Installing a Blow Off Valve On The Ford St (2023)

FAQs

Does the Ford Focus ST have a blow off valve? ›

As any Ford Focus ST owner knows, one of the most popular mods for this vehicle is to upgrade the blow off valves and wastegates. The blow off valve is located on the boost side of the system and helps to vent boost pressure in the intake. This is an essential upgrade if you are increasing your turbo.

A: Tuning is not required for BOV's, so you will be just fine to bolt this right up!

Will a Turbosmart Blow-Off or Bypass Valve (BOV/BPV) damage my engine? The simple answer is NO! A Turbosmart BOV or BPV are designed and engineered to improve the performance of your turbocharger system and NOT damage your engine.

Performance-wise, BOVs can have a slight negative affect in applications such as drifting. When you're on and off the throttle all the time, releasing all the charged air can hurt throttle response and give some lag.

You can't put a blow off valve on a naturally aspirated car because induction (the sucking of air into the engine) is done using vacuum. The engine itself sucks air in, instead of the turbine pushing compressed air in.

Put simply, the easiest way to get any form of turbo flutter in a turbocharged engine is to remove the blow-off valve from your car. Doing this will ensure that the air intake has no smooth way to escape, creating that satisfying noise that we car enthusiasts know and love.

If a car is making a fluttering noise when venting at high rpm and boost, then the BOV isn't doing its job. Contrary to popular belief the noise is actually emitted from the turbo, not the BOV itself.

If it occurs at higher engine loads or boost levels, it can cause premature wear to your turbo. To sum up, a BOV prevents turbo flutter by venting the air pressure that causes surge.

The BOV is a pressure release valve. It's purpose is to release the pressure inside the intercooler and charge piping whenever the throttle is closed. If this pressure were not vented in some way, a shock wave would form and back up into the turbo, causing it to stall. This is very bad for the turbo.

In V configuration engines it is common to see a wastegate for each of the manifold runners, this provides more accurate control over the turbo speed. That's the difference between wastegates and blow off valves.

Where is the best place to put a blow off valve? ›

BOV should be located in trash bin. nothing that can be damaged.

The major concern with this design is its ability to hold up to high horsepower applications. “Anything over 800 horsepower you're going to have a hard time getting a recirculating bypass valve to flow enough air to do the job, so a vent-to-atmosphere blow-off valve is really the only way to go,” says Staggs.

At engine idle

A vented BOV needs to remain shut in idle state to avoid leaking. To make that possible, there is a stainless spring inside the upper BOV housing that holds the piston closed.

Each Blow-off Valve (BOV) or Bypass Valve (BPV) needs to be adjusted to suit the vehicle it is mounted.

It's the BOV that makes the signature turbo sound ("pssst"; "sutututu"), not the wastegate.

External Wastegates are responsible for turbo flutter.

That fluttering sound, which typically occurs when the throttle is suddenly closed, is the sound of the turbo trying to push air into the engine but failing, so the compressor blades 'chop' through the air.

The turbo is powered by the exhaust gases. One side of the turbo is located at the exhaust manifold, the other at the engine's air intake, and it contains two small fans joined by a shaft. As exhaust passes through the turbo, it spins one fan, called the turbine.

The airflow to the intake manifold is low, but the air pressure from the turbo is high. Now this high air pressure should go somewhere, but there is no way to move forward. So this air pressure tries to escape back through the turbo. This process is called “Compressor surge” and we get this “stututututu” sound.

Essentially, the noise is caused by what is known as "reversion". When a turbocharged vehicle builds up boost, and the driver backs off the throttle, the throttle body snaps shut, but the turbo is still spinning, trying to compress air.

You'll be looking at $5-6,000 in parts and labor. Secondly, turbos are not designed to flutter, and only compress air in one direction. Turbo flutter causes a lot of back pressure to go through your turbo, which puts a lot of strain on it.

What is a boost creep? ›

"Boost creep is a condition of rising boost levels past what the predetermined level has been set at.

Surging. Also referred to as turbo bark or chirp, compressor surge occurs when intake air actually reverts back out of the compressor. It's most often experienced when elevated boost is produced and then cut off abruptly (i.e., you lift off the throttle suddenly).

The turbine has exhaust gas that it's trying to use but can't. Since the gas can't go through the throttle, it exits the same way it came in. As it exits, the compressor blades chop through the air. This is what creates the famous “stu-stu-stu” noise.

To keep boost, drive pressure and shaft speed in check, there is no better tool than a wastegate. A device that acts as a bypass valve to bleed off excess pressure, a wastegate can promote not just turbo longevity, but engine longevity as well.

A screamer pipe is a type of exhaust configuration fitted to some automotive turbocharged petrol engines with an external wastegate set-up, which vents the waste exhaust to the atmosphere through a separate un-muffled pipe, rather than back into the main exhaust track. This exhaust setup is known for its loud noise.

Many people upgrade their blow-off valve simply to gain the noise, which, even on a completely stock car is quite easy to achieve. But the main reason to upgrade your BOV would be to improve performance and increase reliability.

$100 to $200: This mid-range price level consists of vented and hybrid blow off valves.

Blow-off valve leaks boost. There are usually three things that lead people to suspect a BOV leak: an audible whooshing sound under boost, the car seems to make less boost pressure or power than it used to, or a smoke/intake pressure test was performed and shows a leak from the BOV.

Blow-off valves, or dump valves, are divisive. The premise is simple. In a turbocharged car, the system builds boost pressure to force extra air into the cylinders. The usual combustion business follows, with a greater amount of fuel/air mixture for bigger explosions and more power.

Ball valves may be the most reliable valve and are commonly used for main water shut offs. Similar to gate valves, ball valves should be all the way open to allow the full flow of water or all the way closed to restrict all water from flowing. The valve is controlled by moving it between 0 and 90 degrees.

Why use a bypass valve? ›

Bypass valves are important in any system through which water or oil is pumped to maintain an even pressure and keep the system operating. Construction equipment in particular relies on bypass valves to relieve pressure build-up.

The wastegate is normally closed, held shut by a spring inside the actuator canister. When preset pressure limits are exceeded, the actuator progressively opens the wastegate, allowing exhaust flow to bypass the turbine, thus regulating manifold boost pressure.

The valve which allows mixture into the cylinder is the inlet valve; the one through which the spent gases escape is the exhaust valve. They are designed to open and close at precise moments, to allow the engine to run efficiently at all speeds.

The plastic PCV cover for the Ford Focus ST and Fusion 2.0T engines comes complete with gasket, PCV, and PCV line completely assembled.

Swapping out your EcoBoost's blow-off valve for an aftermarket piece can benefit in both the performance and durability departments, for a relatively low cost.

Not all turbocharged engines are made for blowoff valves. They might need a bypass (aka diverter or recirculating) valve instead. They both accomplish the same task but there's a big difference in how they do it. The type of engine management your car runs will come into play when choosing a valve.

BOV should be located in trash bin. nothing that can be damaged.

A blowoff valve (BOV) is similar to a wastegate, except it works on the intake side of the turbocharger. Once a certain level of pressure is reached, the inlet air opens a spring, allowing for the intake air downstream of the turbocharger to either vent to the atmosphere or be redirected back into the turbo.

Turbo Wastegates are placed on the exhaust gas side of a turbo system and are used to control turbo speed. Turbo Blow Off Valves are placed on the boost side of the turbo system and are used to vent boost in the intake tube once you let off the gas pedal, to avoid damaging the turbo.

The PCV system allows for cleaner exhaust, prevents blowby at seals and gaskets, removes crankcase gasses generated by the combustion process that will sludge up and destroy the engine if left unchecked, and allows the engine to run more efficiently thus creating better fuel mileage!

Does PCV valve affect idle? ›

A PCV valve that's stuck open will allow too much air to enter the intake manifold, leading to a leaner idling fuel-air mixture. Stuck closed leads to a build up of pressure in the crank case which creates a variety of oil leaks! And this in turn can lead to a range of issues, including a rough idle.

However, failing due to closed throttle. Therefore, it dramatically increases the load on the bearings of the turbo. If it occurs at higher engine loads or boost levels, it can cause premature wear to your turbo. To sum up, a BOV prevents turbo flutter by venting the air pressure that causes surge.

A blow-off valve is a version of a compressor bypass valve that vents to atmosphere. There is no performance reason for doing this, but it does make a really loud noise. The only performance-related reasons to upgrade the compressor bypass valve is to fix a leaky factory valve.

If a car is making a fluttering noise when venting at high rpm and boost, then the BOV isn't doing its job. Contrary to popular belief the noise is actually emitted from the turbo, not the BOV itself.

Installation is usually made easy, and it goes without saying that our upgraded boost bypass valves are also made of higher quality material. Not to mention the feeling that your turbo is not only optimally protected, but also that the power is noticeable again.

The airflow to the intake manifold is low, but the air pressure from the turbo is high. Now this high air pressure should go somewhere, but there is no way to move forward. So this air pressure tries to escape back through the turbo. This process is called “Compressor surge” and we get this “stututututu” sound.