If you are running a dual-port wastegate there are three ways to proceed with boost control.  You can simply run open loop (meaning that no ECU input is required--the boost is simply limited by the spring in the wastegate.)  You could allow the boost to be controlled by the ECU by simply controlling the dome pressure.  That is a relatively effective method requiring only a single solenoid.  But if you are going to be a purist and get the very best boost control available from your dual-port wastegate then you either need two single solenoids or, much superior, this Holley EFI High Flow Dual Solenoid Boost Control Kit.

Along with this kit you will also need some other components, including a dome pressure sensor.

Okay, we're not going to kid you--programming Holley's advanced boost control system is by no means trivial--but we are here to help walk you through it. The complexity takes into account the very individualized nature of each individual turbo setup. Different wastegate and turbocharger combinations respond differently and the Holley software allows you the most precise control, resulting in increased horsepower potential without increased risk to the engine.  Fortunately, Holley provides this really in-depth, straightforward documentation on implementing ECU boost control.  Check it out!

Not Sure? Review this product documentation before you buy!

 
User Manual
Implementing Boost Control with Holley ECU

 
Step-By-Step Example
Implementing Boost Control with Holley ECU