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We are a dedicated team of engineers who embarked on an innovative venture: the creation of a revised carbon fiber intake system, akin to the one found in the esteemed GT4 RS model, tailored specifically for non-RS 981 and 718 Cayman models equipped with 6-cylinder engines.
We are pleased to provide you with insights into the project's inception and progress.
__________________ Performance and emotion enhancing lightweight manufacturer,
focused on detailed craftsmanship solutions.
The project's genesis was rooted in a fundamental question shared by many Porsche enthusiasts: What if the GT4 RS intake system could be seamlessly integrated into non-RS Cayman models?
Initially, this notion appeared straightforward due to Porsche's reputation for parts interchangeability. However, our journey took an unexpected turn as we began disassembling the GT4 RS intake and removed the top heat-shield from the engine bay.
The primary differentiator was immediately apparent—the throttle body's position. While the GT4 RS boasted a top-mounted throttle body, non-RS models featured a rear-facing one.
Top GT4 RS throttle body position
Rear GT4 throttle body position
Another challenge lay in the design of the window duct; the original system's configuration, involving a cutout of the interior plastic lining, was incompatible with our objective of ensuring full reversibility.
Does the 718 GT4 and its updated Manifold make it any eaiser?
The plenum in the 718 model actually sits a little bit higher than in the 981. We 3D scanned the 718 and therefore have the same boundary conditions for both.
Our system connects to the Y pipe, which has the same position and intake diameter on both models. Reason being they have the same air-filter housings.
To answer to your question: It didn't make any difference whilst designing the model.
We will test the fitment on a 981 with Clubsport runners and plenum shortly. Just to make sure.
According to the 3D model tho, our system clears the Dundon runners on a 981.
Upon obtaining both the GT4 RS and 718 GT4, we initiated the crucial 3D scanning phase. Initially, our focus was on scanning the rear space where the GT4 RS intake resides. This allowed us to define the boundary conditions and mounting points between the original intake and various elements such as side window openings, rollbars, and the engine bay's bodywork. Notably, the original intake ducts are mounted in such a way that it requires a cutout of the stock interior window lining. The rollbar sits quite low above the connecting ducts, so the ducts require a change in geometry to freely pass under. Furthermore, the bottom central component of the intake is securely fastened to the bodywork around the edge of a former heatshield on non RS models.
3D scanning of a GT4 RS scoop and duct
3D scanning of a GT4 RS scoop and duct
As we disassembled the original intake entirely, we uncovered some intriguing engineering aspects. Porsche's engineers had executed their work meticulously. The repositioning of the throttle body atop the engine was justified by the aim of achieving enhanced and more direct airflow from the scoops to the throttle body. The air's path through smartly designed filters, from bottom to top, streamlines its journey to the throttle body—a brilliant solution within a confined space. Surprisingly, the scoops themselves are hollow carbon fiber, affixed to the carbon fiber duct using double-sided tape. Additionally, the connecting duct features a specially designed silicone coupling to cover the interior lining cutout, while its shell comprises carbon fiber, albeit with a plastic insert for interfacing with the central piece. Within this central piece, three main components are evident, all constructed entirely of plastic: the bottom piece serving as a heatshield, the central piece housing the filters, and the upper piece sealing the entire assembly. The upper piece features a carbon fiber exterior for aesthetic purposes. Consequently, the sole disparity between non-Weissach and Weissach models is the absence of external scoops and the carbon fiber skin on the central piece, with all other aspects and materials remaining identical. We posit that this design distinction was primarily driven by financial considerations.
3D scanning of a GT4 RS upper central part separately
Moreover, we meticulously 3D scanned each component individually. Our objective was to mirror the external dimensions and design as closely as possible. Disassembling these components was not overly complex but did necessitate a modicum of automotive knowledge and access to appropriate tools. The 3D scanning process for the 718 GT4 was comparatively straightforward, yielding advantageous results. The consistency of rear side window boundaries, bottom mounting points, and the heatshield opening above the engine remained unchanged. Furthermore, we accurately identified the stock Y pipe's position and various boundary surfaces, including those of the stock plenum and rollbar. We also examined the air filter housings, although they would be rendered obsolete once our system was installed.
I’m looking forward to more updates! I do have a question for you. Your webpage says to contact you for more info on shipping out of Europe. Do you have a U.S. dealer ? Or will you be able to ship to the US ?
We do not yet have a dealer in the US. Until then, shipment is possible directly.
Shipping to the US unfortunately is not free as is throughout Europe. We have a contract with DHL and can provide you a quote.
We have tested the fitment of our system with a Clubsport plenum on the 981 GT4.
Our system clears the Clubsport plenum, but the collision is with the top mounted MAF sensor on the throttle body.
We are already in the process of mould modification.
Once the changes are made, our system will fit all combinations of aftermarket runners, plenums and throttle bodies.
We do not yet have a dealer in the US. Until then, shipment is possible directly.
Shipping to the US unfortunately is not free as is throughout Europe. We have a contract with DHL and can provide you a quote.
The modeling process for the scoops and ducts commenced with the utilization of a point cloud generated from a 3D scan. Our initial step involved considering specific boundary conditions, which encompassed the contour of the rear quarter window trim, the inner lining of the quarter side windows, and the original roll-bar. Importantly, these boundary conditions remained consistent across both the 981 and 718 models. It should be noted that we also accounted for aftermarket roll-bars in our analysis. The majority of these roll-bars do not deviate from the stock height, thus ensuring compatibility with our system, provided they do not extend lower than the stock GT4 and GT4 RS models.
Our overarching modeling approach adhered to the principle of faithfully reproducing the original design while simultaneously enhancing functionality and adapting the internal components to accommodate the new air routing configuration. In pursuit of our objective to offer a fully reversible system, we made a deliberate choice to avoid any interior lining modifications, such as the cutting required in the original GT4 RS system. Consequently, we opted to shift the location of the duct opening slightly towards the front. This strategic decision led to the adoption of an oval-shaped opening, chosen for its advantages in terms of manufacturing efficiency, ease of installation within the vehicle, and superior sealing capabilities between the outer and inner duct components. The cross-sectional area of the oval opening was optimized to be as large as possible while maintaining a smooth contour to facilitate laminar airflow. This design decision also ensured compatibility with both the inner lining and roll-bar. Importantly, the cross-sectional area of the ovals surpasses that of the intake cross-section of the Y pipe, resulting in a favorable pressure balance. The interface between the outer and inner ducts features a recessed coupling, resulting in a flush appearance with the connected pieces, thereby improving upon the original design.
The scoop was designed to snugly fit within the same U-shaped rubber channel that was previously occupied by the rear quarter glass. To install the scoop, one can easily remove the glass from the trim using a heat gun, and then insert the scoop with a touch of silicone adhesive.
It's important to note that the U-shaped rubber channel on its own ensures a secure and watertight seal.
With the oval opening positioned slightly forward, we decided to enlarge the scoop, effectively covering a greater surface area of the outer ducts.
This augmentation not only enhances aesthetics but also contributes to an increased ram air effect compared to the stock configuration.
3D model: left side scoop and ducts
3D model: right side scoop and ducts
The inner ducts were meticulously maintained to closely resemble the original design, with adjustments made to facilitate the redirection of airflow towards the front of the central intake housing.
The alteration in air routing will become more comprehensible once we delve into the description of the central intake housing. To minimize turbulence within the inner ducts, we incorporated 3D-printed inserts for precise air management.
3D model: left inner duct with a 3D printed insert
As previously mentioned, the Porsche GT4 RS features a top-mounted throttle body that leads to the plenum, runners, and ultimately into the engine cylinders. In contrast, all other 6-cylinder 981 and 718 Cayman models have a rear-facing throttle body, which aligns with their original air routing.
These models scoop air from the side vents behind the doors, directing it rearward before making a forward-facing turn toward the throttle body. Given our desire to retain the original throttle body and Y pipe, along with their respective positions, we undertook a complete redesign of the central portion of the intake system to accommodate this specific requirement.
This design choice was driven by the wide array of aftermarket plenums, runners, and throttle bodies available on the market. Our redesigned system can seamlessly function with these existing components, eliminating the need for additional parts to be included with our system (e.g., the GT4 RS throttle body and plenum).
Customers also have the option to revert to the original GT4 RS system, although it is notably more expensive.
The redesign focuses on the intake system's central section, where incoming air enters the front bottom part of the system (referred to as the bottom dirty chamber). It then passes through the air filters, transitioning into the top clean chamber before entering the trumpets located at the rear of the system.
Air flows through these trumpets, subsequently passing through the stock Y pipe and throttle body before entering the original plenum.
To make this configuration work seamlessly, the central system is constructed from four distinct parts. The upper skin part and upper structural part form the clean chamber, while the bottom structural part and bottom heat shield part create the dirty chamber.
The upper two parts are bonded together, as are the bottom two parts. These two assemblies are then bolted together, creating an airtight seal while securely holding the air filters and connecting ducts in place.
When selecting the air filters, we prioritized three key criteria. Firstly, the filters needed to be readily available worldwide on short notice. Secondly, they should be off-the-shelf filters, not custom-made, and ideally, they should have a larger surface area than the stock filters while fitting within the system's dimensions.
Fortunately, we identified suitable filters in the form of K&N 33-2304, which are also used in multiple Subaru models. These filters offer a greater surface area than the stock air filters in the GT4 RS, resulting in lower pressure drop and reduced restriction.
Significant attention was devoted to water management and drainage within the system's design. The system is engineered to ensure that water droplets entering the dirty chamber are effectively drained through the bottom heat shield piece, with drainage points strategically positioned away from the engine and other critical components.
The trumpets are inserted through the bottom assembly and securely held in place using plastic inserts and rubber O-rings, ultimately connecting to the stock Y pipe at the bottom.
Exploded view of the system
Decoupled upper and bottom assemblies
Last edited by Martin-Gold Leaf; 10-06-2023 at 10:52 AM.
08-31-2023, 11:56 AM
Porsche Cayman GT4 RS Style Carbon Fiber Intake
