September 19, 2011 News

Can a BOV damage my engine?

Will a Turbosmart Blow Off or Bypass Valve (BOV/BPV) damage my engine?

The simple answer is NO. Turbosmart BOVs and BPVs are designed to improve the performance of your turbocharger system. The benefits of fitting a Turbosmart BOV are listed below:

Reduced turbo lag

Standard BOV’s are designed to be open at low vacuum levels which aid in reducing emissions. Most standard cars idle between 18 – 21 inHg. This means that when the engine is between full vacuum and 5 inHg, the valve is open, not allowing the turbocharger to pressurize the intercooler and piping. When the valve closes, the turbocharger needs to pressurize the intercooler and intercooler piping, before the intake manifold is pressurized resulting in a delay in boost pressure.

Turbosmart BOVs are designed to be closed earlier to reduce the time it takes to pressurize the intercooler and piping. Our plumb back BPVs will be just open at idle and will begin to pressurize the intercooler and piping at 15 inHg of vacuum which will result in a reduction in turbo lag. All our vent to atmosphere BOVs including the dual port are designed to be completely closed at idle resulting in intercooler and piping pressurization as soon as the throttle begins to open. This result is an instant turbo response as the valve is closed even before the throttle is open.

Due to the spring force required to keep the BOV closed at idle, the response of the BOV is reduced at low throttle openings which may result in light cavitation from the turbo charger at low RPM. This level of cavitation is negligible as the turbo speed is relatively low which means the resulting stresses on the bearings are low.

Vent to atmosphere BOVs can also cause slight over-fueling between gear changes as a portion of metered air is released from the intake system. This over fueling is not harmful to the engine as the unburnt fuel will exit the engine as exhaust. If the slight cavitation and over fueling is unwanted, then most of the benefits of fitting our vent to atmosphere BOVs are in the plumb back but without the vent to atmosphere noise, slight cavitation and slight over-fueling.

All Turbosmart BOVs (Except the Kompact Plumb Back range) are tunable to suit different applications and user preferences. Tuning the BOV to suit the users particular driving style and vehicle modifications can eliminate excessive over fueling and reduce light cavitation.

Increased sealing and pressure handling capabilities

Most factory turbocharged engines have a bypass valve which is installed to eliminate cavitation. Most of them are mass made from inferior materials such as injection molded plastic, pressed sheet metal and unreinforced rubber diaphragms. Some even have additional pressure ports on the underside so that at certain levels of pressure, they open to stop the user from increasing the maximum boost level.

All Turbosmart piston-type BOVs including the Kompact and 38mm range are made from aerospace grade billet alluminium and are machined to very tight tolerances. They are designed to withstand any boost level and will not vent under any boost conditions. The Race Port, which is a diaphragm-actuated type BOV, uses a nomex reinforced flurosilicone diaphragm which has a continuous working pressure rating of over 150 PSI. Both the Race Port and 38mm BOV range feature O-Ring seals on the piston increasing their sealing capabilities.

Most standard by pass valves have a level of acceptable pressure leak. This results in the turbocharger needing to work harder to achieve the set amount of boost pressure as it must over come the leak. From factory, most engines are working the turbochargers harder than what is actually needed.

Turbosmart BOVs are designed to provide excellent sealing of the intake system resulting in reduced stress on the turbocharger when compared to the standard bypass valves. They will not leak air pressure regardless of how much boost the turbocharger is making as there are equalizing pressures on both sides of the piston.

High Flow

All Turbosmart BOVs are designed to maximize flow at their given size. Standard valves have small and restricted flow paths that might be ok for a standard engine but are inadequate when increasing the performance of your engine. This can lead to large cavitation at high turbo speeds which will put extreme stresses on the bearings of the turbocharger.

The Kompact Range is great as a factory upgrade when you want the durability, response and sealing capabilities of a Turbosmart BOV, without needing a lot more flow capabilities compared to the standard BOV.

The 38mm range is perfect for medium modifications where much higher boost levels are used and high power outputs compare to stock are required.

The Race Port is designed to be used in extreme horsepower applications when large frame turbochargers are used and a high flowing valve BOV is needed to eliminate cavitation.