the wastgate and check the spring rate.