44mm vs. 50mm vs. 60mm Wastegate: What Size Granatelli Wastegate Do You Need?

Choosing the correct external wastegate is one of the most important parts of building a turbo system.

Too small and the system may struggle to bypass enough exhaust to control boost. Too large usually will not hurt boost control, but it can add unnecessary size, weight and packaging difficulty.

Granatelli Motor Sports offers external wastegates in 44mm, 50mm and 60mm sizes, with both piston-actuated and water-cooled diaphragm designs.

So which size is right for your build?

The answer depends on more than horsepower. Turbo size, engine displacement, target boost, manifold design, exhaust flow and wastegate placement all affect how much wastegate flow a turbo system actually needs.

Granatelli Wastegate Size Quick Guide

The horsepower ranges below are intended as a general starting point for typical gasoline performance builds. They are not maximum horsepower ratings for the wastegates.

Wastegate Size	Practical HP Starting Range	Typical Use
44mm	Approximately 350–700 HP	Street turbo builds, compact installations, moderate horsepower
50mm	Approximately 600–1,000 HP	Larger street/strip turbo systems and higher exhaust-flow combinations
60mm	Approximately 900–1,500+ HP	Large-frame turbos, big-displacement engines and serious race combinations

Important: These are sizing guidelines, not horsepower limits. A 44mm wastegate can control considerably more horsepower in the right combination, while a lower-horsepower engine may require a larger wastegate if it needs to bypass a large amount of exhaust.

Horsepower Is Not the Only Factor

This is one of the biggest misconceptions about external wastegate sizing.

You cannot simply say:

"My engine makes 800 horsepower, so I need a certain size wastegate."

Wastegate sizing is based on how much exhaust must be diverted around the turbocharger turbine to maintain the desired boost pressure.

Important factors include:

• Engine displacement
• Turbocharger size
• Target horsepower
• Target boost pressure
• Turbine housing size
• Exhaust manifold design
• Wastegate location
• Single or twin turbo configuration
• Single or dual wastegates
• Exhaust backpressure

A Lower-Boost Engine Can Actually Need a Larger Wastegate

This sounds backwards at first, but it is important.

If you have a large turbocharger capable of making much more boost than you actually want, the wastegate has to bypass a significant amount of exhaust around the turbine.

For example, a large-displacement V8 trying to run relatively low boost may require more wastegate flow than another engine making more horsepower at higher boost.

That is why wastegate sizing should not be based on horsepower alone.

Granatelli 44mm Wastegates

The Granatelli 44mm external wastegate is the compact option in the Granatelli lineup.

Granatelli describes the 44mm size as a strong choice for many single-turbo and twin-turbo street builds where packaging space is important and a larger 50mm or 60mm gate is not required.

For many typical street turbo combinations, we would consider the 44mm a strong starting point in approximately the 350–700 horsepower range.

Again, that is not a maximum horsepower rating.

A properly designed system using a 44mm wastegate can control considerably more power, especially when multiple wastegates are used.

44mm Is a Good Choice For:

• Street turbo builds
• Moderate-horsepower applications
• Tight engine bays
• Compact turbo manifolds
• Single-turbo street cars
• Twin-turbo systems using one gate per bank
• Street/strip applications

Granatelli 44mm Piston Wastegate – 540261

The Granatelli 540261 combines a compact 44mm valve with a piston-actuated boost-control design.

Features include:

• 44mm valve
• Piston actuation
• Black anodized billet aluminum top cap
• Stainless-steel base
• V-band inlet and outlet
• Five variable-rate springs

View the Granatelli 44mm Piston Wastegate – 540261

Granatelli 44mm Water-Cooled Wastegate – 540244

For builders who prefer a traditional diaphragm-style actuator, Granatelli also offers the 540244 44mm water-cooled diaphragm wastegate.

The water-cooled actuator helps manage temperature in installations where the wastegate is positioned close to turbochargers, manifolds and other high-temperature exhaust components.

View the Granatelli 44mm Water-Cooled Wastegate – 540244

Granatelli 50mm Wastegates

The 50mm wastegate is the middle ground in the Granatelli lineup.

It offers more exhaust bypass capacity than the compact 44mm without taking up as much room as a large 60mm gate.

Granatelli specifically describes its 50mm wastegate as a good match for turbo systems that need more exhaust bypass capacity than a 44mm gate.

For a typical performance gasoline application, the 50mm size is a strong starting point for approximately 600–1,000 horsepower.

50mm Is a Good Choice For:

• High-horsepower street cars
• Street/strip turbo builds
• Larger turbochargers
• Higher exhaust-flow combinations
• Turbo LS builds
• Turbo Coyote builds
• Turbo HEMI builds
• Drag racing applications

Granatelli 50mm Piston Wastegate – 540203

The Granatelli 540203 is a 50mm piston-actuated external wastegate designed for demanding street, street/strip, drag racing and performance turbo applications.

It provides more bypass capacity than the 44mm piston gate while retaining the Granatelli piston-actuated design.

• 50mm valve
• Piston actuation
• Cast stainless-steel base
• Black anodized aluminum top cap
• V-band mounting
• Five-spring tuning kit

View the Granatelli 50mm Piston Wastegate – 540203

Granatelli 50mm Water-Cooled Wastegate – 540202

The Granatelli 540202 combines a 50mm high-flow valve with a water-cooled diaphragm actuator.

This gives builders additional exhaust bypass capability while helping control actuator temperatures in high-heat applications.

• 50mm valve
• Diaphragm actuation
• Water-cooled actuator housing
• Black anodized billet aluminum top
• Stainless-steel base
• V-band flanges and clamps
• Multi-spring tuning kit

View the Granatelli 50mm Water-Cooled Wastegate – 540202

Granatelli 60mm Wastegates

The 60mm external wastegate is the largest size in the current Granatelli lineup.

Granatelli designed the 60mm options for large turbocharger systems and high-exhaust-flow combinations that require substantial bypass capacity.

For large gasoline performance applications, the 60mm becomes a strong starting point around the 900–1,500+ horsepower range.

But horsepower alone still does not determine whether you need a 60mm wastegate.

A large-displacement engine with a large turbo running low boost may benefit from a 60mm gate even at a lower horsepower level because the wastegate has to bypass more exhaust.

60mm Is a Good Choice For:

• Large-frame turbochargers
• Big-displacement engines
• High-horsepower V8 turbo builds
• Drag racing
• Large single-turbo combinations
• Low-boost large-turbo combinations
• High-exhaust-flow engines
• Performance diesel applications
• 1,000+ horsepower builds

Granatelli 60mm Piston Wastegate – 540260

The Granatelli 540260 60mm piston wastegate is designed for large turbocharger systems and high-exhaust-flow combinations.

The large 60mm valve gives the exhaust significantly more bypass capacity when precise boost control requires moving a large amount of exhaust around the turbine.

View the Granatelli 60mm Piston Wastegate – 540260

Granatelli 60mm Water-Cooled Wastegate – 540259

The Granatelli 540259 combines the large 60mm valve with a water-cooled diaphragm actuator.

It is designed for high-horsepower, racing and high-temperature turbo systems where maximum exhaust bypass capacity and actuator heat management are important.

The wastegate also includes V-band inlet and outlet hardware and a multi-spring kit for configuring base boost pressure.

View the Granatelli 60mm Water-Cooled Wastegate – 540259

44mm vs. 50mm vs. 60mm Granatelli Wastegate

Size	General HP Starting Point	Main Advantage	Typical Build
44mm	350–700 HP	Compact packaging	Street / moderate turbo build
50mm	600–1,000 HP	Balance of flow and size	High-performance street / street-strip
60mm	900–1,500+ HP	Maximum exhaust bypass capacity	Large turbo / race / big-displacement

What About Twin-Turbo Engines?

Twin-turbo systems change the calculation.

Instead of using one large wastegate, many twin-turbo systems use one wastegate for each turbocharger or each exhaust bank.

For example, a high-horsepower twin-turbo V8 may use two 44mm wastegates instead of one 60mm wastegate.

This can provide excellent boost control because each gate only has to manage the exhaust flow from its portion of the engine.

Two 44mm Wastegates vs. One 60mm Wastegate

This is another reason horsepower ratings can be misleading.

A 1,000+ horsepower twin-turbo engine using two properly positioned 44mm wastegates may have excellent boost control.

Meanwhile, a large-displacement single-turbo engine attempting to run very low boost could require a single 60mm gate.

The system design matters just as much as the horsepower number.

Does Wastegate Location Matter?

Absolutely.

A large wastegate installed in a poor location may flow less effectively than a smaller gate positioned correctly.

The wastegate should receive a smooth path of exhaust flow from the manifold.

A sharp 90-degree connection can make it much harder for exhaust to enter the wastegate.

Turbocharger manufacturer Garrett notes that poor manifold orientation can reduce effective wastegate flow dramatically.

This can lead to boost-control problems even when the wastegate itself appears large enough.

What Is Boost Creep?

Boost creep occurs when boost pressure continues climbing above the intended target even though the wastegate is open.

Possible causes include:

• Wastegate too small
• Poor wastegate placement
• Restrictive wastegate plumbing
• Large engine displacement
• Large turbocharger
• Low target boost
• High exhaust flow
• Poor manifold design

Simply changing the wastegate spring will not necessarily fix boost creep if the system cannot physically bypass enough exhaust.

Does Wastegate Spring Pressure Determine Maximum Boost?

The spring primarily establishes the mechanical base boost pressure.

A boost controller can generally be used to command additional boost above the base spring pressure, depending on the configuration.

The spring does not determine how much horsepower the wastegate can support.

Piston or Water-Cooled Diaphragm?

Granatelli offers both designs in the 44mm, 50mm and 60mm range.

Granatelli Piston Wastegate

The piston-actuated design eliminates the traditional flexible diaphragm and uses mechanical piston actuation.

It is a strong option for:

• High-heat turbo systems
• Street/strip vehicles
• Drag racing
• Builders who prefer piston-style boost control

Granatelli Water-Cooled Diaphragm Wastegate

The water-cooled diaphragm design uses coolant circulation around the actuator housing to help manage temperature.

It can be especially useful when:

• The wastegate is close to the turbocharger
• Engine-bay temperatures are extremely high
• The vehicle sees extended hard operation
• Thermal stability is important

Which Granatelli Wastegate Should You Choose?

Choose a 44mm Wastegate If:

• You have a typical street turbo build
• Packaging space is limited
• You are approximately in the 350–700 HP range
• You are using twin wastegates
• Your combination does not require massive exhaust bypass flow

Choose a 50mm Wastegate If:

• You have a larger turbocharger
• You are approximately in the 600–1,000 HP range
• You need more bypass capacity than a 44mm
• You want a balance between compact size and high flow
• You have a serious street/strip build

Choose a 60mm Wastegate If:

• You are building a 900–1,500+ HP combination
• You have a large-frame turbocharger
• You have a large-displacement engine
• You are trying to control relatively low boost with a large turbo
• Your engine produces very high exhaust flow
• You want maximum external wastegate bypass capacity

The Bottom Line

When choosing between a 44mm, 50mm and 60mm Granatelli wastegate, horsepower is a useful starting point — but it should never be the only factor.

As a simple starting guide:

• 44mm: approximately 350–700 HP
• 50mm: approximately 600–1,000 HP
• 60mm: approximately 900–1,500+ HP

But the correct wastegate ultimately depends on engine displacement, turbo size, desired boost, exhaust flow, manifold design and wastegate placement.

A properly placed 44mm wastegate can control an impressive amount of power, while a large-displacement low-boost engine may require a 60mm wastegate at a lower horsepower level.

The goal is not to install the biggest wastegate possible.

The goal is to install the right amount of exhaust bypass capacity for the turbo system.

Shop Granatelli External Wastegates

Granatelli Motor Sports offers 44mm, 50mm and 60mm external wastegates in piston-actuated and water-cooled diaphragm configurations.

Shop All Granatelli Motor Sports Wastegates