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FAQ: Diverter Valve
This straightforward yet impactful upgrade has gained much attention for eliminating boost leaks and improving drivability. As its popularity grows, so do the questions about how it works, what it does, and why it’s worth considering. In this FAQ, we’re addressing your most common questions, breaking down the details, and helping you get the most out of this game-changing modification. Let’s dive in!
Question #1 - What is a diverter valve?
A diverter valve is a key component in turbocharged engines that relieves boost pressure when the throttle closes. When you close the throttle under boost, the built-up pressure needs a place to go. The diverter valve opens to divert the boost around the turbo, preventing it from coming to a sudden stop. Without this part, the turbo would almost stop spinning, negatively affecting throttle response. Diverter valves can be either electronic or mechanical, depending on the design.
Question #2 - What is the difference between an electronic and mechanical diverter valve?
Electronic Diverter Valves: OEM diverter valves are typically electronic and controlled by the ECU. These operate as an on/off switch, opening and closing based on maps programmed in the ECU. While effective, the abrupt nature of their operation can impact drivability.
Mechanical Diverter Valves: Aftermarket mechanical diverter valves, like the one we offer, operate using vacuum pressure from the intake manifold. This design ensures smoother transitions when opening and closing the valve, improving drivability. Unlike electronic valves, mechanical ones adjust proportionally to how you move the throttle, providing a more seamless driving experience.
Question #3 - What does a diverter valve do?
The primary role of a diverter valve is to maintain drivability and eliminate boost leaks. Many factory diverter valves have plastic seals and suboptimal designs that allow boost pressure to escape, reducing power and forcing the turbo to work harder. Our upgraded diverter valves solve these issues, enhancing performance by:
- Eliminating boost leaks
- Reducing the strain on your turbo
- Providing smoother transitions for better drivability
Question #4 - Is there a difference between a blow off valve and a diverter valve?
People often use the terms "blowoff valve" and "diverter valve" interchangeably. However, there is a technical distinction:
- Blowoff Valve: Vents boost pressure to the atmosphere, creating the iconic hissing sound. However, this can cause issues because the ECU calculates the air entering the engine, and venting it outside can result in a rich air-fuel mixture.
- Diverter Valve: Recirculates boost pressure back into the turbo system, maintaining smooth operation and avoiding the issues caused by venting to the atmosphere.
Question #5 - Why is venting to atmosphere bad?
When boost pressure is vented to the atmosphere, the ECU cannot account for the loss of air, causing the engine to run rich. This can result in stumbling, reduced efficiency, and other drivability problems. Recirculating diverter valves prevent these issues while still improving performance.
Question #6 - Does a diverter valve make any sound?
On a stock intake and car, diverter valves are typically silent. However, with an aftermarket intake, you’ll hear a distinct, cool sound when the valve operates. The sound is subtle compared to a blowoff valve but still satisfying.
Question #7 - Why should I upgrade my diverter valve?
Upgrading to our aftermarket diverter valve offers several benefits:
- Eliminates Boost Leaks: Factory diverter valves often have seals that degrade over time, causing boost pressure to escape.
- Improves Drivability: Smoother transitions enhance throttle response and overall driving experience.
- Durable Construction: Our valves are machined from billet aluminum, feature a red anodized finish for corrosion resistance, and are designed with simplicity in mind. With only three parts—a piston, spring, and cap—there’s minimal risk of wear or failure.
Fitment-
- 2019-2024 Subaru Ascent
- 2020-2024 Subaru Legacy XT
- 2022-2025 Subaru Outback Wilderness
- 2020-2024 Outback XT
- 2022-2024 Subaru WRX
You’ve watched the video, read the FAQ, and still have questions? No worries—our tech team has your back! Shoot them an email anytime at [email protected]!