Which blow off valve flutters?

Asked by: Mr. Brown Bahringer DVM
Score: 4.2/5 (57 votes)

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.

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Likewise, Why does my blow-off valve flutter?

The flutter sound is caused by a blow off valve that reacts too slow and usually facilitates compressor surge.

Then, Can you have turbo flutter with a blow-off valve?. Almost every vehicle with a turbo comes with a blow-off valve, and if it's working properly, you won't get any significant turbo flutter.

Also asked, Does HKS BOV flutter?

The HKS SSQV is s perfectly fine BOV. Low boost it sounds like it flutters, but thats just how they sound when its low boost. But WOT it should be the signature sound or if recirculated like it should be with DSMs unless running blowthrough, it shouldn't flutter.

Is BOV flutter bad?

Unlike actual turbo flutter, this sound isn't indicative of any kind of harsh or overly heavy use for your engine. If this is the noise that you associate as turbo flutter, then you're in luck. Blow off release isn't harmful to your engine or turbocharger in any way.

28 related questions found

Does turbo flutter ruin your turbo?

When the compressed air has nowhere to go, it causes the turbo rotational speed to rapidly drop, and attempts to push against the wheel. This can cause premature wear on your turbo, however closed throttle flutter on modern turbochargers is unlikely to cause a noticeable drop in turbocharger lifespan.

How much does a turbo flutter cost?

The price of a turbocharger typically starts from $400 and goes up depending on the make and model of your car. For smaller cars such as an Audi A4, or a Subaru Impreza you can expect to pay less for a replacement turbocharger.

Can you change the sound of a BOV?

Vent to the Atmosphere

The easiest way to obtain a more noticeable sound is by installing a blow-off valve designed to vent directly to the atmosphere. Airflow is vented directly to the engine bay with no intake tubing or air boxes to muffle the sound, resulting in a far louder discharge.

How do you slow a turbo flutter?

Build boost then jump off with no bov or too small a bov and ya get a quick flutter.. same setup build up boost then take your foot off the throttle half as quick and you can make the flutter slower. Even pausing half way thru your throttle release can cause it to flutter pause then start fluttering again.

Are blow off valves illegal?

A blowoff valve (sometimes "hooter valve" or BOV) performs the same task but releases the air into the atmosphere instead of recirculating it. ... Motorsports governed by the FIA have made it illegal to vent unmuffled blowoff valves to the atmosphere.

Why do turbos flutter?

When you're flat out and your turbocharged engine is producing peak boost, you have fast airflow at high pressure traveling through your intake system after the turbo compressor. ... The fluttering you hear is the air escaping back through the turbo as the compressor wheel fights this motion.

Does a BOV add HP?

The MS3's bov leaks at stock boost levels. Going aftermarket does not add any more power, but stops the loss of power due to the leak. This is not the case on our cars.

Do Turbos need blow off valves?

1. Cars don't have blow-off valves from the factory, so I don't need one. ... Today, most modern turbocharged cars do have a blow-off valve from the factory. However, it recirculates the vented air, so it doesn't give the characteristic sound of a vent-to-atmosphere blow-off valve.

Can a blow off valve damage your 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.

Are blow off valves illegal in California?

blow off valves are not illegal! ( if your car came with one) provided it is used in accordance with state smog laws, and per manufacturers specifications. ie: if it is recirculated in to the intake it must remain so.

What causes turbo flutters?

Turbo flutter, also known as compressor surge, occurs when there is an abundance of pressurized air in the turbo system. When the engine is not able to combust the full amount of air pressurized by the turbocharger, this excess air will build up in the intercooler system.

Why does my turbo flutter when I accelerate?

When your turbocharged engine is under load, the engine is consuming air (airflow), and your turbo is creating pressure (boost). ... That fluttering noise is the sound of a turbo operating in compressor surge, as the compressor 'chops' through the air rather than pushing the air into the engine.

What does a bad turbo sound like?

5) Siren noise

A faulty turbo may result in a loud, siren sound coming from the engine. The louder the sound, the worse the problem could be. Here's the siren noise that typically results from a failing turbo. If you hear this noise, you should consult your mechanic as soon as possible to get your vehicle checked.

Do Wastegates make a sound?

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. You can read more about this phenomenon here.

How many miles do Turbos last?

Turbos are designed to last the lifetime of the vehicle (or around 150,000 miles); however, it's possible for them to wear out over time depending on how hard you drive the car and the original build quality of the turbo.

Do turbos shorten engine life?

2. Turbos Reduce the Lifespan of an Engine. One of the most common turbo myths is that running boost will damage your engine over time. ... However, a properly implemented turbo pushing enough PSI through a motor to produce respectable levels of power won't strain a motor any more than idling in traffic will.

Why are turbo engines bad?

Smaller engines use less fuel, but being turbocharged adds pressure, which can lead to higher temps and engine knock, damaging the engine. ... So when you ask for full power, turbocharged engines aren't as efficient because of the high fuel to air mixture that's needed to protect the engine.

Can a turbo spin backwards?

There is a common belief that compressor surge can cause the turbo to “stall” (i.e. stop spinning), or even spin backwards. It's worth clearing the air and saying that this is incorrect – the turbo will never stop dead or reverse direction because of compressor surge.