• Comment Install Une Blow Off Valve

Tuning guide 'Blow off valves or dump valves' Blow off valves or dump valves Guide. In a turbo engine the pressures build up as air is compressed and forced into the engine. The turbo is driven by the exhaust gases so the faster the engine goes the more air you get forced into the engine. This is fine until you lift off the accelerator. Stupid people blow stuff up. The mbc is just a tool they use in the destruction process. Easiest install is take the vacuum lines going into the n75 and use them for the mbc. And if you are using a stock turbo get a bleed valve mbc which would be much smoother than a ball and spring mbc.

This guide is to assist with the installation of the Agency Power Adjustable Blow-Off Valve kit on the Polaris RZR XP Turbo 16-18

Step 1. Remove the stock diverter valve by cutting and removing the two pinch clamps retaining the diverter valve to the charge pipe and intake return hose. Remove the vacuum hose attached to the diverter valve and remove from the RZR

*NOTE* The pinch style clamps are made from stainless steel and can take some force to cut fee.

Step 2. Next remove the intake return hose from the intake pipe by removing the clamp. Remove the intake return hose from the RZR

Step 3. Use the supplied rubber cap and worm drive clamp to plug the port on the intake pipe.

Comment Install Une Blow Off Valve

Step 4. Using the supplied clamps go ahead and install the adjustable blow-off valve to the charge pipe. Ensure the blow-off valve is fully seated into the charge pipe before tightening the clamp.

Step 5. Extend the vacuum hose from the “T” connection to the blow-off valve by replacing it with the supplied extended vacuum hose. If needed trim the new supplied hose to desired length. re-use the oem mesh wire shielding.

Adjusting the Blow-Off Valve

The Agency Power Adjustable Blow-Off Valve does not come preset and will need to be adjusted to suit the vehicle.

To adjust the valve turn the cap either clockwise or counterclockwise. Turning the cap on the valve counterclockwise will decrease the pressure on the piston, while turning the cap clockwise will increase the pressure on the piston.

• Start with the cap on the valve set to its maximum softest setting. Do not rotate past the O-Ring. The O-Ring should be completely covered by the cap.
• Start the vehicle and let it idle.The port should be closed off by the piston and not floating or moving.
• Rev the engine in park and let off quickly, the engine should return to normal idle speed and the valve should be closed. If the valve is open tighten the cap clockwise one turn and test again.
• Test drive the vehicle. The BOV should remain closed under throttle/boost and open momentarily when releasing the throttle.

Turbocharging continues to gain popularity.

But there are still a few areas of a typical turbochargersetup that remain fuzzy to turbo newbies. One of the most common misunderstandings involves the basic difference between a wastegate and a blow-off valve.

So here goes…

What is a Wastegate?

A wastegate prevents the turbo from creating too much boost.

Once the exhaust pressure from the engine spins the turbo’s turbine wheel fast enough to produce the desired level of boost, the wastegate will open to redirect the excess exhaust pressure around the turbine wheel. This keeps power levels at the desired level and prevents too much boost, which could cause detonation and engine damage.

Most wastegates operate off of pressure, or pneumatically, using an actuator spring. As pressure reaches a determined level of PSI, the spring is pressed open, actuating a valve which allows the exhaust gases to flow past the turbine and through the wastegate. These exhaust gases are essentially “wasted” because they no do not help spin the turbine wheel. The wasted exhaust gases will travel through the wastegate so long as peak boost is held.

Computer-controlled wastegates operate a bit differently. They use a sensor, which signals the ECM when boost pressure goes too high. When the pressure becomes too high, the ECM signals a solenoid valve that opens the wastegate.

There are a couple different configurations for wastegates. External wastegatesare located on the exhaust side of the turbo unit, between the exhaust turbine wheel and the exhaust manifold. At this location, the wastegate can get the exhaust flow upstream of the turbine and then route it back into the exhaust on the other side. Internal wastegates are located within the turbocharger housing itself and offer a more compact option with less piping.

What is a Blow-Off Valve?

A blow-off valve (BOV) is similar to a wastegate, but works on the intake side of the turbocharger.

The BOV prevents pressure from building up in the intake tract. Excess pressure in the intake (ahead of the turbo) can back up and then cause compressor surge when the engine speed changes suddenly. The BOV is normally closed, but when a certain pressure level is achieved, the inlet air opens a spring to relieve the backed-up pressure. This reduces stress on the compressor and its bearings.

If you’ve ever heard a turbo car make a hissing sound, that’s the blow-off valve allowing excess pressure to escape when the driver suddenly lets off the throttle.