What does a r mean on turbo?

A/R stands for Area over Radius. It is defined as the inlet (or, for compressor housings, the discharge) cross-sectional area divided by the radius from the turbo centerline to the centroid of that area.

How does AR affect turbo?

Aspect Ratio (AR) is commonly used to indicate a turbocharger housing size. The Aspect Ratio (AR) is the ratio of the area of the exhaust turbine inlet to the radius from the turbine impeller center. The AR ratio should remain the same as the Volute gets smaller as it gets closer to the impeller.

Do smaller turbos spool faster?

Smaller turbos spool up much faster than a single large turbocharger. Manufacturers may also use strategies such as using a small and a big turbo at the same time. The small unit spools up faster for low to moderate speeds, while the larger turbo kicks in at very high speeds.

What is the exhaust housing on a turbo?

Turbine housing– collects exhaust gasses from an engine and directs it through a volute (passage) which drives the shaft wheel assembly of a turbo causing it to spin. Turbine housings are also referred to as the “hot side” of the turbo because of its continuous exposure to hot exhaust gas.

What size turbo should I run?

The calculation is simple: Divide the absolute outlet pressure that you think you want (14.7 + boost pressure) by the absolute inlet pressure that the Earth says you can have (14.7) and you've got your pressure ratio. Limiting yourself to a reasonable number is the hardest part.

Turbine housing A/R's explained

What does T4 mean turbo?

T4 turbos are usually for larger motors and use a different exhaust flange. T4's can deliver enough air for applications in the 400 to 800HP range. T4's have been very popular in full tilt 2.5+L Subaru setups to make loads of horsepower.

What RPM does turbo Kick?

While your car's engine revs, at cruise, at around 2,000 rpm, a turbo's turbine can reach rotational speeds of more than 280,000 rpm.

What size turbo is a GT45?

The cold side of DNA's GT45 clone turbo featured a 0.66 A/R, a 69mm inducer, and a 98mm exducer. The hot side included an 88mm inducer, a 77.5mm exducer, and 1.05 A/R.

How do you calculate corrected air flow?

We begin with the compressible mass flow equation and, using algebra, we divide both sides of the equation by the area, multiply both sides by the square root of the total temperature, and divide both sides by the total pressure. The corrected weight flow per unit area is just a function of the Mach number.

How much boost does a turbo make?

The typical boost provided by a turbocharger is 6 to 8 pounds per square inch (psi). Since normal atmospheric pressure is 14.7 psi at sea level, you can see that you are getting about 50 percent more air into the engine. Therefore, you would expect to get 50 percent more power.

What do Garrett turbo numbers mean?

GT simply stands for “Garrett Turbo” 25 refers to the “frame size” of the turbo, based on the turbine wheel inducer (the inducer being the top of the blade). 60 refers to the compressor exducer size, in millimeters, of the compressor wheel.

What do turbo size numbers mean?

A turbocharger's A/R (aspect ratio) typically is the number that is cast into an exhaust-turbine housing that identifies the size of the housing, from the inlet to the radius from the center of the turbine wheel. Basically, the larger the number, the bigger the housing.

What size turbo is on a 7.3 Powerstroke?

7.3L Power Stroke

The GTP38R turbocharger contains an exclusive ball bearing cartridge for unbeatable response, efficiency, and durability. Elimination of thrust bearing eliminates Failures at elevated boost levels. The 88mm GT compressor wheel provides 33% more flow than the stock 80mm wheel.

Why is my turbo hissing?

Turbo whistle is the sound of the compressor inside the turbocharger speeding up (also known as 'spooling up', which is why it kicks in at the boost threshold (when the turbo starts to kick in) as you accelerate up the rev range.

What does a failing turbo sound like?

Loud noises: If your vehicle has a bad turbo, you may hear loud noises that sound like whining or screeching. So if your vehicle is running and you hear a loud whining sound that increases in volume as the problem goes unfixed, this is most likely to do a turbo problem.

How do you stop turbo lag?

Does turbo save fuel?

Are turbocharged engines more fuel-efficient than naturally aspirated engines? In theory, turbochargers can boost the efficiency of an internal combustion engine by anywhere from 10 to 30 percent.

How does turbo lag feel?

What does turbo lag feel like? If you put your foot down on the accelerator of a turbocharged vehicle, you may experience a noticeable gap before your car begins to accelerate quickly. When the turbo kicks in, you'll feel a significant jump in acceleration.

What's better T3 or T4 turbo?

In general, T3 class turbos can deliver air volume for applications in the 200 to 300 HP range. On the other hand, the T4 turbo has a larger turbine on the exhaust side and larger turbine fins on the intake compressor side. This means that T4 can generate more air at full boost to achieve more horsepower than T3.

How much HP can a T3 T4 turbo make?

The high-boost turbo is designed to spool fairly quickly and can support up to 500 horsepower.