How much back pressure does a turbo create?

“26 psi of exhaust back pressure (measured at the exhaust housing),” Pre turbo and post turbo back pressure can be influnced by different things.

Do you need back pressure with a turbo?

On a turbo car, the heat of the spent combustion gas along with the exhaust gas back pressure in the exhaust manifold are responsible for spinning the turbine. So you need back pressure in the exhaust manifold. Where you want to minimize back pressure is in the exhaust after the turbine (from the DP’s on to the tips).

What is back pressure in a car?

Definition. Engine exhaust back pressure is defined as the exhaust gas pressure that is produced by the engine to overcome the hydraulic resistance of the exhaust system in order to discharge the gases into the atmosphere.

How much is too much back pressure?

For most of its engines, GM recommends no more than 8.62 kPa (1.25 psi) at idle, and no more than 20.68 kPa (3 psi) at 2,000 rpm.

What happens if a motor has too much back pressure?

The classic symptoms of too much backpressure include things like a lack of high speed power, poor fuel economy and even overheating. Anything that backs up exhaust pressure into the engine will also back up heat.

Does backpressure make more horsepower?

Though if you ask a forum poster to explain this, you’ll likely end up with an even foggier understanding of the science. Thankfully, Jason Fenske of YouTube’s Engineering Explained is here to set the record straight. As it turns out, backpressure is simply bad for power output.

What is a good back pressure reading?

With the engine idling at normal operating temperature, read the gauge to determine the back pressure. The reading should not exceed 1-1/4 PSI. If the reading exceeds 1-1/4 PSI, the vehicle has restricted exhaust.

How do you calculate pressure ratio on a turbo?

Calculating Pressure Ratio (PR= P2c / P1c) Pressure ratio is a variable equation that combines ambient pressure with gauge pressure divided by ambient pressure. This identifies where the compressor will perform its max duty cycle. Knowing pressure ratio is a key component to selecting the correct turbo for your application.

How does back pressure affect turbos?

With back pressure, exhaust gases cannot easily flow in the exhaust system. Which means they will spool the turbo with reduced force – resulting in power loss and more turbo lag. Now that’s out of the way, let’s get into the details of back pressure and turbos.

What is back pressure in an exhaust system?

Back pressure refers to the air pressure in the exhaust system. After the discussion above, we now understand that back pressure should be kept as low as possible, so exhaust gases can flow easily. Is Back Pressure Good Or Bad? So is back pressure always bad? The answer is yes. You want to keep back pressure as low as possible.

How much psig do you need for a turbo to work?

This turbo has a max flow of 80 lbs/min at 1.95 PR, whereas 3.0 PR can flow 95 lbs/min. In order to reach the 3.0 pressure ratio, you would need ~26 PSIg at sea level. This is not an option for our example since we are limited to 12 PSIg due to our stock engine internals and pump gas fuel.