Best Blow Off Valves: Get More Sound From Your Engine
Use any of these blow-off valves to produce great turbo sounds
The Review Team
How We Decided
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PUBLISHED ON October 13, 2019
Many turbocharged cars lack a powerful sound when shifting. That can be changed with a blow-off valve (BOV) that takes the load off the turbo when you are decelerating to create a smooth hissing sound. Our buying guide will help you find the best blow-off valve to keep your turbocharged engine operating at its optimal level.
- Best OverallTurbosmart Blow Off ValveSummarySummaryA compact and lightweight blow off valve designed to amplify sounds and prevent any compressor surge.ProsProsSolidly built. Sleek design. Great amplified sound. Optimal quality and functionality. Easy to install. Space-efficient. Fits modern eco-engines. Stays quiet at normal speeds.ConsConsNot a universal fit. May start to leak under heavy boost. It may be too loud and annoying with time.
- Best ValueDewhel Universal Blow Off ValveSummarySummaryA universal fit and fast-responding blow-off valve that performs beyond its price tag.ProsProsAffordable. Durable body. Available in a variety of colors. Improved valve control. Effectively responds to high boost pressures. Supports new turbochargers. All mounting hardware included.ConsConsMay need an adaptor to fit in your engine. Professional installation may be required. Stiff spring.
- Honorable MentionGReddy Blow Off ValveSummarySummaryA quick-responding blow-off valve that guarantees high performance regardless of the external conditions.ProsProsResponds well to high and low boost. Fits most engines. Durable construction. Produces a loud sound. Dependable. It doesn’t need a mounting adaptor. Great airflow and response. Customizable dual spring system.ConsConsExpensive. It doesn’t come with a flange. Some parts may be missing from the package.
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- Observe a six-month cleaning interval for your BOV to remove dirt and other power-robbing contaminants. A dirty BOV sounds bad and can damage the turbocharger with time.
- Since you have to remove the BOV when cleaning it, you may want to take a picture before removing the unit to ensure that you return everything to the right place. Also, be careful not to crack or damage the brittle fittings when loosening the bolts.
- Remember to inspect the BOV unit for any signs of corrosion, scarring, and wear. Lubricate the metal parts with a non-viscous lubricant, and you can use pressurized air to clean out the BOV before reassembling it.
Q: Can a blow-off valve damage the turbo?
A: Not if it’s installed correctly on the turbocharger. In contrast, it will maintain the best blow-off valve in your engine to prolong its life. It will also minimize surge loading and help maintain turbine speeds in between shifts. It should be fitted between the throttle plate and the turbocharger compressor.
Q: Can I install a blow-off valve in a supercharged car?
A: Blow off valves can cause performance issues in supercharged cars. They are only designed for turbochargers. A supercharger is fitted with a forced induction instead, which is designed to recognize pressure build-up and vent it off. That’s similar to what a blow-off valve does for a turbocharger.
Q: What’s the difference between a blow-off valve and a wastegate?
A: Both units work to regulate the pressure of exhaust gases but in different ways. The turbocharger helps discharge pressure from the turbo when the throttle is suddenly released. A wastegate regulates the level of a boost from the turbo by redistributing the excess pressure from the boost to the turbine wheels with the help of an actuator spring.
We chose the Turbosmart Blow Off Valve as our top pick for the best BOV unit since it’s solidly built to outperform its competitors. It also adds a nice sound enhancement to your turbocharger and is quite easy to install.
If you are looking for a more affordable BOV unit, consider the Dewhel Universal Blow Off Valve. It will significantly enhance the shifting in your turbo-boosted engine and produce superior sounds.