Performance Plenum

- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04

The 986 Boxster marked Porsche's return to a purpose built 2 seat roadster since the famed 550 Spyder. This liberating open cockpit platform was instrumental in saving Porsche from financial uncertainty and was Porsche highest volume seller from 1997 to 2003, until the Cayenne entered the Porsche line up.
The perfectly balanced mid engine 986 Boxster was designed to deliver driving excitement on sinuous back country roads while enabling the driver (and passenger) to literally take in the sights, sun and smells of the surrounding environment and listening to the intoxicating mechanical sounds of a flat 6 Boxer engine tones.
The Boxster experience can only be further heightened by adding improved performance. The IPD Plenums provide impressive the power gains throughout the entire power band making for an even more visceral Porsche driving experience.
All 986 Boxster IPD Plenum applications are designed to utilize the larger 74mm Porsche throttle body. The combination of the patented "Y" design of the IPD Plenum combined with a larger TB allow for improved air flow and intake air speed. The IPD Plenum is the absolute single best performance mod you can install on a Porsche Boxster, providing impressive power gains throughout the entire power band, especially in the midrange where we enjoy it most.
Installation of the 986 Boxster IPD Plenums comes with additional hardware and is relatively straight forward although IPD strongly recommend installation be performed by a trained Porsche technician.
The 74mm Boxster IPD Plenum and upgraded 74mm (from 68mm) throttle body package is recommended for Boxster enthusiasts looking for considerable performance gains. Performance gains can be felt throughout the entire power band making the Boxster driving experience even more visceral.
The IPD Boxster Plenum will provide the most impressive power gains of any engine upgrade available and will truly transform your Boxster driving experience. The 74mm IPD Plenum is the best Boxster modification on the market and will further compliment other mods such as exhaust, software and beyond.
Fits:
Porsche 986 Boxster S 3.2L 2000-04
Porsche 986 Boxster 2.7L 2000-04
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
IPDKIT98632
The product you are viewing cross references to these numbers
This kit is comprised of the following items:

- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
The 986 Boxster marked Porsche's return to a purpose built 2 seat roadster since the famed 550 Spyder. This liberating open cockpit platform was instrumental in saving Porsche from financial uncertainty and was Porsche highest volume seller from 1997 to 2003, until the Cayenne entered the Porsche line up.
The perfectly balanced mid engine 986 Boxster was designed to deliver driving excitement on sinuous back country roads while enabling the driver (and passenger) to literally take in the sights, sun and smells of the surrounding environment and listening to the intoxicating mechanical sounds of a flat 6 Boxer engine tones.
The Boxster experience can only be further heightened by adding improved performance. The IPD Plenums provide impressive the power gains throughout the entire power band making for an even more visceral Porsche driving experience.
All 986 Boxster IPD Plenum applications are designed to utilize the larger 74mm Porsche throttle body. The combination of the patented "Y" design of the IPD Plenum combined with a larger TB allow for improved air flow and intake air speed. The IPD Plenum is the absolute single best performance mod you can install on a Porsche Boxster, providing impressive power gains throughout the entire power band, especially in the midrange where we enjoy it most.
Installation of the 986 Boxster IPD Plenums comes with additional hardware and is relatively straight forward although IPD strongly recommend installation be performed by a trained Porsche technician.
The 74mm Boxster S IPD Plenum and upgraded 74mm (from 68mm) throttle body package is recommended for Boxster enthusiasts looking for considerable performance gains. Performance gains can be felt throughout the entire power band making the Boxster driving experience even more visceral.
The IPD Plenum will provide the most impressive power gains of any engine upgrade available and will truly transform your Boxster driving experience. The 74mm IPD Plenum is the best Boxster modification on the market and will further compliment other mods such as exhaust, software and beyond.
986 Boxster Competition 00-04 Plenum: TBA
Requires upgrading factory 68mm Thottle Body with 74mm Thottle Body
Fits:
Porsche 986 Boxster S 3.2L 2000-04
Porsche 986 Boxster 2.7L 2000-04
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
86174
The product you are viewing cross references to these numbers




- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12

In fuel injected engines, the throttle body is the part of the air intake system that controls the amount of air flowing into the engine, in response to driver accelerator pedal input in the main. The throttle body is usually located between the air filter box and the intake manifold, and it is usually attached to, or near, the mass airflow sensor.
The largest piece inside the throttle body is the throttle plate, which is a butterfly valve that regulates the airflow. Have a larger diameter throttle body produces more air flow with equals more power. The upgrades should be used in conjunction with the competition plenums.
This is a 74mm Throttle body.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99760511502
The product you are viewing cross references to these numbers




- Porsche Boxster 986 2.7L 1999-02
- Porsche Boxster S 986 3.2L 1999-02
- Porsche Boxster 986 2.7L 2003-04
- Porsche Boxster S 986 3.2L 2003-04
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12

In fuel injected engines, the throttle body is the part of the air intake system that controls the amount of air flowing into the engine, in response to driver accelerator pedal input in the main. The throttle body is usually located between the air filter box and the intake manifold, and it is usually attached to, or near, the mass airflow sensor.
The largest piece inside the throttle body is the throttle plate, which is a butterfly valve that regulates the airflow. Have a larger diameter throttle body produces more air flow with equals more power. The upgrades should be used in conjunction with the competition plenums.
This is a 74mm Throttle body.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99760511502
The product you are viewing cross references to these numbers



Performance Plenums – Maximise Airflow, Power & Efficiency for Your Porsche
A performance plenum is a critical upgrade for Porsche enthusiasts looking to improve throttle response, airflow efficiency, and overall engine performance. Sitting between the throttle body and intake runners, the plenum distributes incoming air evenly across all cylinders — ensuring consistent combustion and optimised power delivery.
At Design911, we offer a premium range of performance-engineered plenums designed specifically for Porsche models. Constructed from lightweight aluminium, carbon fibre, or composite materials, these units feature advanced internal flow geometry to reduce turbulence and increase air velocity.
Whether you’re enhancing a classic 911 or tuning a modern Cayman, our high-quality plenums are developed to deliver proven performance gains, sharper throttle response, and a more linear torque curve — perfect for both road and track use.
What Do Performance Plenums Do?
The plenum serves as an air distribution chamber that balances airflow between the cylinders. Upgrading to a performance plenum improves air charge efficiency, resulting in smoother engine breathing and increased power output.
Core Functions:
- Distribute
intake air evenly to all engine cylinders.
- Optimise
airflow dynamics for faster throttle response.
- Increase
air velocity and reduce pressure loss.
- Improve torque and mid-range performance.
- Enhance engine efficiency and fuel-air mixture stability.
A well-designed plenum ensures that every cylinder receives the right amount of air at the right time — unlocking smoother acceleration and more consistent power.
Why Do Plenums Fail or Require Replacement?
Over time, standard plenums can suffer from material fatigue, cracks, or restricted internal passages, all of which impact performance and reliability.
Common Causes of Failure Include:
- Cracks
or leaks from heat cycling and vibration.
- Carbon
build-up restricting airflow.
- Worn
gaskets or seals causing pressure loss.
- Plastic
deformation under extreme boost or temperature.
- Reduced efficiency due to outdated or restrictive design.
Signs of a failing plenum include loss of throttle response, poor fuel economy, uneven idle, or reduced torque. Replacing it with a performance-engineered unit restores full airflow efficiency and reliability.
Why Upgrade to a
Precision-Engineered Performance Plenum?
Upgrading your Porsche’s intake system with a high-performance
plenum enhances power delivery, throttle sharpness, and efficiency —
particularly when combined with a performance air intake and tuning.
Key Benefits:
- Increases horsepower and torque throughout the rev range.
- Delivers faster throttle response and improved drivability.
- Constructed from lightweight, heat-resistant materials.
- Improves airflow balance and reduces pressure drop.
- Direct-fit
compatibility for Porsche 911, Cayman, Boxster, and more.
- Ideal for performance tuning, track driving, and high-output builds.
Replacing restrictive intake components with a performance plenum unlocks your Porsche’s full potential, ensuring stronger mid-range power and greater engine efficiency.
Highlights:
- Performance-engineered plenums for Porsche tuning and upgrades.
- Improves airflow distribution, power delivery, and throttle response.
- Built from aluminium or carbon fibre for strength and weight reduction.
- Direct-fit installation with precision-sealed fittings.
- Perfect for high-performance, racing, or spirited road driving.
- Enhances engine sound and overall responsiveness.