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Electronic Fuel Injection Throttle Kits
- 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
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
- 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
Rennen ITG Plenum Flange Set for Rennen by JSR Individual Barrel Throttle Body Upgrades
The Rennen ITG Plenum Flange Set is a precision-engineered conversion solution designed specifically for Rennen by JSR Individual Barrel Throttle Body (ITB) systems. These bespoke flanges attach directly to the top of the Rennen Barrel Throttle Bodies and provide a secure mounting platform for an intake plenum chamber, replacing the traditional velocity stack arrangement.
Fits:
- 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
Plenum Inlet Diameter Options:
48mm
– suitable for Porsche 3.2ltr, 3.5ltr and 3.6ltr engines
50mm – suitable for Porsche 4.0ltr engines.
Please note:
Plenum adaptor flanges are not available for
2.7 or 3.0ltr engine applications.
Supplied complete with the required mounting and securing hardware, the flange set allows engine builders and tuners to configure their induction system for plenum operation while retaining all the airflow benefits of the Rennen Barrel ITB architecture. Please note that the plenum chamber itself is not included.
This system is ideal for builders seeking alternative intake packaging solutions, improved intake air management, advanced engine management strategies or custom naturally aspirated and forced induction applications.
What Does the ITG Plenum Flange Set Do?
The flange set creates a mounting interface between the Barrel Throttle Bodies and a plenum chamber.
Its primary functions include:
- Providing secure plenum mounting
- Replacing traditional velocity stacks
- Creating a sealed induction system
- Supporting custom intake configurations
- Improving intake packaging options
- Allowing integration with plenum-based induction systems
- Supporting advanced engine management strategies
The flanges form the critical connection point between the throttle bodies and the plenum assembly.
Why Use a Plenum Instead of Velocity Stacks?
Velocity stacks are ideal for maximising throttle response and creating the classic ITB appearance. However, some applications benefit from using a plenum chamber.
Advantages of plenum systems include:
- Controlled intake air supply
- Improved intake packaging flexibility
- Easier integration with air filter systems
- Reduced intake noise
- Consistent air distribution
- Improved airflow management
- Greater flexibility for custom engine builds
The choice between velocity stacks and a plenum depends on the engine's intended use and performance objectives.
Why Is the Plenum Flange Set Important?
Without the correct mounting solution, a plenum cannot be securely attached to the throttle body assembly.
The Rennen ITG Plenum Flange Set provides:
- Correct fitment to Rennen Barrel ITBs
- Reliable sealing surfaces
- Secure plenum attachment points
- Professional installation quality
- Simplified custom intake fabrication
- Compatibility with bespoke induction systems
- Long-term durability
The flange set is the foundation of any successful plenum-based ITB installation.
Why Are Barrel ITB Upgrades So Popular?
Rennen by JSR Barrel Throttle Bodies are designed to maximise airflow and engine responsiveness while offering exceptional tuning flexibility.
Benefits include:
- Instant throttle response
- Increased airflow efficiency
- Enhanced engine breathing
- Greater power potential
- Improved torque characteristics
- Exceptional tuning capability
- Motorsport-inspired engineering
- Stunning engine bay presentation
The Plenum Flange Set expands these possibilities by allowing the induction system to be tailored to the specific requirements of the engine build.
Why Choose the Rennen ITG Plenum Flange Set?
Developed specifically for Rennen by JSR ITB systems, these flanges offer a professional and reliable solution for plenum-based induction conversions.
Benefits include:
- Precision-engineered fitment
- Direct compatibility with Rennen Barrel ITBs
- Complete mounting hardware included
- Supports custom plenum installations
- Professional installation solution
- Durable construction
- Suitable for road and motorsport applications
- 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
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.
Upgrade your Porsche 911 with one of the most advanced individual throttle body systems available and experience a new level of engine responsiveness, drivability and performance
- 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
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.
Upgrade your Porsche 911 with one of the most advanced individual throttle body systems available and experience a new level of engine responsiveness, drivability and performance
- 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 Bodies (ITB) Upgrade with ITG Normal Air Filter Set
Transform the character, responsiveness and visual appeal of your air-cooled Porsche with the Rennen by JSR Individual Roller Barrel Throttle Bodies (ITB) Upgrade for the Porsche 964 3.6ltr engine. Finished in a striking gunmetal coating and supplied with silver velocity stacks, ITG foam 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
- ITG filters - Rennen normal version
- 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.
- 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 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.
- 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
Rennen by JSR Individual Throttle Bodies (ITB) Upgrade for Modified Porsche 964 4.0ltr Engine
Developed for serious air-cooled Porsche performance builds,
the Rennen by JSR Individual Throttle Bodies (ITB) Upgrade Kit for the Porsche
964 4.0ltr engine delivers exceptional airflow, lightning-fast throttle
response and a true motorsport-inspired driving experience. Specifically
configured for modified 4.0ltr engines featuring 45mm inlet bores and 50mm
internal diameter Velocity Stacks, this induction package has been engineered
to support the increased airflow demands of high-output naturally aspirated
engine builds.
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
This premium specification combines Gun Metal Individual Throttle Bodies, 50mm Silver Velocity Stacks, the Rennen Classic Mesh and Foam Air Filter Set and a Mechanical Throttle Linkage System, creating one of the most capable and visually impressive induction systems available for the Porsche 964 platform.
Whether fitted to a fast-road build, high-end restomod, track-focused machine or bespoke engine project, this system transforms the character of the Porsche flat-six while maximising its performance potential.
Designed for Modified 4.0ltr Engines
This ITB system has been developed specifically for enlarged-capacity Porsche 964 engines built to 4.0ltr and featuring 45mm inlet bores.
The larger bore specification provides:
- Increased airflow capacity
- Improved cylinder filling
- Enhanced high-RPM breathing
- Greater power potential
- Improved volumetric efficiency
- Enhanced throttle response
- Optimised compatibility with performance cylinder heads and camshafts
Combined with the 50mm velocity stack configuration, the system supports the airflow requirements of serious performance engine builds.
Why Upgrade to Individual Throttle Bodies?
Unlike a conventional plenum intake system, Individual Throttle Bodies provide each cylinder with its own dedicated throttle opening.
Benefits include:
- Instant throttle response
- Reduced intake restriction
- Improved airflow distribution
- Enhanced engine breathing
- Sharper acceleration
- Increased power potential
- Greater tuning flexibility
- Motorsport-inspired driving experience
The result is an engine that feels more responsive, more aggressive and more connected to driver inputs throughout the rev range.
Gun Metal Throttle Bodies
The Gun Metal finish provides a sophisticated motorsport appearance while showcasing the engineering quality of the induction system.
Benefits include:
- Premium finish
- Durable construction
- Distinctive engine bay appearance
- Complements air-cooled
- Porsche aesthetics
- Motorsport-inspired styling
50mm Silver Velocity Stacks
The oversized 50mm Velocity Stacks are specifically selected to complement the airflow requirements of the modified 4.0ltr engine.
Benefits include:
- Increased airflow capacity
- Reduced intake restriction
- Enhanced cylinder filling
- Improved throttle response
- Optimised high-performance breathing
- Classic Porsche race-engine appearance
These larger stacks are ideally suited to engines built for maximum naturally aspirated performance.
Classic
Mesh & Foam Air Filters
This package includes the Rennen ITG Classic Mesh & Foam Air Filter
Set, designed specifically to fit directly onto the 50mm Velocity Stacks.
Benefits include:
The exposed mesh design perfectly complements the period-inspired appearance of the air-cooled flat-six while providing essential engine protection.
Mechanical Throttle Linkage
This kit includes the traditional mechanical throttle linkage system preferred by many Porsche enthusiasts.
Benefits include:
- Direct throttle feel
- Immediate driver feedback
- Proven reliability
- Authentic air-cooled character
- Motorsport-style operation
The mechanical linkage enhances the tactile and engaging nature of the ITB driving experience.
Why Choose the Rennen by JSR ITB System?
The Rennen by JSR system has been developed specifically for Porsche performance applications and engineered to maximise the potential of naturally aspirated air-cooled engines.
Benefits include:
- Exceptional throttle response
- Increased airflow capacity
- Improved engine breathing
- Enhanced induction acoustics
- Greater power potential
- Porsche-specific engineering
- Premium component quality
- Stunning engine bay presentation
It represents one of the most desirable induction upgrades available for a modified Porsche 964.
- 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
Rennen by JSR Individual Throttle Bodies (ITB) Upgrade for Modified Porsche 964 4.0ltr Engine
Developed for serious air-cooled Porsche performance builds,
the Rennen by JSR Individual Throttle Bodies (ITB) Upgrade Kit for the Porsche
964 4.0ltr engine delivers exceptional airflow, lightning-fast throttle
response and a true motorsport-inspired driving experience. Specifically
configured for modified 4.0ltr engines featuring 45mm inlet bores and 50mm
internal diameter Velocity Stacks, this induction package has been engineered
to support the increased airflow demands of high-output naturally aspirated
engine builds.
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
This premium specification combines Gun Metal Individual Throttle Bodies, 50mm Silver Velocity Stacks, the Rennen ITG Air Filter Assembly (Normal Specification) and a Mechanical Throttle Linkage System, creating one of the most capable and visually impressive induction systems available for the Porsche 964 platform.
Whether fitted to a fast-road build, high-end restomod, track-focused machine or bespoke engine project, this system transforms the character of the Porsche flat-six while maximising its performance potential.
Designed for Modified 4.0ltr Engines
This ITB system has been developed specifically for enlarged-capacity Porsche 964 engines built to 4.0ltr and featuring 45mm inlet bores.
The larger bore specification provides:
- Increased airflow capacity
- Improved cylinder filling
- Enhanced high-RPM breathing
- Greater power potential
- Improved volumetric efficiency
- Enhanced throttle response
- Optimised compatibility with performance cylinder heads and camshafts
Combined with the 50mm velocity stack configuration, the system supports the airflow requirements of serious performance engine builds.
Why Upgrade to Individual Throttle Bodies?
Unlike a conventional plenum intake system, Individual Throttle Bodies provide each cylinder with its own dedicated throttle opening.
Benefits include:
- Instant throttle response
- Reduced intake restriction
- Improved airflow distribution
- Enhanced engine breathing
- Sharper acceleration
- Increased power potential
- Greater tuning flexibility
- Motorsport-inspired driving experience
The result is an engine that feels more responsive, more aggressive and more connected to driver inputs throughout the rev range.
Gun Metal Throttle Bodies
The Gun Metal finish provides a sophisticated motorsport appearance while showcasing the engineering quality of the induction system.
Benefits include:
- Premium finish
- Durable construction
- Distinctive engine bay appearance
- Complements air-cooled
- Porsche aesthetics
- Motorsport-inspired styling
50mm Silver Velocity Stacks
The oversized 50mm Velocity Stacks are specifically selected to complement the airflow requirements of the modified 4.0ltr engine.
Benefits include:
- Increased airflow capacity
- Reduced intake restriction
- Enhanced cylinder filling
- Improved throttle response
- Optimised high-performance breathing
- Classic Porsche race-engine appearance
These larger stacks are ideally suited to engines built for maximum naturally aspirated performance.
ITG Air Filter Assembly (Normal Specification)
The included ITG Air Filter Assembly provides effective filtration without compromising airflow.
Benefits include:
- Protects engine internals
- Maintains high airflow efficiency
- Washable and reusable filter media
- Supports engine longevity
- Suitable for road and fast-road applications
The normal specification assembly provides an ideal balance between filtration, airflow and practicality.
Mechanical Throttle Linkage
This kit includes the traditional mechanical throttle linkage system preferred by many Porsche enthusiasts.
Benefits include:
- Direct throttle feel
- Immediate driver feedback
- Proven reliability
- Authentic air-cooled character
- Motorsport-style operation
The mechanical linkage enhances the tactile and engaging nature of the ITB driving experience.
Why Choose the Rennen by JSR ITB System?
The Rennen by JSR system has been developed specifically for Porsche performance applications and engineered to maximise the potential of naturally aspirated air-cooled engines.
Benefits include:
- Exceptional throttle response
- Increased airflow capacity
- Improved engine breathing
- Enhanced induction acoustics
- Greater power potential
- Porsche-specific engineering
- Premium component quality
- Stunning engine bay presentation
It represents one of the most desirable induction upgrades available for a modified Porsche 964.
- 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
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.
- 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
Rennen Throttle Position Sensor (TPS) for Rennen by JSR Individual Barrel Throttle Body Upgrades
The Rennen Throttle Position Sensor (TPS) is a critical engine management component designed specifically for use with Rennen by JSR Individual Barrel Throttle Body (ITB) upgrades. Mounted directly to the throttle assembly, the TPS continuously measures throttle opening angle and relays this information to the engine control unit (ECU), allowing precise fuel and ignition calculations throughout the engine's operating range.
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
When upgrading a Porsche engine to Individual Barrel Throttle Bodies, accurate throttle position data becomes even more important. The instantaneous airflow characteristics of ITBs demand rapid ECU response, and the TPS provides the critical information required to deliver smooth drivability, sharp throttle response and maximum performance.
Whether you're building a fast road Porsche, a track day machine or a dedicated motorsport engine, the TPS is an essential component in achieving a professional and properly calibrated ITB installation.
What Does a Throttle Position Sensor Do?
The Throttle Position Sensor measures the exact position of the throttle barrels and communicates this information directly to the ECU.
The ECU uses this data to determine:
- Throttle opening percentage
- Driver demand
- Acceleration enrichment requirements
- Ignition timing adjustments
- Fuel delivery calculations
- Deceleration fuel cut strategies
- Idle and part-throttle control
A properly functioning TPS helps provide:
- Instant throttle response
- Accurate fuel mapping
- Smooth acceleration
- Stable idle quality
- Improved drivability
- Enhanced engine performance
- Reliable ECU operation
Without accurate throttle position data, modern engine management systems cannot react correctly to driver inputs.
Why Is a TPS Essential for ITB Conversions?
Individual Barrel Throttle Bodies dramatically improve airflow and engine response, but they also require more precise engine management control.
Unlike traditional airflow-restricted intake systems, ITBs allow airflow to increase almost instantly as the throttle opens. The ECU therefore relies heavily on TPS input to determine fuel and ignition requirements during rapid throttle movements.
The TPS allows:
- Accurate throttle-based load calculations
- Faster ECU response times
- Improved transient fueling
- Smoother acceleration
- Better throttle modulation
- Enhanced drivability
- More accurate engine calibration
Without a TPS, an ITB-equipped engine can suffer from hesitation, poor throttle transitions and inconsistent performance.
Why Are Barrel ITB Upgrades So Popular?
Rennen by JSR Barrel Throttle Bodies are engineered to maximise airflow while delivering a true motorsport-inspired driving experience.
Benefits include:
- Instant throttle response
- Increased airflow efficiency
- Improved engine breathing
- Enhanced power potential
- Greater tuning flexibility
- Exceptional induction sound
- Improved driver engagement
- Stunning engine bay appearance
When combined with a correctly calibrated ECU, MAP sensor and TPS, the result is an engine that delivers exceptional responsiveness and performance.
Why Choose the Rennen TPS?
Developed specifically for Rennen by JSR ITB applications, this sensor delivers the accuracy and reliability required for professional-level ECU calibration and performance tuning.
Benefits include:
- Accurate throttle position measurement
- Compatible with Rennen by JSR Barrel ITBs
- Supports standalone ECU systems
- Improves tuning precision
- Enhances throttle response
- Supports motorsport and fast road applications
- Reliable long-term performance
- Essential for modern EFI engine management
- 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
Rennen Vacuum Fittings & Tube Set for Use with Rennen Vacuum Manifold
Complete your Porsche Barrel Individual Throttle Body conversion with the Rennen Vacuum Fittings & Tube Set, specifically engineered for use with the Rennen by JSR Vacuum Manifold. This installation kit provides the vacuum fittings, connectors and tubing required to correctly link each throttle body to the vacuum manifold, ensuring a stable and reliable vacuum signal for engine management and ancillary 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
Designed exclusively for Rennen by JSR Barrel ITB systems, this kit forms an essential part of the overall induction and engine management package. By combining the vacuum signals from each individual throttle body, the system creates a stable vacuum source that can be used for MAP sensors, fuel pressure regulators, idle control strategies and other engine management functions.
For any EFI-controlled Individual Throttle Body conversion, achieving a consistent vacuum signal is critical to drivability, tuning accuracy and overall engine performance.
What Does the Vacuum Fittings & Tube Set Do?
Individual throttle body systems generate vacuum independently from each intake runner. Because these vacuum signals fluctuate rapidly, they need to be combined through a vacuum manifold system to create a smooth and usable signal.
The Rennen Vacuum Fittings & Tube Set allows:
- Connection of each throttle body to the vacuum manifold
- Stable vacuum signal generation
- Accurate MAP sensor readings
- Improved ECU tuning capability
- Consistent engine load measurement
- Reliable idle control strategies
- Enhanced drivability
Without the correct vacuum plumbing, modern engine management systems can struggle to interpret engine load accurately.
Why Is a Vacuum Manifold Important on Barrel ITBs?
Barrel throttle bodies provide exceptional airflow and throttle response but naturally produce highly pulsed vacuum signals.
The Rennen by JSR Vacuum Manifold and associated fittings
help:
- Smooth vacuum fluctuations
- Improve MAP sensor accuracy
- Enhance fuel delivery calculations
- Improve ignition mapping accuracy
- Stabilise idle operation
- Improve low-speed drivability
- Simplify ECU calibration
The result is a more refined and predictable engine that retains all the performance benefits of an Individual Throttle Body conversion.
Why Are Individual Throttle Body Upgrades So Popular?
Individual Throttle Body systems are widely regarded as one of the most desirable naturally aspirated performance upgrades available for Porsche engines.
Benefits include:
- Instant throttle response
- Improved airflow efficiency
- Enhanced engine breathing
- Increased performance potential
- Greater tuning flexibility
- Motorsport-inspired induction sound
- Improved driver engagement
- Stunning engine bay appearance
When combined with modern EFI systems and correctly configured vacuum management, ITBs deliver exceptional performance and drivability.
Why Choose the Rennen Vacuum Fittings & Tube Set?
This kit has been developed specifically to work with the Rennen by JSR Vacuum Manifold and Barrel ITB systems.
Benefits include:
- Correct fitment for Rennen systems
- Simplified installation
- Reliable vacuum connections
- Improved tuning accuracy
- Stable engine management signals
- Professional conversion finish
- Suitable for road and motorsport use
- Supports advanced ECU functionality
- 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
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
- 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
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.
- 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
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.
Porsche Electronic Fuel Injection Throttle Kits - Precision Airflow & Throttle Control
Electronic Fuel Injection (EFI) Throttle Kits upgrade the engine’s air delivery system, providing precise throttle control, improved airflow, and enhanced engine response. Designed for performance builds, engine conversions, and modernised classic Porsche applications, these kits replace restrictive or outdated throttle systems with advanced electronic throttle bodies and control hardware.
Available from Design911, Porsche EFI throttle kits are engineered to deliver smoother power delivery, sharper throttle response, and improved drivability—especially in tuned, high-performance, or track-focused engines.
What Do Electronic Fuel Injection Throttle Kits Do?
EFI throttle kits regulate the volume of air entering the engine with high precision, directly influencing power and response.
Core Functions:
- Control engine airflow electronically and accurately.
- Improve throttle response and drivability.
- Support higher airflow demands in tuned engines.
- Enable precise fuel and ignition mapping.
- Enhance overall engine efficiency and performance.
Accurate throttle control is essential for modern performance engine management.
Why Do Standard Throttle Systems Fail?
Factory or older throttle systems can become limiting or
unreliable over time, particularly in modified engines. Common issues include:
- Mechanical throttle wear or cable stretch.
- Inconsistent airflow from ageing throttle bodies.
- Restrictive designs limiting high-RPM performance.
- Poor compatibility with modern ECU tuning.
- Inadequate response for high-performance applications.
These limitations can result in sluggish response, uneven power delivery, and reduced tuning potential.
Why Upgrade to an EFI Throttle Kit?
EFI throttle kits are designed to support modern engine management and higher performance demands.
Upgrade Benefits:
- Sharper, more consistent throttle response.
- Increased airflow capacity for power upgrades.
- Improved compatibility with aftermarket ECUs.
- Enhanced drivability for road and track use.
- Ideal for engine builds, conversions, and restorations.
Upgrading to an EFI throttle kit unlocks precise control and maximises engine tuning potential.
Highlights
- Porsche electronic fuel injection throttle kits
- Precision airflow and throttle control upgrades
- Designed for tuned and performance engines
- Improved response, drivability, and power delivery
- Compatible with modern ECU management systems