Rennen Plus

Individual Throttle Bodies (ITB) Upgrade - 3 Stud Inlet Manifold

Transform the character, responsiveness and visual appeal of your air-cooled Porsche with the Rennen by JSR Individual Roller Barelle Throttle Bodies (ITB) Upgrade for the Porsche 964 3.6ltr engine. Finished in a striking gunmetal coating and supplied with silver velocity stacks, classic mesh air filters, fuel rails machined for EV6 injectors and a precision-engineered mechanical throttle linkage system, this package delivers a perfect blend of motorsport-inspired performance and timeless Porsche styling.

Fits:

• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

Unlike conventional butterfly throttle body systems, Roller Barrel Throttle Bodies utilise a rotating barrel mechanism that provides an unobstructed airflow path at wide-open throttle. This design has its roots in top-level motorsport and is widely regarded as one of the most responsive and visually impressive induction systems available for naturally aspirated engines.

For Porsche enthusiasts seeking the ultimate driving experience, the Rennen by JSR Roller Barrel ITB system offers a combination of performance, sound and aesthetics that transforms the character of the Porsche 964 3.6ltr

What Makes Roller Barrel Throttle Bodies Special?

Traditional throttle bodies use butterfly plates that partially obstruct airflow even when fully open. Roller Barrel Throttle Bodies utilise a cylindrical rotating barrel that creates a straighter and less restrictive airflow path.

The result is:

• Exceptional throttle response
• Improved airflow efficiency
• Reduced airflow turbulence
• Enhanced engine breathing
• Increased performance potential
• Smoother airflow characteristics
• Motorsport-inspired induction technology

Roller barrel systems are renowned for delivering an incredibly direct connection between throttle input and engine response.

Why Upgrade to Individual Roller Barrel Throttle Bodies?

The Porsche 964's air-cooled flat-six engine responds exceptionally well to individual throttle body induction systems.

With each cylinder receiving its own dedicated airflow source, engine responsiveness is transformed.

Benefits include:

• Instant throttle response
• Sharper acceleration feel
• Improved airflow distribution
• Increased induction efficiency
• Enhanced engine character
• Greater tuning flexibility
• Improved driver engagement
• Distinctive motorsport induction sound

The combination of Roller Barrel technology and individual throttle bodies creates one of the most desirable induction upgrades available for the Porsche 964 platform.

Motorsport Styling with Premium Engineering

The Rennen by JSR Roller Barrel ITB package is designed to look as impressive as it performs.

Featuring:

• Premium gunmetal-finished throttle bodies
• Silver velocity stacks
• Classic mesh air filters
• Precision mechanical throttle linkage

The result is a visually stunning engine bay that captures the appearance of classic Porsche race engines while incorporating modern engineering and manufacturing standards.

Mechanical Throttle Linkage for Maximum Driver Engagement

Included with the system is a precision-engineered mechanical throttle linkage assembly.

Unlike electronic (drive by wire) throttle systems, the mechanical linkage provides:

• Direct throttle actuation
• Exceptional pedal feel
• Immediate engine response
• Accurate throttle modulation
• Pure analogue driving feedback
• Motorsport-inspired control

This direct mechanical connection is a key element of the driving experience and one of the reasons enthusiasts favour traditional ITB systems.

Crankshaft Position Sensor Mounting Bracket for ITB Conversions

The Rennen Crankshaft Position Sensor Mounting Bracket is a precision-engineered component developed specifically for Porsche 911 and Porsche 964 Individual Throttle Body (ITB) conversions. Designed to provide accurate and stable mounting of the crankshaft position sensor, this bracket enables modern engine management systems to monitor crankshaft position and engine speed with exceptional precision.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

As Porsche performance builds increasingly adopt standalone ECUs and modern EFI systems, accurate crankshaft position data has become essential for reliable ignition timing, fuel delivery and engine synchronisation. The Rennen by JSR mounting bracket ensures the crankshaft sensor remains securely positioned in relation to the trigger wheel, providing a clean and consistent signal under all operating conditions.

Whether building a fast-road Porsche, a high-performance air-cooled engine or a dedicated motorsport application, this bracket forms a critical part of a professional EFI and ITB conversion.

What Does a Crankshaft Position Sensor Mounting Bracket Do?

The crankshaft position sensor mounting bracket securely locates the crankshaft sensor in the correct position relative to the trigger wheel mounted on the engine.

This allows the ECU to accurately monitor:

• Crankshaft position Engine speed (RPM)
• Ignition timing reference
• Fuel injection timing
• Engine synchronisation
• Advanced ECU control functions

A stable and accurately positioned sensor is critical for reliable engine operation and precise ECU calibration.

Why Is a Crankshaft Position Sensor Important?

The crankshaft position sensor is one of the most important inputs used by a modern engine management system.

Without an accurate crankshaft signal, the ECU cannot reliably control ignition or fuel delivery.

Benefits of accurate crankshaft position monitoring include:

• Precise ignition timing
• Accurate fuel injection control
• Stable engine operation
• Improved starting performance
• Enhanced throttle response
• Greater tuning flexibility
• Improved engine efficiency
• Reliable high-RPM performance

For performance-oriented Porsche engine builds, accurate crankshaft data forms the foundation of effective ECU control and engine tuning.

Why Is an ITB Upgrade So Appealing?

Individual Throttle Body systems are widely regarded as one of the most exciting naturally aspirated performance upgrades available for Porsche engines.

By providing each cylinder with its own dedicated throttle body, airflow restrictions are reduced and throttle response is dramatically improved.

Benefits of a Rennen by JSR ITB conversion include:

• Immediate throttle response
• Improved airflow efficiency
• Enhanced engine breathing
• Increased performance potential
• Greater tuning flexibility
• Distinctive induction sound
• Motorsport-inspired engine character
• Increased driver engagement

When paired with modern EFI and engine management systems, ITBs offer a unique blend of classic Porsche character and modern performance technology.

Why Choose the Rennen by JSR Crank Sensor Bracket?

A precision-engineered crankshaft sensor mounting solution is essential for reliable ECU operation.

Benefits include:

• Accurate sensor positioning
• Stable trigger wheel alignment
• Consistent ECU signal quality
• Improved ignition timing accuracy
• Enhanced engine management reliability
• Professional EFI conversion installation
• Suitable for road and motorsport applications
• Supports advanced engine tuning strategies       

Cam Position Sensor Mounting Bracket for ITB Conversions

The Rennen Cam Position Sensor Mounting Bracket is a precision-engineered component designed specifically for Porsche 911 and Porsche 964 Individual Throttle Body (ITB) conversions. Developed to provide a secure and accurate mounting location for a cam position sensor, this bracket enables modern engine management systems to utilise camshaft position data for improved ignition timing, fuel delivery and overall engine control.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

As Porsche enthusiasts increasingly move towards advanced EFI and standalone ECU systems, accurate engine position monitoring becomes critical. The cam position sensor mounting bracket provides the stability and precision required to ensure reliable sensor operation in both high-performance road and motorsport applications.

Designed to integrate seamlessly with Rennen by JSR ITB systems, this bracket helps unlock the full potential of modern engine management while preserving the character of the classic air-cooled Porsche engine.

What Does a Cam Position Sensor Mounting Bracket Do?

The mounting bracket securely positions the camshaft position sensor relative to the engine's camshaft trigger reference point.

This allows the ECU to accurately determine camshaft position and synchronise critical engine functions, including:

• Sequential fuel injection
• Sequential ignition control
• Accurate engine timing calculation
• Cylinder identification
• Advanced ECU tuning strategies
• Improved engine management precision

Without a stable and accurately positioned sensor mount, the ECU may struggle to maintain consistent timing and engine synchronisation.

Why Is a Cam Position Sensor Important?

Modern engine management systems rely on precise engine position information to optimise performance.

Cam position data helps provide:

• Improved ignition accuracy
• More precise fuel delivery
• Enhanced engine response
• Improved idle stability
• Better cold-start performance
• Greater tuning flexibility
• Optimised engine efficiency
• Support for advanced ECU functionality

For high-performance Porsche engine builds, accurate camshaft position monitoring is often essential for extracting maximum performance and drivability.

Why Is an ITB Upgrade So Appealing?

Individual Throttle Body systems are widely regarded as one of the most desirable naturally aspirated performance upgrades available for Porsche engines.

Unlike conventional intake systems, ITBs provide each cylinder with its own dedicated throttle body, dramatically improving airflow characteristics and throttle response.

Benefits of a Rennen by JSR ITB conversion include:

• Instant throttle response
• Improved engine breathing
• Increased airflow efficiency
• Enhanced induction sound
• Greater tuning flexibility
• Improved driver engagement
• Increased performance potential
• Motorsport-inspired engine character

When combined with modern EFI and engine management systems, ITBs deliver a unique driving experience that blends classic Porsche character with modern performance technology.

Why Choose the Rennen by JSR Cam Sensor Bracket?

A precision-engineered sensor mounting solution is critical for accurate ECU operation.

Benefits include:

• Secure sensor mounting
• Accurate sensor positioning
• Improved ECU signal reliability
• Enhanced engine management performance
• Greater tuning accuracy
• Improved engine synchronisation
• Reliable operation in road and motorsport environments
• Professional-quality installation       

Mechanical Throttle Linkage Assembly for Individual Throttle Body (ITB) Systems

The Rennen Mechanical Throttle Linkage Assembly is a precision-engineered solution designed specifically for Rennen Individual Throttle Body (ITB) conversions. Available in two configurations, one for the traditional solid accelerator rod system found in classic Porsche 911 models and another for the accelerator cable system used on Porsche 964 models, this assembly provides smooth, accurate and reliable throttle operation.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

As one of the most critical components in an ITB installation, the throttle linkage transfers driver input directly to the throttle bodies, ensuring precise synchronisation and immediate engine response. Designed to integrate seamlessly with Rennen by JSR ITB systems, the linkage assembly delivers the direct mechanical feel Porsche enthusiasts expect while maintaining excellent throttle control and drivability.

Whether you're building a high-performance road car, a track-focused machine or a fully restored air-cooled Porsche, a properly engineered throttle linkage is essential for unlocking the full potential of an ITB conversion.

What Does a Mechanical Throttle Linkage Do?

The throttle linkage connects the accelerator pedal mechanism to the individual throttle bodies, translating driver input into precise throttle movement.

Its primary functions include:

• Controlling throttle opening and closing
• Synchronising multiple throttle bodies
• Delivering accurate throttle response
• Providing smooth pedal feel
• Maintaining consistent throttle operation
• Supporting reliable engine performance

The assembly is available in two versions:

Porsche 911 Solid Accelerator Rod Version

Designed for classic Porsche 911 models that utilise the factory mechanical rod linkage system. This version integrates with the original accelerator rod arrangement while providing accurate control of the ITB system.

Porsche 964 Accelerator Cable Version

Designed for Porsche 964 models equipped with a throttle cable system. This version provides a clean and reliable connection between the accelerator cable and the individual throttle body assembly.

Why Is an ITB Upgrade So Appealing?

Individual Throttle Body systems are widely considered one of the most rewarding naturally aspirated performance upgrades available for Porsche engines.

Unlike conventional intake systems that use a shared plenum, ITBs provide each cylinder with its own dedicated throttle body, allowing the engine to breathe more efficiently and respond instantly to throttle inputs.

Benefits of a Rennen by JSR ITB conversion include:

• Immediate throttle response
• Improved airflow efficiency
• Enhanced engine breathing
• Increased performance potential
• Greater tuning flexibility
• Distinctive induction sound
• Improved driver engagement
• Motorsport-inspired driving characteristics

For many Porsche enthusiasts, the combination of razor-sharp throttle response and an unmistakable induction note makes ITBs one of the most desirable engine upgrades available.

Why a Quality Throttle Linkage Matters

Even the best throttle bodies cannot perform correctly without a precise and reliable linkage system.

A high-quality linkage assembly helps:

• Deliver accurate throttle control
• Maintain throttle body synchronisation
• Improve pedal feel
• Eliminate unwanted play or movement
• Support consistent engine tuning
• Improve overall drivability
• Maximise ITB performance benefits

A properly engineered linkage transforms the driving experience by creating a direct connection between the driver and the engine.

Drive By Wire Actuator Assembly for Individual Throttle Body (ITB) Systems

The Rennen by JSR Drive By Wire (DBW) Actuator Assembly is a precision-engineered component designed specifically for use with Rennen by JSR Individual Throttle Body (ITB) conversions. This advanced actuator assembly replaces traditional mechanical throttle linkage systems with modern electronic throttle control, delivering precise throttle operation, improved drivability and seamless integration with modern engine management systems.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

As performance engine builds continue to embrace electronic fuel injection and advanced ECU technology, drive-by-wire systems have become increasingly popular due to their ability to provide highly accurate throttle control, programmable throttle mapping and enhanced engine management capabilities.

For Porsche enthusiasts upgrading to a Rennen by JSR ITB system, the DBW actuator assembly provides a professional solution that combines modern control technology with the exhilarating throttle response and induction characteristics of individual throttle bodies.

What Does a Drive By Wire Actuator Assembly Do?

A Drive By Wire actuator electronically controls throttle opening based on driver input from the accelerator pedal rather than using a traditional cable-operated throttle linkage.

The actuator receives commands from the ECU and precisely controls throttle position to optimise engine response and performance.

Key functions include:

• Electronic throttle control
• Precise throttle positioning
• ECU integration
• Programmable throttle mapping
• Improved throttle response
• Enhanced engine management functionality
• Consistent throttle operation

This technology allows greater flexibility in engine calibration while improving overall drivability.

Why Is an ITB Upgrade So Appealing?

Individual Throttle Body systems remain one of the most desirable naturally aspirated performance upgrades available for Porsche engines.

Unlike conventional intake systems, each cylinder receives airflow through its own dedicated throttle body, reducing intake restrictions and dramatically improving responsiveness.

Benefits of a Rennen by JSR ITB upgrade include:

• Instant throttle response
• Improved airflow efficiency
• Enhanced engine breathing
• Increased performance potential
• Greater tuning flexibility
• Improved driver engagement
• Distinctive induction sound
• Motorsport-inspired driving experience

The combination of ITBs and Drive By Wire technology delivers modern engine control while retaining the raw character and responsiveness enthusiasts seek.

Why Install a Drive By Wire Actuator?

Modern electronic throttle control provides significant advantages over traditional cable-operated systems.

Benefits include:

• More accurate throttle control
• Smooth throttle transitions
• Customisable throttle maps
• Improved ECU integration
• Enhanced drivability
• Simplified installation in EFI conversions
• Compatibility with advanced engine management features
• Improved reliability and consistency

For performance builds, a DBW actuator can unlock advanced tuning strategies that are difficult to achieve with conventional throttle linkages.

Rennen Vacuum Manifold for Individual Throttle Body (ITB) Systems

The Rennen Vacuum Manifold is a key component of the Rennen Individual Throttle Body (ITB) Upgrade system, designed to provide a stable and consistent vacuum signal from multiple throttle bodies on high-performance Porsche engines. Engineered specifically for use with Rennen ITB installations, this vacuum manifold simplifies vacuum management while supporting modern engine management systems, fuel pressure regulators, brake servo systems and manifold pressure sensors.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

Individual Throttle Body systems dramatically improve airflow and throttle response by providing each cylinder with its own dedicated throttle plate. However, because each throttle body only generates a small and highly fluctuating vacuum signal, a vacuum manifold is required to collect and balance vacuum from all cylinders into a stable source that can be used by engine management and ancillary systems.

For Porsche enthusiasts seeking improved engine response, sharper acceleration and enhanced induction sound, the Rennen ITB system delivers one of the most desirable upgrades available for naturally aspirated Porsche engines.

What Does a Vacuum Manifold Do?

A vacuum manifold combines vacuum signals from each individual throttle body into a single, stable vacuum source.

This allows critical engine systems to operate correctly, including:

• Engine management systems
• MAP (Manifold Absolute Pressure) sensors
• Fuel pressure regulators
• Brake servo assistance systems
• Idle control systems
• Vacuum-operated accessories

By smoothing the pulsing vacuum signals generated by individual throttle bodies, the manifold improves tuning accuracy and system reliability.

Why Is an ITB Upgrade So Appealing?

Individual Throttle Body systems are widely regarded as one of the most effective naturally aspirated performance upgrades available for Porsche engines.

Unlike a conventional plenum intake system, each cylinder receives air through its own dedicated throttle body, resulting in significantly improved airflow characteristics and immediate throttle response.

Benefits of a Rennen ITB upgrade include:

• Sharper throttle response
• Improved engine breathing
• Increased airflow efficiency
• Enhanced induction sound
• Greater driver engagement
• Improved tuning flexibility
• Increased performance potential
• Motorsport-inspired engine character

For many Porsche enthusiasts, the instant throttle response and distinctive intake sound are among the most rewarding aspects of an ITB conversion.

Why Replacement or Installation Matters

A properly designed vacuum manifold is essential for extracting the full benefits of an ITB conversion.

Without a stable vacuum source, engine management systems may receive inconsistent readings, affecting drivability, idle quality and tuning accuracy.

Benefits include:

• Stable vacuum signal generation
• Improved ECU calibration accuracy
• Better idle characteristics
• Consistent fuel pressure regulation
• Reliable operation of vacuum-assisted systems
• Simplified installation and plumbing
• Enhanced overall engine performance

Features & Benefits

• Designed for Rennen Individual Throttle Body systems
• Combines vacuum signals from multiple throttle bodies
• Provides stable vacuum reference source
• Supports MAP sensor operation
• Suitable for Rennen EFI conversion projects
• Improves engine management performance
• Ideal for performance and motorsport applications
• Precision-engineered for Porsche engine upgrades       

Rennen ITBs for Air-Cooled Porsche 964 - Advanced Roller Barrel Individual Throttle Bodies 

The Rennen ITBs by JSR represent the next generation of individual throttle body technology for air-cooled Porsche 964 engines. Designed and engineered specifically to extract optimal performance from classic Porsche flat-six engines, these innovative roller barrel throttle bodies deliver exceptional airflow, sharper throttle response, and improved engine efficiency compared to conventional butterfly valve throttle body systems.

Fits:

• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

Developed through extensive research, flow simulation analysis and real-world testing, the Rennen ITB system provides a premium induction solution for performance-focused Porsche enthusiasts, restorers, track-day drivers and motorsport applications.

Whether you are building a high-performance Porsche 911 engine or converting a classic air-cooled Porsche to modern EFI, Rennen ITBs by JSR offer a significant advancement in intake technology.

Why Choose Rennen Roller Barrel ITBs?

Unlike traditional individual throttle bodies that utilise a butterfly valve positioned directly in the airflow path, the Rennen ITB system features a precision-engineered tapered roller barrel design.

This innovative approach provides several key advantages:

Unrestricted Airflow

The roller barrel design eliminates the butterfly valve obstruction found in conventional throttle bodies. With no throttle plate disrupting airflow, air moves more efficiently into the engine, improving volumetric efficiency and overall performance.

Increased Air Velocity

Because there is no butterfly valve occupying space within the throttle bore, the throttle body diameter can be optimised to maintain higher air velocity. Higher intake air speed promotes superior cylinder filling and enhanced engine response throughout the rev range.

Superior Fuel Atomisation

At partial throttle openings, airflow passes directly over the fuel injector. This promotes exceptional atomisation of the air-fuel mixture, improving combustion efficiency, drivability and throttle progression.

Instant Throttle Response

The short distance between the roller barrel and the inlet valve creates a highly responsive induction system, delivering immediate engine response and a direct connection between driver input and engine output.

The ITB kit comes with the ITBs mounted on intake manifolds and with fuel rails made for the EV6 injector type. 

Advanced Flow Simulation & Development

Extensive computational fluid dynamics (CFD) analysis and development testing have been carried out to optimise every aspect of the Rennen ITB design.

Flow simulation data demonstrates:

• Direct airflow over the fuel injector during part-throttle operation.
• Significantly reduced turbulence around the injector area compared to traditional butterfly throttle bodies.
• Up to 20% less airflow restriction at full throttle when compared with conventional ITB systems.
• Improved airflow consistency across all cylinders for enhanced engine balance and performance.

The result is a highly efficient induction system capable of supporting both fast road and high-performance motorsport applications.

Premium Motorsport-Grade Construction

Every Rennen ITB by JSR system is manufactured to the highest standards using precision CNC machining and premium materials.

Precision CNC Machined

All components are machined from high-grade 6082-T6 aluminium to ensure exceptional dimensional accuracy and durability.

Perfect Airflow Distribution

Tight manufacturing tolerances ensure evenly distributed airflow across all throttle bodies, promoting balanced cylinder performance and simplified engine tuning.

Easy Synchronisation

The robust design incorporates minimal joints and connections, allowing straightforward throttle synchronisation and reducing the need for ongoing adjustment.

Long-Term Reliability

Throttle barrels are mounted within sealed ball bearings for smooth operation, durability and long service life under demanding conditions.

Premium Sealing Technology

All sealing surfaces utilise Viton O-rings to prevent false air entry and maintain optimal engine performance.

Quality Components Throughout

Only premium bearings, rod ends and stainless-steel fasteners are used throughout the assembly, ensuring reliability and durability in both road and track environments.

Hard Anodised Finish - Available in Gun Metal or Black Finish

All aluminium components receive a hard anodised gunmetal grey finish, providing corrosion resistance and an attractive motorsport inspired appearance.

Specification
Fuel Rails machined for EV6 injector type
3 bolt inlet manifold to cylinder head mounting
50mm velocity stack ID
120mm velocity stack length

The Ultimate Porsche Individual Throttle Body Upgrade

For enthusiasts seeking the ultimate air-cooled Porsche induction system, Rennen ITBs by JSR combine cutting-edge engineering, advanced airflow technology and premium construction quality. The innovative roller barrel design delivers exceptional throttle response, improved airflow efficiency, enhanced fuel atomisation and proven performance gains.

Rennen ITBs for Air-Cooled Porsche 964 - Advanced Roller Barrel Individual Throttle Bodies 

The Rennen ITBs by JSR represent the next generation of individual throttle body technology for air-cooled Porsche 964 engines. Designed and engineered specifically to extract optimal performance from classic Porsche flat-six engines, these innovative roller barrel throttle bodies deliver exceptional airflow, sharper throttle response, and improved engine efficiency compared to conventional butterfly valve throttle body systems.

Fits:

• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

Developed through extensive research, flow simulation analysis and real-world testing, the Rennen ITB system provides a premium induction solution for performance-focused Porsche enthusiasts, restorers, track-day drivers and motorsport applications.

Whether you are building a high-performance Porsche 911 engine or converting a classic air-cooled Porsche to modern EFI, Rennen ITBs by JSR offer a significant advancement in intake technology.

Why Choose Rennen Roller Barrel ITBs?

Unlike traditional individual throttle bodies that utilise a butterfly valve positioned directly in the airflow path, the Rennen ITB system features a precision-engineered tapered roller barrel design.

This innovative approach provides several key advantages:

Unrestricted Airflow

The roller barrel design eliminates the butterfly valve obstruction found in conventional throttle bodies. With no throttle plate disrupting airflow, air moves more efficiently into the engine, improving volumetric efficiency and overall performance.

Increased Air Velocity

Because there is no butterfly valve occupying space within the throttle bore, the throttle body diameter can be optimised to maintain higher air velocity. Higher intake air speed promotes superior cylinder filling and enhanced engine response throughout the rev range.

Superior Fuel Atomisation

At partial throttle openings, airflow passes directly over the fuel injector. This promotes exceptional atomisation of the air-fuel mixture, improving combustion efficiency, drivability and throttle progression.

Instant Throttle Response

The short distance between the roller barrel and the inlet valve creates a highly responsive induction system, delivering immediate engine response and a direct connection between driver input and engine output.

The ITB kit comes with the ITBs mounted on intake manifolds and with fuel rails made for the EV6 injector type. 

Advanced Flow Simulation & Development

Extensive computational fluid dynamics (CFD) analysis and development testing have been carried out to optimise every aspect of the Rennen ITB design.

Flow simulation data demonstrates:

• Direct airflow over the fuel injector during part-throttle operation.
• Significantly reduced turbulence around the injector area compared to traditional butterfly throttle bodies.
• Up to 20% less airflow restriction at full throttle when compared with conventional ITB systems.
• Improved airflow consistency across all cylinders for enhanced engine balance and performance.

The result is a highly efficient induction system capable of supporting both fast road and high-performance motorsport applications.

Premium Motorsport-Grade Construction

Every Rennen ITB by JSR system is manufactured to the highest standards using precision CNC machining and premium materials.

Precision CNC Machined

All components are machined from high-grade 6082-T6 aluminium to ensure exceptional dimensional accuracy and durability.

Perfect Airflow Distribution

Tight manufacturing tolerances ensure evenly distributed airflow across all throttle bodies, promoting balanced cylinder performance and simplified engine tuning.

Easy Synchronisation

The robust design incorporates minimal joints and connections, allowing straightforward throttle synchronisation and reducing the need for ongoing adjustment.

Long-Term Reliability

Throttle barrels are mounted within sealed ball bearings for smooth operation, durability and long service life under demanding conditions.

Premium Sealing Technology

All sealing surfaces utilise Viton O-rings to prevent false air entry and maintain optimal engine performance.

Quality Components Throughout

Only premium bearings, rod ends and stainless-steel fasteners are used throughout the assembly, ensuring reliability and durability in both road and track environments.

Hard Anodised Finish - Available in Gun Metal or Black Finish

All aluminium components receive a hard anodised gunmetal grey finish, providing corrosion resistance and an attractive motorsport inspired appearance.

Specification
Fuel Rails machined for EV6 injector type
3 bolt inlet manifold to cylinder head mounting
48mm velocity stack ID
120mm velocity stack length

The Ultimate Porsche Individual Throttle Body Upgrade

For enthusiasts seeking the ultimate air-cooled Porsche induction system, Rennen ITBs by JSR combine cutting-edge engineering, advanced airflow technology and premium construction quality. The innovative roller barrel design delivers exceptional throttle response, improved airflow efficiency, enhanced fuel atomisation and proven performance gains.

Rennen ITBs for Air-Cooled Porsche 911 - Advanced Roller Barrel Individual Throttle Bodies 

The Rennen ITBs by JSR represent the next generation of individual throttle body technology for air-cooled Porsche 911 engines. Designed and engineered specifically to extract optimal performance from classic Porsche flat-six engines, these innovative roller barrel throttle bodies deliver exceptional airflow, sharper throttle response, and improved engine efficiency compared to conventional butterfly valve throttle body systems.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50

Developed through extensive research, flow simulation analysis and real-world testing, the Rennen ITB system provides a premium induction solution for performance-focused Porsche enthusiasts, restorers, track-day drivers and motorsport applications.

Whether you are building a high-performance Porsche 911 engine or converting a classic air-cooled Porsche to modern EFI, Rennen ITBs by JSR offer a significant advancement in intake technology.

Why Choose Rennen Roller Barrel ITBs?

Unlike traditional individual throttle bodies that utilise a butterfly valve positioned directly in the airflow path, the Rennen ITB system features a precision-engineered tapered roller barrel design.

This innovative approach provides several key advantages:

Unrestricted Airflow

The roller barrel design eliminates the butterfly valve obstruction found in conventional throttle bodies. With no throttle plate disrupting airflow, air moves more efficiently into the engine, improving volumetric efficiency and overall performance.

Increased Air Velocity

Because there is no butterfly valve occupying space within the throttle bore, the throttle body diameter can be optimised to maintain higher air velocity. Higher intake air speed promotes superior cylinder filling and enhanced engine response throughout the rev range.

Superior Fuel Atomisation

At partial throttle openings, airflow passes directly over the fuel injector. This promotes exceptional atomisation of the air-fuel mixture, improving combustion efficiency, drivability and throttle progression.

Instant Throttle Response

The short distance between the roller barrel and the inlet valve creates a highly responsive induction system, delivering immediate engine response and a direct connection between driver input and engine output.

 The ITB kit comes with the ITBs mounted on intake manifolds and with fuel rails made for the EV6 injector type. 

Advanced Flow Simulation & Development

Extensive computational fluid dynamics (CFD) analysis and development testing have been carried out to optimise every aspect of the Rennen ITB design.

Flow simulation data demonstrates:

• Direct airflow over the fuel injector during part-throttle operation.
• Significantly reduced turbulence around the injector area compared to traditional butterfly throttle bodies.
• Up to 20% less airflow restriction at full throttle when compared with conventional ITB systems.
• Improved airflow consistency across all cylinders for enhanced engine balance and performance.

The result is a highly efficient induction system capable of supporting both fast road and high-performance motorsport applications.

Premium Motorsport-Grade Construction

Every Rennen ITB by JSR system is manufactured to the highest standards using precision CNC machining and premium materials.

Precision CNC Machined

All components are machined from high-grade 6082-T6 aluminium to ensure exceptional dimensional accuracy and durability.

Perfect Airflow Distribution

Tight manufacturing tolerances ensure evenly distributed airflow across all throttle bodies, promoting balanced cylinder performance and simplified engine tuning.

Easy Synchronisation

The robust design incorporates minimal joints and connections, allowing straightforward throttle synchronisation and reducing the need for ongoing adjustment.

Long-Term Reliability

Throttle barrels are mounted within sealed ball bearings for smooth operation, durability and long service life under demanding conditions.

Premium Sealing Technology

All sealing surfaces utilise Viton O-rings to prevent false air entry and maintain optimal engine performance.

Quality Components Throughout

Only premium bearings, rod ends and stainless-steel fasteners are used throughout the assembly, ensuring reliability and durability in both road and track environments.

Hard Anodised Finish - Available in Gun Metal or Black Finish

All aluminium components receive a hard anodised gunmetal grey finish, providing corrosion resistance and an attractive motorsport inspired appearance.

Specification
Fuel Rails machined for EV6 injector type
2 bolt inlet manifold to cylinder head mounting
48mm velocity stack ID
120mm velocity stack length

The Ultimate Porsche Individual Throttle Body Upgrade

For enthusiasts seeking the ultimate air-cooled Porsche induction system, Rennen ITBs by JSR combine cutting-edge engineering, advanced airflow technology and premium construction quality. The innovative roller barrel design delivers exceptional throttle response, improved airflow efficiency, enhanced fuel atomisation and proven performance gains.

Rennen ITB Black Velocity Stacks for Air-Cooled Porsche 911 - Set of 6

Precision-Engineered Velocity Stacks Designed Exclusively for Rennen ITBs

Rennen ITB Velocity Stacks have been specifically developed for use with the innovative Rennen ITB by JSR roller barrel throttle body system. Designed to maximise airflow efficiency and complement the advanced induction characteristics of the Rennen ITB, these premium velocity stacks help optimise engine breathing, improve airflow stability and support maximum performance from your air-cooled Porsche 911 engine.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

Manufactured to exacting standards and available in both silver and black finishes, these velocity stacks provide the perfect finishing touch for high-performance Porsche engine builds, restomods, track cars and motorsport applications.

Available Sizes and Engine Size Combinations

Each velocity stack features an overall length of 120mm and is available in three internal diameter options to suit a variety of engine specifications and performance requirements:

• 2.7ltr / 3.0ltr Engine - 45mm Internal Diameter (ID)
• 3.2ltr / 3.5ltr / 3.6ltr Engine - 48mm Internal Diameter (ID)
• 4.0ltr Engine - 50mm Internal Diameter (ID)

These sizing options allow engine builders and tuners to select the most suitable intake configuration based on engine displacement, camshaft profile, intended RPM range and performance objectives.

Optimised Airflow Performance

The carefully designed bellmouth entry profile promotes smooth airflow into the throttle body, helping reduce turbulence and improve air velocity. This allows the induction system to operate more efficiently throughout the rev range while maintaining the sharp throttle response that the Rennen ITB system is renowned for.

By creating a smoother transition for incoming air, Rennen Velocity Stacks contribute to improved cylinder filling and consistent airflow delivery across all cylinders.

Premium Construction

Designed to match the quality and engineering standards of the Rennen ITB system, these velocity stacks offer exceptional durability and an outstanding motorsport-inspired appearance.

Key Features

• Designed exclusively for Rennen ITBs by JSR
• Available in silver or black finish 120mm overall length
• Available in 45mm, 48mm and 50mm internal diameters
• Precision-machined construction
• Optimised bellmouth profile for improved airflow
• Supports enhanced induction efficiency
• Complements Rennen roller barrel throttle body systems
• Suitable for road, track and race applications
• Designed for air-cooled Porsche 911 performance engines

The Perfect Addition to Your Rennen ITB Installation

Whether you are building a fast-road Porsche 911, a high-performance restomod, or a dedicated motorsport engine, Rennen ITB Velocity Stacks provide the ideal airflow solution for your induction system. Designed specifically to work with the Rennen roller barrel throttle bodies, they help deliver the performance, drivability and appearance expected from a premium Porsche performance upgrade.

Rennen ITB Silver Velocity Stacks for Air-Cooled Porsche 911 - Set of 6

Precision-Engineered Velocity Stacks Designed Exclusively for Rennen ITBs

Rennen ITB Velocity Stacks have been specifically developed for use with the innovative Rennen ITB by JSR roller barrel throttle body system. Designed to maximise airflow efficiency and complement the advanced induction characteristics of the Rennen ITB, these premium velocity stacks help optimise engine breathing, improve airflow stability and support maximum performance from your air-cooled Porsche 911 engine.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC
• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• Porsche 964 (911) C2 1989-93
• Porsche 964 (911) C4 1989-93
• Porsche 964 (911) RS 3.6L 1991-93
• Porsche 964 (911) RS 3.8L 1991-93

Manufactured to exacting standards and available in both silver and black finishes, these velocity stacks provide the perfect finishing touch for high-performance Porsche engine builds, restomods, track cars and motorsport applications.

Available Sizes and Engine Size Combinations

Each velocity stack features an overall length of 120mm and is available in three internal diameter options to suit a variety of engine specifications and performance requirements:

• 2.7ltr / 3.0ltr Engine - 45mm Internal Diameter (ID)
• 3.2ltr / 3.5ltr / 3.6ltr Engine - 48mm Internal Diameter (ID)
• 4.0ltr Engine - 50mm Internal Diameter (ID)

These sizing options allow engine builders and tuners to select the most suitable intake configuration based on engine displacement, camshaft profile, intended RPM range and performance objectives.

Optimised Airflow Performance

The carefully designed bellmouth entry profile promotes smooth airflow into the throttle body, helping reduce turbulence and improve air velocity. This allows the induction system to operate more efficiently throughout the rev range while maintaining the sharp throttle response that the Rennen ITB system is renowned for.

By creating a smoother transition for incoming air, Rennen Velocity Stacks contribute to improved cylinder filling and consistent airflow delivery across all cylinders.

Premium Construction

Designed to match the quality and engineering standards of the Rennen ITB system, these velocity stacks offer exceptional durability and an outstanding motorsport-inspired appearance.

Key Features

• Designed exclusively for Rennen ITBs by JSR
• Available in silver or black finish 120mm overall length
• Available in 45mm, 48mm and 50mm internal diameters
• Precision-machined construction
• Optimised bellmouth profile for improved airflow
• Supports enhanced induction efficiency
• Complements Rennen roller barrel throttle body systems
• Suitable for road, track and race applications
• Designed for air-cooled Porsche 911 performance engines

The Perfect Addition to Your Rennen ITB Installation

Whether you are building a fast-road Porsche 911, a high-performance restomod, or a dedicated motorsport engine, Rennen ITB Velocity Stacks provide the ideal airflow solution for your induction system. Designed specifically to work with the Rennen roller barrel throttle bodies, they help deliver the performance, drivability and appearance expected from a premium Porsche performance upgrade.

Rennen ITBs for Air-Cooled Porsche 911 - Advanced Roller Barrel Individual Throttle Bodies 

The Rennen ITBs by JSR represent the next generation of individual throttle body technology for air-cooled Porsche 911 engines. Designed and engineered specifically to extract optimal performance from classic Porsche flat-six engines, these innovative roller barrel throttle bodies deliver exceptional airflow, sharper throttle response, and improved engine efficiency compared to conventional butterfly valve throttle body systems.

Fits:

• Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC

Developed through extensive research, flow simulation analysis and real-world testing, the Rennen ITB system provides a premium induction solution for performance-focused Porsche enthusiasts, restorers, track-day drivers and motorsport applications.

Whether you are building a high-performance Porsche 911 engine or converting a classic air-cooled Porsche to modern EFI, Rennen ITBs by JSR offer a significant advancement in intake technology.

Why Choose Rennen Roller Barrel ITBs?

Unlike traditional individual throttle bodies that utilise a butterfly valve positioned directly in the airflow path, the Rennen ITB system features a precision-engineered tapered roller barrel design.

This innovative approach provides several key advantages:

Unrestricted Airflow

The roller barrel design eliminates the butterfly valve obstruction found in conventional throttle bodies. With no throttle plate disrupting airflow, air moves more efficiently into the engine, improving volumetric efficiency and overall performance.

Increased Air Velocity

Because there is no butterfly valve occupying space within the throttle bore, the throttle body diameter can be optimised to maintain higher air velocity. Higher intake air speed promotes superior cylinder filling and enhanced engine response throughout the rev range.

Superior Fuel Atomisation

At partial throttle openings, airflow passes directly over the fuel injector. This promotes exceptional atomisation of the air-fuel mixture, improving combustion efficiency, drivability and throttle progression.

Instant Throttle Response

The short distance between the roller barrel and the inlet valve creates a highly responsive induction system, delivering immediate engine response and a direct connection between driver input and engine output.

 The ITB kit comes with the ITBs mounted on intake manifolds and with fuel rails made for the EV6 injector type.

Advanced Flow Simulation & Development

Extensive computational fluid dynamics (CFD) analysis and development testing have been carried out to optimise every aspect of the Rennen ITB design.

Flow simulation data demonstrates:

• Direct airflow over the fuel injector during part-throttle operation.
• Significantly reduced turbulence around the injector area compared to traditional butterfly throttle bodies.
• Up to 20% less airflow restriction at full throttle when compared with conventional ITB systems.
• Improved airflow consistency across all cylinders for enhanced engine balance and performance.

The result is a highly efficient induction system capable of supporting both fast road and high-performance motorsport applications.

Premium Motorsport-Grade Construction

Every Rennen ITB by JSR system is manufactured to the highest standards using precision CNC machining and premium materials.

Precision CNC Machined

All components are machined from high-grade 6082-T6 aluminium to ensure exceptional dimensional accuracy and durability.

Perfect Airflow Distribution

Tight manufacturing tolerances ensure evenly distributed airflow across all throttle bodies, promoting balanced cylinder performance and simplified engine tuning.

Easy Synchronisation

The robust design incorporates minimal joints and connections, allowing straightforward throttle synchronisation and reducing the need for ongoing adjustment.

Long-Term Reliability

Throttle barrels are mounted within sealed ball bearings for smooth operation, durability and long service life under demanding conditions.

Premium Sealing Technology

All sealing surfaces utilise Viton O-rings to prevent false air entry and maintain optimal engine performance.

Quality Components Throughout

Only premium bearings, rod ends and stainless-steel fasteners are used throughout the assembly, ensuring reliability and durability in both road and track environments.

Hard Anodised Finish - Available in Gun Metal or Black Finish

All aluminium components receive a hard anodised gunmetal grey finish, providing corrosion resistance and an attractive motorsport inspired appearance.

Specification
Fuel Rails machined for EV6 injector type
2 bolt inlet manifold to cylinder head mounting
45mm velocity stack ID
120mm velocity stack length

The Ultimate Porsche Individual Throttle Body Upgrade

For enthusiasts seeking the ultimate air-cooled Porsche induction system, Rennen ITBs by JSR combine cutting-edge engineering, advanced airflow technology and premium construction quality. The innovative roller barrel design delivers exceptional throttle response, improved airflow efficiency, enhanced fuel atomisation and proven performance gains.