by Joshua Thomas
When tuning a vehicle for performance, you will often come across terms like the blow off valve or the turbo. The turbo will feed the engine with compressed air in an optimal and efficient manner. This allows the engine to deliver higher performance that it normally would without a turbo.
However, having a turbo alone is not enough to get more horsepower from your vehicle. You also need to install a blow off valve.
The blow off valve or divergent valve serves only one purpose. It evacuates any excess air pressure buildup before it reaches the engine. This allows the engine to burn fuel optimally without choking with an excess of air.
In the process of evacuating excess air, the blow off valve produces a distinctive whoosh sound that is commonly associated with a sports vehicle that has been tuned.
Below, we have reviewed some of the best blow off valves for the money. Let's see which valve model you need to purchase for your car right now!
1. Boomba Racing 022-00-006R (Best Overall)
2. Greddy 11501665
3. Turbosmart TS-0203-1022
4. TiAL Sport Q.11R Q Series
5. XS Power ssauto6050 Mazdaspeed
6. TurboXS BOV-SML
What separates the Boomba from the rest of the competition is its internal brass piston design that helps boost its performance and durability.
It also has a small and compact form factor so it doesn't take a lot of space when installed. Therefore, this blow off valve is an excellent choice for those who do not have a lot of space under the hood of their vehicle.
Since brass is a non-reactive metal, it will last a long time, even if this blow off valve comes in contact with oil or water. It will not rust or corrode. Furthermore, the brass piston ensures that this valve is performing and reliable in the long term.
Most impressively, this valve has been tested to withstand a high air pressure of up to 70 PSI. This is extraordinary considering that most blows off valves have a tolerance value that is significantly less than 70 PSI.
The high air pressure tolerance is most probably explained by the presence of the brass piston.
The only issue we take with this blow off valve is that since most of its functionality is found inside of the valve, it lacks versatility in adjustments.
The Greddy is a popular blow valve that you will find in the vehicles of many car enthusiasts. Not only is this blow valve high-performing, but it is also compatible with almost any type of vehicle on the market. This is mostly due to its universal inlet and outlet design and standard diameter.
Inside this blow off valve, you will find a silicone diaphragm controller that is heavy-duty and long-lasting. Also, it sports an improved design over the previous model which offers better response times especially when you change gear in your vehicle.
This model also contains a CNC outlet that uses a special technology that amplifies the blow off sound without the need for additional air pressure. But best, it uses the same mounting holes as previous Greddy blow off valves so if you are looking for an upgrade, then this model is definitely the best blow off valve for the money.
However, this model has a few disadvantages. A few customers have complained about poor shipping packaging. Also, it's exterior build construction is not as tough and robust when compared to other models.
Most people are looking forward to installing a blow off valve on the vehicle usually face a big problem. That is incompatibility.
In fact, blow off valves usually, tend to be picky about the type of vehicle that they are installed on. This is not a problem with this Turbosmart blow off valve because it is universally compatible with almost any vehicle on the market.
You will have absolutely no problem installing it and getting it to work right away because it has dual 25 mm ports. Moreover, it has been internally designed in such a way that it provides your engine with a superior airflow as well as a better sound when you shift your gears.
The exterior build construction is superb as it is made from a metal that has been powder coated. Of course, you can quickly and easily adjust the sound of this blow off valve by simply turning the lever left or right at the top of the device.
Just make sure that you know how to install a blow off valve in your vehicle because this model does not come with an instruction's manual. You may need some experience to install it.
Notes: This blow off valve is very loud and may be compatible only for off-road racing vehicles and cannot be used on roads. You may need to inquire to ensure that this model is compliant with your state laws.
The TiAL has been designed with a 50mm port that will allow a lot of air to flow to the motor. It also sports a heavy-duty diaphragm inside that allows it to make a loud whoosh sound when blowing off the sound.
In addition, this valve comes with all installation accessories like 1/4 inch hose attachments. Installation is very beginner-friendly and quite straight forward.
Furthermore, the mounting clamp at the bottom of this blow off valve gives this model its distinctive look. It is worn and tear resistant, and since it is made from a corrosion-free metal, it will be long-lasting as well.
When compared to previous TiAL models, this unit allows roughly 60% more air which definitely makes it a significant improvement.
This valve is also quite heavy-duty as this blow off valve will comfortably work on a powerful vehicle with a big engine, of up to 1,800 hp. Pretty impressive!
A small disadvantage that we can point out is that for the price, we expected it to come with a recirculating kit but it does not. However, it is not very difficult to get one.
One big problem with the blow off valve is that they tend to be quite expensive and outside the budget of most people. This is not a problem with the XS Power because it is the best blow off valve when it comes to price in this review.
Having a small price does not necessarily mean bad quality. Indeed, this model is made from a high-grade aluminum metal that will not corrode and is quite resistant to wear and tear.
Also, installation is quite easy, and it comes with 2 mounting holes at the base for you to firmly bolt it to your vehicle. Adjustments to the sound can easily be made with the hex screw at the top.
And even if this model has been made to work with Mazda cars, you can tweak it a little bit and make it work on other vehicles as well.
Moreover, this unit doesn't come with any hex screws to adjust the sound. You will need to own those tools firsthand. Also, even if it has a decent build construction, it is not as durable when compared to the competition. Nothing big, but still noteworthy points to keep in mind.
If you do not have a lot of height under the hood to install your blow off valve, then the TurboXS is the right model for your need. Indeed, this is a very low-profile blow off valve that despite its small height is still heavy-duty and produces a loud sound.
But where this blow off valve really shines is in its design. It has a universal fit and can be installed on almost any vehicle with ease. You are not restricted to specific car models like a most other blow off valves in this review.
Furthermore, this unit lacks the adjustment that you can make in other blow off valves but it is very easy to install, as it comes with mounting holes at the base for a secure fit. Also, it is a little bit more expensive but the high-quality build construction and universal design easily makes up for this small caveat.
There are several types of blow off valves on the market. Here are 2 of the most common types that you will encounter.
Vented : The vented blow off valve is the most popular type of aftermarket blow off valve that you can purchase.
It produces the distinctive whoosh sound because this blow of valve evacuates excess air pressure that comes directly from the turbo system outside of the vehicle.
Recirculated : On the other hand, the recirculated blow off valve is usually a silent blow off valve that is factory fitted.
This type of blow off valve "recirculates" compressed air back to the intake (before the turbo) so as to provide more responsiveness to the turbo system when you shift gear.
By design, blow off valves are generally not universally compatible with all vehicles. Rather, manufacturers make them in order to fit a specific type of vehicle.
Therefore, each blow off valve model has an air inlet and outlet of varying sizes. For reference, 40 mm is the most popular diameter of your blow off valve.
Nevertheless, you will still need to ensure that your vehicle is compatible with a particular type of blow off valve.
If you are unsure, you may need to check the manufacturer's website or the product description to know about the compatibility.
The blow off valve is reputed for its whoosh sound. The sound level in a blow off valve is measured in decibels. And most reputable and top-rated blow off valves on the market tend to be very loud.
Therefore, so as to comply with laws, you need to ensure that the blow off valve does not produce a sound that is above tolerable levels.
Furthermore, each blow off valve will produce a distinct sound, and this sound will depend on their internal design, shape, and size.
Being able to adjust the sound of your blow off valve as well as the amount of air that it delivers to your engine is vital.
Most blows off valve have a special mechanism that allows you to tune those settings with a screwdriver.
However, each model has its own specificities, and you may need to check your user manual to learn how to make adjustments to your blow off valve.
You don't need any special tools or spend hours to install the blow off valve. In fact, most models are very straightforward and easy to install by absolute beginners.
If you have never installed a blow off valve before, then make sure that the manufacturer ships their product with a detailed instructions manual. It will show you exactly how to install the blow off valve on your vehicle.
As any other accessory installed in your vehicle, the blow off valve will suffer from wear and tear.
Therefore, you need to perform regular maintenance every few months to ensure that the blow off valve is working in tiptop conditions.
One factor that directly affects the performance of the blow off valve is leakages. Make sure to inspect your blow off valve for any leakages of oil and air.
Go Fast Bits DV+ T9356 Diverter / Blow Off Valve for Dodge Dart / BMW F30 335i F20 F21 - Walmart Link
Turbosmart TS-0203-1022 Kompact 25 mm Dual Port Universal Fit Blow Off Valve , Black - Walmart Link
Go Fast Bits T9351 dv+ Blow off Valve or BOV/diverter valve with TMS advantage - Walmart Link
Turbosmart TS-0203-1209 Kompact Plumb Back Blow Off Valve for Mazda/Subaru,Black - Walmart Link
Forge Motorsport FMDVMK7A Blow Off Valve Kit - Black - Walmart Link
YOOWEE BPV/Blow Off Valve for Subaru WRX 2015+/Forester XT 2014+ Red & Shifter Stop - Walmart Link
Go Fast Bits DV+ T9356 Diverter / Blow Off Valve for Dodge Dart / BMW F30 335i F20 F21 - eBay Link
Turbosmart TS-0203-1022 Kompact 25 mm Dual Port Universal Fit Blow Off Valve , Black - eBay Link
Go Fast Bits T9351 dv+ Blow off Valve or BOV/diverter valve with TMS advantage - eBay Link
Turbosmart TS-0203-1209 Kompact Plumb Back Blow Off Valve for Mazda/Subaru,Black - eBay Link
Forge Motorsport FMDVMK7A Blow Off Valve Kit - Black - eBay Link
YOOWEE BPV/Blow Off Valve for Subaru WRX 2015+/Forester XT 2014+ Red & Shifter Stop - eBay Link
If you have a turbo installed on your vehicle, then you absolutely must have a blow off valve.
It will allow your vehicle to evacuate any excess pressure buildup and make your engine run optimally and efficiently.
You simply install it between the inter-cooler and the throttle body and all you will need is a few minutes of your time.
Finally, our blow off valve review above contains some quality models that are well worth it. If you are not sure which blow off valve to purchase yet, then read the review one more time.
About Joshua Thomas
Joshua Thomas just simply loves cars and willing to work on them whenever there's chance... sometimes for free.
He started CarCareTotal back in 2017 from the advices of total strangers who witnessed his amazing skills in car repairs here and there.
His goal with this creation is to help car owners better learn how to maintain and repair their cars; as such, the site would cover alot of areas: troubleshooting, product recommendations, tips & tricks.
Joshua received Bachelor of Science in Mechanical Engineering at San Diego State University.