In the world of turbocharged engines, the blow off valve (BOV) plays an essential role in maintaining peak performance and longevity. Originally developed for race cars, turbochargers have become increasingly common in street vehicles, and with them, blow off valves have become a key component. For drivers looking to maximize their turbocharged car's performance, understanding the function of blow off valves—and considering an upgrade—can make a significant difference both on the road and the track.
What is a Blow Off Valve?
A blow off valve is a pressure-relief device located between the turbocharger and the throttle of a car’s engine. When a turbocharged engine operates at high speeds, the turbocharger forces a large amount of air into the engine. However, when the driver suddenly releases the accelerator, the throttle valve closes, and the forced air has nowhere to go. If this pressurized air is trapped, it can flow back into the turbocharger, causing a phenomenon known as compressor surge, which can damage the turbo components over time.
The blow off valve prevents compressor surge by releasing excess pressure back into the atmosphere or into the intake system. This pressure relief not only protects the turbocharger from excessive wear but also contributes to the efficiency of the turbo system by allowing it to spin freely when not needed, preparing it for the next burst of acceleration.
Why OEM Blow Off Valves Are Often Substandard
Original Equipment Manufacturer (OEM) blow off valves are usually designed to meet basic performance and durability standards. Since they are created with the average driver in mind, manufacturers often prioritize cost and noise reduction over high-performance functionality. This means that OEM blow off valves are generally constructed with lower-grade materials, such as plastic or rubber, which degrade faster under the heat and pressure associated with turbocharged engines. These materials are prone to leaking or cracking over time, leading to compromised performance.
In addition to their materials, OEM blow off valves tend to have weaker springs that are less effective at holding high levels of boost pressure. For a driver who pushes their car for peak performance, either in street racing or on the track, an OEM blow off valve may fail to release pressure efficiently, reducing the engine's power and throttle responsiveness. This inefficiency can create lag in acceleration, making it harder to achieve and maintain optimal boost levels during spirited driving.
WeSellPerformance.com Related Brands for Blow Off Valves
Benefits of Upgrading a Blow Off Valve for Street and Track Performance
For the performance enthusiast, upgrading to an aftermarket blow off valve can deliver multiple advantages, enhancing both reliability and driving experience.
1. Improved Durability
Aftermarket blow off valves are typically made from high-grade materials like aluminum or stainless steel, making them more resistant to the intense heat and pressure of a turbocharged engine. This increased durability ensures that the BOV can withstand high boost levels without cracking, warping, or leaking. Drivers who enjoy pushing their cars to the limit benefit from a more resilient component that won't fail under high pressure, meaning a more reliable driving experience on the street and track.
2. Better Boost Management
Upgraded blow off valves are designed with more robust springs and diaphragms, which allow them to hold higher levels of boost pressure without prematurely releasing it. This means that when accelerating, the turbocharger can maintain consistent pressure, delivering more power to the wheels. On the track, where maintaining peak boost can make the difference in lap times, a reliable aftermarket blow off valve provides an edge by enabling quicker throttle response and minimizing turbo lag.
3. Enhanced Throttle Response
With an upgraded blow off valve, the car experiences less turbo lag, the delay between throttle input and boost response. This improvement is particularly noticeable during rapid acceleration or gear changes, where maintaining power is crucial. An aftermarket BOV can vent pressure almost instantly, allowing the turbocharger to maintain its momentum. This can improve throttle response significantly, which is beneficial for street performance and essential for competitive track driving.
4. Distinctive Sound and Aesthetic Appeal
For many car enthusiasts, the sound of a blow off valve is part of the allure of a turbocharged engine. Aftermarket BOVs often come with adjustable settings that allow the driver to customize the sound and intensity of the “whoosh” as pressure is released. This feature is popular among street drivers who want a unique, more aggressive sound, adding an extra layer of enjoyment and style to their driving experience. Additionally, many upgraded blow off valves are available in various finishes, allowing drivers to personalize their engine bays for visual appeal.
Key Factors to Consider When Upgrading Your Blow Off Valve
If you’re considering an upgrade, it’s important to choose a blow off valve that aligns with your driving style and vehicle specifications. Here are some tips:
- Material Quality: Look for valves made from durable metals, as these will last longer and handle higher pressures.
- Vent Type: Some BOVs vent to the atmosphere, creating a distinctive sound, while others recirculate the air back into the intake system. Atmospheric BOVs are louder, but recirculating BOVs can maintain engine smoothness and avoid triggering engine codes in certain vehicles.
- Adjustability: Many performance-oriented BOVs offer adjustable springs or preload settings, allowing you to tailor the release pressure to match your boost levels and driving conditions.
- Compatibility: Ensure the valve you choose is compatible with your turbo system. Certain BOVs work better with specific brands or setups, so consider consulting a professional if you’re unsure.
Conclusion
For the performance-focused driver, an aftermarket blow off valve can be an excellent upgrade, providing tangible benefits for both street and track use. OEM valves, while sufficient for general use, lack the robustness needed for high-performance driving. By upgrading to a high-quality, durable blow off valve, drivers can enjoy improved boost management, faster throttle response, and the peace of mind that comes from knowing their turbocharger is better protected against compressor surge.
Whether it’s the thrill of the distinctive blow off sound or the satisfaction of a smoother, more responsive engine, an aftermarket blow off valve enhances the turbocharged experience in ways that OEM components simply can’t match. For drivers who prioritize performance, an upgraded blow off valve is more than an accessory—it’s a valuable investment in their car’s potential.
