Two ways to control boost
A mechanical boost tap, or manual boost controller, is the classic open loop approach. It changes how much pressure the wastegate sees, but it can't react to anything. Boost ends up wherever the hardware lets it.
Closed loop boost control puts the ECU in charge of an electronic boost solenoid. The ECU compares measured boost to a target and adjusts the solenoid to hit it, many times a second.
Why closed loop makes more usable power
A well-tuned closed loop system gets boost up sooner in the rev range while still reaching the same peak power. That extra boost low in the rpm range is where the car actually gets driven, so it feels much stronger on the street, even though the dyno sheet's peak number might not change. It also holds a flatter, more consistent boost curve, because the ECU is correcting in real time instead of relying on a spring and a bleed.
The payoff grows with the engine. The more power and boost a setup makes, the more a direct, responsive controller helps.
Getting started
You'll need a boost control solenoid, such as the Haltech 3-port solenoid, and an ECU with boost control. Our boost control setup guide walks through the settings, and how turbo boost control works explains the hardware side. Still choosing an ECU? See which ECU is right for you.
