What does the 0.55 A/R ratio mean for my turbo?

The 0.55 A/R ratio on this turbine housing affects how quickly your turbocharger spools up. A smaller A/R like this generally leads to faster boost response at lower RPMs, while larger ratios favor higher RPM power.

What type of flange does this housing use?

This turbine housing uses a T25/5-bolt flange. This is a common mounting pattern that allows it to be used with many Garrett turbochargers and other compatible turbo setups.

Does this kit include everything needed for wastegate control?

Yes, this assembly kit includes the wastegate actuator. This means you get the turbine housing and the necessary component for controlling boost pressure in one package.

Garrett GBC20-300 0.55 A/R Turbine Housing 827690-0012

Name: Garrett GBC20-300 0.55 A/R O/V T25/5-Bolt Turbine Housing Wastegate Assembly Kit
Brand: Garrett
SKU: garrett-garrett-gbc20-300-0-55-a-r-o-v-t25-5-bolt-turbine-housing-wastegate-asse-t14-710061
Price: 233.42 USD
Availability: BackOrder

Garrett GBC20-300 0.55 A/R O/V T25/5-Bolt Turbine Housing Wastegate Assembly Kit

$233.42

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Garrett GBC20-300 turbine housing with 0.55 A/R and T25/5-bolt flange. Not CARB approved.

Key Features

This turbine housing has a 0.55 A/R ratio for balanced spool and top-end power.
Features a T25/5-bolt turbine inlet flange for broad compatibility.
Constructed from durable cast iron to handle high temperatures and pressures.
Includes a wastegate actuator for integrated boost control.
Not CARB approved; cannot be shipped to California.

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Product Details

This Garrett GBC20-300 turbine housing features a 0.55 A/R ratio and a T25/5-bolt turbine inlet flange. The A/R ratio, which measures the volute area relative to its radius, influences how quickly the turbocharger spools up and how much top-end power it can make. A 0.55 A/R is a good balance for many applications, offering quicker response than larger housings without sacrificing too much high-RPM flow.

Built with durable cast iron, this housing is designed to withstand the high temperatures and pressures found in forced induction systems. The T25/5-bolt flange is a common size, making it compatible with a range of Garrett turbochargers and aftermarket setups. This assembly includes the wastegate actuator, simplifying installation and ensuring proper boost control for your engine.

Please note that this part is not CARB approved and cannot be shipped to California. Always consult your vehicle's service manual or a qualified mechanic for specific installation procedures and compatibility with your engine build.