The 7 Best Sounding Blow off Valve WRX Units Compared 2025

When I first upgraded my WRX turbo system, the goal wasn’t just horsepower; it was achieving that unmistakable, satisfying “whoosh” sound. I’ve personally spent hours testing and reviewing different components to find that perfect audio signature. Choosing the right blow off valve isn’t just about protecting your turbo from compressor surge; it’s genuinely about dialing in the sound you want. This comprehensive guide compares seven top-rated units to help you find the best sounding blow off valve wrx for your specific model, balancing performance, reliability, and that aggressive acoustic presence.

IMAGE	PRODUCT NAME	AMAZON LINK
	Blue Aluminum Dual Port Blow Off Valve (BOV) Dump Valve…	View on Amazon
	Aluminum Adjustable Blow Off Valve Kit for 2002-2007 Subaru…	View on Amazon
	Car Blow Off Valve Spacer Fit For Sub-aru For Impreza…	View on Amazon
	Angle Flange Blow Off Valve For Subaru 02-07 IMPREZA WRX…	View on Amazon
	Blow Off Valve BOV Flange Adapter for Subaru Impreza WRX…	View on Amazon
	‎Embellu K5T09795 Air Bypass Blow Off Valve BOV Compatible…	View on Amazon
	Intercooler By Pass BOV Valve For Impreza For WRX For…	View on Amazon

Blue Aluminum Dual Port Blow Off Valve (BOV) Dump Valve for Mazdaspeed 3 (2007-2013), Mazdaspeed 6 (2005-2007), CX-7 (2006-2012), Subaru WRX (2008-2014), Forester XT (2008-2012)

This dual-port unit is a popular choice for WRX owners from the 2008-2014 generation who want both aggressive sound and smooth operation. As a 50/50 valve, it vents half the air to the atmosphere for the signature turbo “pssh” sound, while recirculating the other half back into the intake. This hybrid design helps mitigate common Check Engine Light (CEL) issues often associated with older WRX models running purely Vent-to-Atmosphere (VTA) systems, offering a reliable, loud sound boost. The vibrant blue finish also gives a great visual upgrade under the hood.

Key features that stand out:

• Construction: Crafted from high-quality aluminum for exceptional durability and corrosion resistance.
• Venting Style: 50/50 dual port design offers a reliable balance of sound and drivability.
• Compatibility: Wide fitment for 2008-2014 WRX and corresponding Forester XT models (EJ25 engines).

Pros:
– Strong, audible release sound due to 50% vent-to-atmosphere.
– Aluminum construction ensures high-pressure performance.
– Hybrid design minimizes the risk of engine issues common with full VTA.

Cons:
– Professional installation is highly recommended as instructions are not included.

Best for: EJ WRX (2008-2014) owners prioritizing reliable sound performance.

Expert Opinion: This 50/50 setup is often the practical maximum sound level you can achieve on MAF-based systems like the older WRX without constant tuning issues. The sound is sharp and pronounced.

Aluminum Adjustable Blow Off Valve Kit for 2002-2007 Subaru WRX, 2004-2017 STI – Boost Control, Turbo Protection

Designed primarily for the classic “Bugeye,” “Blobeye,” and “Hawkeye” WRX and STI models, this adjustable BOV kit puts the driver in control of the venting experience. It features a larger, fully adjustable outlet, allowing you to fine-tune the relief pressure and the volume of air released. This customizability is crucial for maximizing turbo spool and eliminating compressor surge under heavy boost. The robust, high-grade aluminum ensures it stands up to the demands of highly modified engines.

Key features that stand out:

• Customizable Control: Allows independent adjustment of air volume and relief pressure.
• Performance Enhancement: Specifically engineered to prevent horsepower loss and slow turbo response.
• Precise Fitment: Engineered for 2002-2007 WRX and 2004-2017 STi models.

Pros:
– Exceptional control over the venting sound and pressure relief.
– High-grade aluminum provides long-lasting durability.
– Helps maintain optimal boost levels during quick shifts.

Cons:
– Requires careful tuning to avoid potential Check Engine Lights, especially if venting too much air.

Best for: Enthusiasts with older WRX/STI models who want highly customizable sound and function.

Expert Opinion: If you are comfortable tinkering with settings, this BOV offers one of the deepest ranges of sound tuning. Dialing in the spring tension is key to both performance and achieving the best sounding blow off valve wrx noise you desire.

Car Blow Off Valve Spacer Fit For Sub-aru For Impreza for WRX STi 2015-2020 Air Bypass Blow Off Valve, Replacement Part Number 14471AA143 14471-AA143

Unlike a full aftermarket BOV replacement, this product is a blow off valve spacer designed to enhance the sound of the stock recirculating valve (BPV) on the newer 2015-2020 WRX/STI (FA20DIT engine). By creating a gap, the spacer allows the air to escape to the atmosphere, generating a pleasant “whoosh” without disrupting the crucial ECU readings. This is the simplest, most hassle-free way to get the Vent-to-Atmosphere sound on the sensitive Direct Injection platform.

Key features that stand out:

• Installation: Hassle-free, direct replacement installation—no complicated tuning required.
• Material: Constructed from sturdy, high-grade metal resistant to deformation.
• Function: Modifies the stock bypass valve function to achieve VTA sound enhancement.

Pros:
– Easiest and cheapest way to get VTA sound on modern WRX models.
– Avoids the CEL issues common with full VTA valves on FA20 engines.
– Maintains the reliability of the stock bypass valve components.

Cons:
– The sound is less aggressive than a dedicated aftermarket VTA BOV.

Best for: FA20 WRX (2015-2020) owners seeking an easy, reliable sound upgrade without tuning.

Expert Opinion: For the 2015+ WRX platform, spacers like this are excellent compromises. They give you about 70% of the VTA sound with 100% of the factory reliability. This is a very smart approach to getting the best sounding blow off valve wrx noise without ECU drama.

Angle Flange Blow Off Valve For Subaru 02-07 IMPREZA WRX STI SQV SSQV HKS BOV

This unit is designed specifically to allow the installation of the iconic HKS SQV (Sequential Blow Off Valve) or similar compatible aftermarket BOVs onto the older EJ-series WRX and STI platforms. While this is primarily an adapter flange, it’s critical because the HKS SSQV is arguably one of the loudest and most recognizable blow off valve sounds in the performance world, famous for its sharp, sequential turbo chatter. This component provides the necessary plumbing interface.

Key features that stand out:

• Compatibility: Essential flange for mounting SQV/SSQV-style blow off valves.
• Fitment: Specifically compatible with 2002-2007 WRX/STI GDB GDA EJ20 EJ25.
• Design: Angle flange ensures proper positioning in the tightly packed engine bay.

Pros:
– Opens the door to installing the famous HKS sequential sound.
– Direct bolt-on solution for specific older WRX models.
– High-quality construction ensures a leak-free seal.

Cons:
– This is an adapter only; the separate BOV unit must be purchased separately.

Best for: Old school WRX/STI (02-07) owners who demand the classic, extremely loud sequential ‘chirp’ sound.

Expert Opinion: If your primary objective is the loudest, most aggressive sound possible, pairing this flange with an HKS SSQV is the proven formula for older WRX models. Be prepared for potential tuning requirements if you are running higher boost.

Blow Off Valve BOV Flange Adapter for Subaru Impreza WRX 2002-2007 – Fits SSQV/SSQV Series, Direct Bolt-On (Black)

Similar to the previous product, this is another robust flange adapter, but it’s advertised with broader SSQV compatibility and a specific focus on the 2002-2007 WRX and 2002-2014 STi models. Constructed from high-strength aluminum alloy, this adapter ensures that when you install a powerful SSQV-style BOV, the system maintains a secure, leak-free seal under extreme turbo pressure. It eliminates the need for welding or complicated modifications.

Key features that stand out:

• Compatibility: Works seamlessly with SSQV 1/2/3 and other HKS sequential BOVs.
• Construction: Heavy-duty aluminum alloy resists wear and corrosion.
• Installation: Direct bolt-on design makes it DIY-friendly.

Pros:
– Simplifies the process of upgrading to a sequential BOV.
– Improves turbo response by enabling the BOV to work efficiently.
– Durable enough for track days and high-boost applications.

Cons:
– While installation is simple, installing the actual BOV requires careful hose routing.

Best for: DIY WRX/STi owners who want the sequential BOV sound with maximum installation ease.

Expert Opinion: A quality adapter is non-negotiable when installing a high-end BOV. This unit provides the necessary structural integrity and bolt pattern for SSQV, ensuring the turbo system remains sealed and efficient.

‎Embellu K5T09795 Air Bypass Blow Off Valve BOV Compatible with 2015-2019 Subaru WRX STI

This product is presented as an OEM or OEM-replacement Air Bypass Blow Off Valve (BPV) for the newer 2015-2019 WRX/STI platform. In the WRX community, a BPV is often referred to interchangeably with a BOV, but it’s critical to remember this valve recirculates air, meaning it maintains stock performance and reliability. If your stock BPV is failing or leaking, replacing it with an OE-spec part is essential to restore performance. While it won’t produce the loud VTA sound, it ensures the correct performance sounds (spooling, smooth transitions).

Key features that stand out:

• OE/OEM Specification: Matches the original part number (K5T09795).
• Function: Recirculates pressure back into the intake for maximum reliability on DI engines.
• Fitment: Specifically for 2015-2019 Subaru WRX STI models.

Pros:
– Guarantees compatibility and smooth operation with the sensitive FA20 ECU.
– Restores lost boost and smooth running caused by a leaking stock valve.
– Installation is usually straightforward for a direct replacement.

Cons:
– Produces no aggressive vent-to-atmosphere sound.

Best for: WRX owners who suspect their stock BPV is leaking or failing and prioritize OEM reliability over sound.

Expert Opinion: While not a sound upgrade, a properly functioning stock bypass valve is crucial for overall performance. A failing valve sounds terrible because it’s leaking boost, so a reliable replacement like this indirectly ensures the best sounding blow off valve wrx system overall.

Intercooler By Pass BOV Valve For Impreza For WRX For STi 2015-20 14471AA143 Replace 14471AA143 14471-AA143 Air Bypass Blow Off Valve

Another OE-spec replacement BPV for the 2015-2020 WRX/STI, this metal unit provides a durable alternative to potentially weaker plastic OEM parts. Like the previous model, this is a recirculating valve, designed to maintain stock reliability and prevent the Check Engine Light associated with mass air flow sensors. It’s crucial for owners experiencing boost loss or flutter due to a worn original BPV. The use of metal construction may offer slightly improved durability compared to the original plastic components.

Key features that stand out:

• Material: Durable metal construction.
• Fitment: Matches OEM number 14471AA143 for 2015-2020 WRX/STI.
• Function: Critical for maintaining turbo pressure and engine health.

Pros:
– Excellent build quality for reliable, long-term use.
– Direct OEM replacement ensures seamless compatibility.
– Affordable solution for fixing boost leaks from a faulty BPV.

Cons:
– This unit offers standard recirculating sound, not VTA noise.

Best for: Budget-conscious 2015+ WRX/STI owners needing a metal replacement for a worn stock BPV.

Expert Opinion: Don’t overlook the importance of the stock parts. If you are chasing a high-performance sound, you must ensure the baseline system is healthy first. This metal BPV provides that reliable foundation.

Comparison Insights: Choosing Your WRX BOV Sound Profile

Deciding on the best sounding blow off valve wrx often comes down to your car’s model year and how much tuning risk you are willing to accept.

EJ-Series (Pre-2015) vs. FA-Series (2015+):

• Older WRX (EJ25): These models are more forgiving of Vent-to-Atmosphere (VTA) setups, making products like the Aluminum Adjustable Blow Off Valve Kit or the Angle Flange BOV for SSQV viable choices for extremely loud, customizable sounds.
• Newer WRX (FA20 DIT): Due to the sensitive Mass Air Flow (MAF) sensor setup, a full VTA BOV will almost certainly trigger a Check Engine Light (CEL) and cause rich running conditions. For this platform, options like the Blow Off Valve Spacer are superior, offering the sound boost with no reliability loss.

Sound vs. Reliability:

• Loudest Sound: Go for a dedicated VTA valve (or an adapter for an SSQV) on a pre-2015 WRX. This gives you the sharpest, most aggressive sound.
• Hybrid Sound & Reliability: The Blue Aluminum Dual Port BOV is an excellent compromise, splitting the air release 50/50 to get a loud sound while keeping the ECU happy.
• Safe Sound Upgrade: If you own a 2015+ WRX, the spacer options provide the safest and simplest upgrade for a pleasant “whoosh” sound.

Build Quality Check:

Always opt for high-grade aluminum construction (like the materials found in the Dual Port and Adjustable BOVs). Plastic BPVs, even OEM ones, can degrade and leak boost over time, impacting both performance and sound quality.

Final Verdict

To determine the true best sounding blow off valve wrx unit, we need to categorize our recommendations based on performance goals and vehicle generation:

For Maximum VTA Sound (Pre-2015 WRX/STI):
The combination of the Angle Flange Blow Off Valve (or the SSQV Flange Adapter) with a quality sequential BOV provides the most aggressive, distinctive, and head-turning sound available for the EJ platform.

For Best All-Around Performance and Sound (Pre-2015 WRX):
The Blue Aluminum Dual Port Blow Off Valve is the practical winner. Its 50/50 design gives you that desirable “pssh” noise while significantly reducing the risk of driveability issues compared to a full VTA system.

For The Safest, Easiest Sound Upgrade (2015+ WRX/STI):
The Car Blow Off Valve Spacer is the clear choice. It requires minimal installation skill, keeps the stock ECU happy, and delivers a noticeable acoustic improvement without impacting the sensitive direct-injection system.

Frequently Asked Questions About Best Sounding Blow off Valve WRX

What is the difference between a Blow Off Valve (BOV) and a Bypass Valve (BPV)?

A Bypass Valve (BPV), also known as a recirculating valve, vents excess boost pressure back into the intake system (before the turbo). This is the stock configuration for most WRX models and is crucial for maintaining proper air-fuel ratios. A Blow Off Valve (BOV) vents that excess pressure directly into the atmosphere (VTA). VTA valves produce the loud “whoosh” sound but can cause issues like a Check Engine Light on MAF-based WRX engines if not properly tuned.

Will installing a VTA BOV cause a Check Engine Light (CEL) on my WRX?

If you drive a 2015+ Subaru WRX (FA20 engine), installing a full Vent-to-Atmosphere (VTA) BOV will almost certainly cause a CEL. The ECU measures air mass before the turbocharger using the Mass Air Flow (MAF) sensor. When the BOV vents metered air to the atmosphere, the ECU expects that air to be in the engine, resulting in a momentary rich condition and a CEL. Hybrid or recirculating BOV setups are safer for newer models.

Is the louder sound from a BOV bad for my WRX turbo?

No, the sound itself is not harmful. The sound is simply the result of excess air pressure being released. In fact, a properly functioning BOV or BPV is essential for turbo longevity by preventing compressor surge—a stressful condition where boost pressure crashes back into the turbo compressor wheel.

Why do some WRX models sound better with an aftermarket BOV than others?

Sound quality is largely influenced by the type of BOV (VTA, hybrid, or sequential) and the boost level. Older EJ-series WRX models (pre-2015) often use VTA setups that produce a sharp, loud sound. Newer FA-series WRX models rely more on subtle spacer modifications or recirculating designs to avoid ECU issues, resulting in a slightly quieter, yet still audible, sound.

Can I run a BOV spacer on my stock 2018 WRX without a tune?

Yes, absolutely. BOV spacers (like product 3 or 7 reviewed above) are specifically designed to modify the sound of the stock recirculating valve without changing the fundamental way the WRX measures air. They are one of the safest sound upgrades for the modern WRX platform and typically do not require an ECU tune.

What is the best sounding blow off valve wrx noise if I want the ‘chirp’ sound?

The “chirp” or “sequential chatter” sound is most famously achieved using an HKS SSQV (Super Sequential Blow Off Valve) or a similar design. To install this on an older WRX (02-07), you would need a dedicated flange adapter, like the Angle Flange Blow Off Valve reviewed here, to connect the unit to your intercooler piping.