Negative boost readings are vacuum. Thats the amount of air the engine is pulling out of the intake system. Boost is the amount of positive pressure above atmospheric conditions, vacuum is the amount of negative pressure below atmospheric conditions. Every machines a smoke machine if you operate it wrong enough.

What causes boost to drop?

So basically, the term boost refers to the pressurized buildup of extra air that the engine is not using. If your turbo cannot provide enough extra air at the high RPMs because the engine needs more air, then your boost will drop.

Why do you need a boost gauge?

A boost gauge is used to ensure excessive pressure is not being generated when boost pressure is being modified to levels higher than OEM standard on a production turbocharged car. A boost gauge will measure pressure in either psi or bar; many also measure manifold vacuum pressure in inches of mercury (in.

Why is boost negative at idle?

When the engine is running, its sucking air from the intake manifold, causing a negative pressure. The difference is that under a load demand, the turbo can push more air into the manifold causing the pressure to cross over 0 to be a positive number, which is under boost.

What causes a turbo not to boost?

If a turbocharger doesnt produce enough boost pressure, it wont work. Low pressure can also be caused by leaking lines or gaskets (allowing pressure to escape before driving air into the cylinders, improper filter maintenance, and a worn or sticky poppet valve can also cause this condition.

What does boost Cut feel like?

Boost cut can feel just like fuel cut, IMO, or it can feel like a lighter episode of fuel cut. The EXPERIENCE can easily be misinterpreted as fuel/boost cut, when in reality, its Knock Retard. They all can occur under similar conditions, and - I believe - can even occur at the same time, masking eachother.

How much boost is safe?

If you have a stock engine, with a compressor that is factory set to produce no more than twenty pounds of boost, you shouldnt modify the system to make it produce much more than 25 pounds of boost. And increase of 5 pounds over stock is probably the limit you should go by.

Does a turbo run at idle?

While engines usually have an rpm limit of 5,000 - 7,000 rpm, turbos spin at up to 150,000 rpm! In turbo-charged cars without intercoolers, temperatures can shoot over 150 degrees C.

How do you know when your turbo is not working properly?

The symptoms of a damaged or failing turbo are:Loss of power.Slower, louder acceleration.Difficulty maintaining high speeds.Blue/grey smoke coming from the exhaust.Engine dashboard light is showing.

How does boost cut work?

Boost cut is where you limit the amount of boost your compressor makes by leaking exhaust through the waste gate to slow down the compressor wheel. Fuel cut where the ECU sees 1500hz from the air meter (Karman wave style) and stops the injectors from adding more fuel, to stop the level of boost you have.

What is considered a lot of boost?

You can run as much boost as the tune will handle. Most on here consider 15-18lbs low boost and anything over 26psi high boost, however if the tune is off you can damage the motor at any boost level.