Air intake components

Abstract

A method 100 of optimising a component for an air intake system (220, 300, 400, Figs. 2, 3, 4) for an internal combustion engine (ICE) being installed in an engine bay of a vehicle, the method compris

Description

FIELD OF THE INVENTION The present invention relates to components for air intake systems in internal combustion engines and associated methods of manufacturing. BACKGROUND Vehicles with internal combustion engines (ICEs) include an air intake system to direct air into the engine. The air intake system typically filters the air prior to directing the air into the engine. The filter is typically mounted within a component known as an “airbox”, after which the filtered air is directed through an outlet pipe towards the engine. For some applications, the stock filter, airbox, and / or outlet pipe may be adequate. However, for performance vehicles where there is a need to maximise engine power, these stock components are not optimised for increased performance. For this reason, it has been considered to replace one or more of these components in order to increase the airflow reaching the engine. For example, some have considered replacing the filter itself with an alternative filter with lower airflow resistance. However, the filter is not the only component affecting airflow into the engine. For example, the flow dynamics through the airbox, and / or the outlet pipe may also lead to unwanted resistance or turbulence that decreases airflow. Therefore, others have considered complete replacement of the airbox and outlet pipe with redesigned versions. However, these approaches have the following problems. Since stock components are designed specifically to work together with a specific engine within a specific engine bay, it is not a simple task to improve performance by simply replacing the stock components. Furthermore, since the stock components are already designed to fit within the relatively tight space of an engine bay, it is difficult to design replacement components that account for such obstructions, which leads to a large amount of trial and error in order to achieve components that both perform well and fit well within an engine bay. Therefore, it is an object of the present invention to address the problems discussed above. SUMMARY OF INVENTION According to an aspect of the present invention there is provided a method of optimising a component for an air intake system for an internal combustion engine (ICE), the ICE being installed in an engine bay of a vehicle, the method comprising: obtaining at least one 3D scan of the engine bay with the ICE installed; identifying, on the at least one 3D scan, one or more fixture points for securing the component within the engine bay, and one or more obstructions within the engine bay; generating, using a computer, a surface of the component, including generating an external surface that connects the one or more fixture points and does not intersect the one or more obstructions; and outputting a computer file representing the generated surface, the computer file containing instructions readable by a manufacturing system to enable manufacturing of the component based on the generated surface. Advantageously, by using at least one 3D scan it is possible to better determine the space available within the engine bay prior to designing the component. This allows the volume of the component to be maximized, while accounting for the specific requirements of the specific engine bay, such as avoiding obstructions and allowing for connection to any other components already mounted within the engine bay. By increasing the volume of the component, the cross-sectional area of flow-pathways through the component are also increased, which improves the peak airflow rate that is possible through the component. In this way the airflow within the components may be increased and the performance of the engine may be improved. The component may be partofan airbox (e.g., an airbox base and / or lid), an outlet pipe or any similar fluid orairconduit, for example. As used herein, the term “outlet pipe” or “outlet hose” preferably refers to any pipe or conduit that directs air from an outlet of an airbox lid to an inlet of a turbocharger. Where the component is an airbox lid, the fixture points may be attachment points for a suitable fastener or fixing (e.g., bolts or screws) to connect the airbox lid to the airbox base. Where the component is an outlet pipe, the fixture points may include mounting locations to attach the outlet pipe to the airbox (e.g., at a first end) or to another component such as a turbocharger (e.g., at a second end). The obstructions may include other components within the engine bay (e.g., the engine, turbocharger, battery, and / or conduits for air or fluid), and / or the bonnet. The method may be a computer implemented method. The computer file may be an STL file. The external surface of the component may comprise one or more grooves or indentations corresponding to the one or more obstructions within the engine bay. In this way, the volume occupied by the component can be increased while still preventing intersection with the one or more obstructions. As discussed above, an increased volume of the component may allow for improved airflow characteristics, during use. The grooves and / or indentations may allow a portion of the generated surface to have a constant separation (or “clearance”) with a corresponding obstruction. The region of separation may be referred to as a “buffer zone”. In typical components that are not optimised, the clearance may be about 30 mm. In the optimised components, the clearance can be between 5 and 10 mm). Preferably, the step of generating a surface with the computer includes adjusting an internal surface of the component for directing the flow of air through the component. The internal surface may be similar to the external surface, which may allow the component to be formed from a material with a substantially constant thickness. However, following generation of the external surface to avoid the one or more obstructions, it may contain indentations and / or grooves, that if left unmodified may lead to increased turbulence of air through the component. Therefore, the internal surface may be adjusted (e.g., at least in an airflow region of the component), in order to provide better airflow characteristics. Where the internal surface is adjusted, corresponding changes may be made to the external surface in order to facilitate this change (e.g., to provide a component with a constant thickness of material). Preferably, the method further comprises optimising the internal surface to achieve at least one of the following: increase an internal volume of the component; reduce airflow resistance through the component; and reduce turbulence through the component. It has been found that components in air intake systems with larger volumes generally allow for improved air flowrate to the engine; however, the shape and contours of the internal surface of the component also play an important role in improving airflow characteristics. Therefore, the surface of component may be adjusted to optimised performance based on one or more of these factors. Preferably, the method further comprises inputting into the computer the shape or dimensions of a pre-installed component, wherein the computer is configured to optimise the generated surface of the component relative to the pre-installed component. The preinstalled component may be a stock component included in the vehicle by its manufacturer. Preferably, the method further comprises running one or more computer simulations to determine the airflow resistance and / or turbulence of airflow though the component, and adjusting the generated surface based on the results of the one or more computer simulations. The computer simulations may include computational fluid dynamics (CFD) simulations. Advantageously, this allows the performance of the component to be determined and improved prior to manufacturing of the component, which reduces the time and expense resulting from physical testing of the manufactured components. The adjustment of the surface preferably includes adjustment to the internal surface, though it will be appreciated that the external surface may also be adjusted based on the results of the computer simulations. Preferably, adjusting the internal surface comprises providing one or more flow vanes or channels to direct airflow through the component. Preferably, the step of generating the surface with the computer comprises generating a plurality of guide curves that extend between the one or more fixture points, and defining a plurality of connecting surfaces between adjacent pairs of guide curves. The method may further comprise adjusting the guide curves and / or the connecting surfaces based on their proximity to the one or more obstructions. For example, if the guide curves and / or the connecting surfaces intersect one of the obstructions, then the guide curves and / or connecting surfaces may be adjusted to remove the intersection. Alternatively, even if there is no intersection, the guide curves and / or connecting surfaces may be adjusted to maintain a minimum spacing between the resulting surface and the one or more obstructions. The minimum spacing may be 10mm. A portion of the surface of the component may be adjusted to substantially follow a boundary of a buffer zone around one of the obstructions. The method may further comprise adjusting the radiusing and / or smoothing of the plurality of connecting surfaces, preferably wherein the surface comprises a minimum radius of curvature. By removing sharp edges or corners, the resistance and turbulence of the airflow during use may be reduced. Preferably, the at least one 3D scan of the engine bay includes: a first 3D scan that includes a pre-installed component; a second 3D scan where the pre-installed component has been at least partially removed. In this way, it is possible to have separate scans that include separate parts of the engine bay. This may allow the pre-installed component from the first 3D scan to be isolated from the engine bay and overlaid on the second 3D scan, which may facilitate the generation and / or optimisation of the surface of the (replacement) component. Preferably a plurality of 3D scans is taken while the pre-installed components (or sub-components) of the engine are removed, which may allow each of these components to be isolated, overlaid, and compared with replacement components. For example, there may be 3D scans corresponding to removal of the outlet pipe, the airbox lid, and optionally the airbox base. In the second 3D scan, the pre-installed component may be only partially removed. For example, in the second 3D scan, the airbox lid may be removed, and the airbox base may remain in place. Optionally a further 3D scan may be taken where the airbox base has also been removed. By gradually removing the components as 3D scans are taken, more flexibility is provided when the generating the surfaces using the computer. The component may comprise an airbox lid. Advantageously, by manufacturing an airbox lid it is possible to optimise airflowthrough the air-intake system, thereby improving performance (e.g., relative to a stock airbox lid). The component being optimised may be only the airbox lid (i.e., without an airbox base). Alternatively, the component may be the entire airbox (i.e., including the airbox base as well as the airbox lid). Where the component comprises an airbox lid, the at least one 3D scan of the engine bay may include a scan or model of an airbox base. The airbox base may be a stock airbox base (e.g., an airbox base fitted to the car by the manufacturer). Alternatively, the airbox base may be an aftermarket airbox base (e.g., from which a lid has been removed). Advantageously, it has been found that most performance improvements can be made by fitting a replacement airbox lid, without the need to replace the entire airbox (including the airbox base). This is because the airbox base (which may include a panel filter to filter incoming air) is already reasonably optimised by the manufacturer for the particular vehicle. Furthermore, since the particular airbox base (and particular filter) is related to the frontal pressure at the air inlet to the vehicle, it is not always considered feasible to replace the airbox base, since this may lead to a performance reduction. Therefore, by including a scan or model of the airbox base within the 3D scan of the engine bay, and designing an airbox lid to fit onto it, the number of components that need to be removed and replaced is reduced, without any significant reduction of performance improvements. Where the component is an airbox lid, the fixture points may be defined relative to the 3D scan of the engine bay and / or fixture points on the airbox base. The component may comprise an outlet pipe. Typical outlet pipes are not optimised to improve airflow. Therefore, by using the method to manufacture an outlet pipe, the resistance to airflow through the outlet pipe can be reduced and the performance of the vehicle may be enhanced. The component may be (e.g., only) the outlet pipe. Alternatively, the component may include both the outlet pipe together with another component. Some engines may include more than one outlet pipe, such as to direct air from different airboxes to the turbocharger. As used herein, where two such components are used, either or both of them may be referred to using any of the terms “outlet pipe”, “outlet hose”, “inlet pipe” or “inlet hose”. Stock outlet pipes typically have a restricted diameter and provide flexibility by using corrugations in the surface, which decreases airflow and increases turbulence through the stock component. Therefore, where the component is an outlet pipe, the component preferably does not have corrugations on at least an internal surface. The component may comprise an adaptor configured to facilitate a connection between other components in the air intake system. For example, in typical air intake systems, an aluminium adaptor may be used to connect the outlet pipe to other components in the engine bay (e.g., the turbocharger). However, these adaptors are designed specifically for the non-optimised stock components and cannot be used with optimised components. Preferably the adaptor comprises a flexible material. The flexible material may comprise TPU (e.g., if manufactured by 3D printing). The flexible material may comprise silicon. Where the optimised outlet pipe does not include corrugations to provide flexibility, by forming the adaptor from a flexible material, the outlet pipe can be more easily mounted within the engine bay. The generated surface may include a tubular portion, and a central location of the tubular portion may be arranged to coincide with a fixed location for a mass-airflow sensor within the engine bay. Typically, mass-airflow sensors are mounted at a predetermined location within the airflow pathway in order to obtain accurate measurements, such as within the centre of the channel. Therefore, the surface may be arranged so that the mass-airflow sensor is located at the centre of the channel during use. Preferably, the surface is generated to have a minimum separation with the one or more obstructions of 10 mm or less, preferably 5 mm or less. Advantageously, by generating a surface that has a minimum separation of 10 mm or less, it is possible to maximize the volume of the engine component (thereby improving performance) without substantially increasing the risk of collision between components and / or difficulty of installation. As used herein, the term “minimum separation” preferably indicates that the surface includes a portion that is separated from the obstruction by less than the specified value. The region around the obstruction may be referred to as a “buffer zone”. According to another aspect of the present invention there is provided a method of manufacturing an optimised component for an air intake system of an internal combustion engine (ICE), the method comprising: inputting the outputted computer file described above and herein to a manufacturing system; and controlling the manufacturing system to form the component based on the instructions contained in the computer file. The manufacturing system may contain any equipment or apparatus that is suitable for manufacturing the optimised component. For example, it may include CNC machines, moulding apparatus, 3D printers, vacuum forming apparatus, and / or casting apparatus. The manufacturing system can include automated apparatuses. Alternatively or additionally, manual steps may be used to manufacture the optimised component. Preferably, the step of manufacturing the component comprises: manufacturing a mould based on the generated surface stored in the computer file; and moulding the optimised component using the manufactured mould. Advantageously, moulding allows for a variety of shapes to be manufactured quickly and repeatably. The method may further comprise adjusting the generated surface to optimise release of the optimised component from the mould. For example, the generated surface may be adjusted so that it can be released from the mould along a particular axis. The surface may be adjusted to remove any deep channels that may prevent removal of the component from the mould. Preferably, the optimised component comprises carbon fibre. By using carbon fibre as a material, the resulting components can be particularly strong. In addition, carbon fibre conducts less heat than stock parts; by improving the heat management within the air intake system, the engine can maintain a higher power output during use. For example, stock components lose 16HP after three runs simply from “heat soak”, whereas a carbon fibre component may lose 1 HP or less. The method may comprise manufacturing a test component based on the generated surface, performing one or more airflow tests on the test component, and adjusting the surface based on the results of the tests. The manufacturing of the test component may comprise 3D printing. The component may be made of ABS (e.g., for the airbox and / or outlet pipe) or TPU (e.g., for the adaptor). This may allow the test component to be cheaply and quickly manufactured to enable testing (without needing to mass produce the components or produce specific moulds). The testing may include wind tunnel testing or any other suitable types of physical tests. If the tests determine that improvements can still be made to the component, then the (e.g., internal) surface may be updated. According to another aspect of the present invention there is provided a component for an engine air intake system manufactured using the method as described above and herein. Also provided is a vehicle comprising this component. The vehicle may be tested following installation of the component to verify that performance has improved. This may include dyno testing or any other similar type of test. According to another aspect of the present invention there is provided a vehicle with an internal combustion engine (ICE) installed in its engine bay, the engine bay comprising: one or more fixture points, and one or more obstructions; a component for an air intake system for the ICE, the component comprising an external surface defining an internal volume, the component secured within the engine bay at the one or more fixture points, wherein a minimum separation between the surface and the one or more obstructions is 10 mm or less. It will be understood by a skilled person that any device or system feature described herein may be provided as a method feature, and vice versa. It will also be understood that particular combinations of the various features described and defined in any aspects herein can be implemented and / or supplied and / or used independently. Moreover, it will be understood that the present invention is described herein purely by way of example, and modifications of detail can be made within the scope of the invention. BRIEF DESCRIPTION OF DRAWINGS One or more embodiments will now be described, purely by way of example, with reference to the accompanying figures, in which: Figure 1 shows an engine bay of a vehicle including an internal combustion engine, airboxes, an outlet hose and an outlet pipe; Figures 2A to 2D show views of a stock airbox lid that may be used in the engine bay; Figures 3A and 3B show views of a stock outlet hose that may be used in the engine bay; Figures 4A to 4C show views of a stock outlet pipe that may be used in the engine bay; Figure 5 shows the steps of a method of optimising and manufacturing a component according to the present invention; Figures 6A to 6F show 3D-scans of the engine bay taken while carrying out the method shown in Figure 5; Figures 7A to 7C show the surfaces of the components located within the 3D scans; Figures 8A and 8B show surfaces of an airbox lid and outlet pipe that are generated using a computer; Figures 9A and 9B show examples of a test airbox lid and outlet pipe that may be manufactured using the method; Figures 10A to 10D show an example of an optimised airbox lid manufactured using carbon fibre moulding; Figures 11Ato 11C show an example of an optimised outlet pipe manufactured using carbon fibre moulding; and Figures 12Aand 12B show an optimised outlet hose having an adaptor. DETAILED DESCRIPTION In the following description and accompanying drawings, corresponding features are preferably identified using corresponding reference numerals to avoid the need to describe said common features in detail for each and every embodiment. Figure 1 shows typical internal components of an engine bay 50. The engine bay houses an internal combustion engine (ICE) 52. Air enters the engine bay 50 through the front radiator grille and into an air scoop (not shown), which directs the air into an airbox 200’. In the example shown, the engine bay 50 includes two airboxes 200’-1, 200’-2, though it will be appreciated that some vehicles only include one. Each airbox 200’ includes a filtration component to filter the incoming air. In this example, the filtration component is a panel filter 212’ (not shown in Figure 1) having a substantially 2-dimensional surface. The airbox 200’ includes an airbox base 210’ (not shown in Figure 1) that holds the panel filter 212’. Attached on top of the airbox base 210’ is an airbox lid 220’ which directs the air passing through the panel filter 212’ out of the airbox 200’. In particular, the first airbox 200’-1 directs air into a first outlet pipe 300’, and the second airbox 200’-2 directs air into a second outlet pipe 400’. For clarity, the first outlet pipe 300’ will be referred to herein as an “outlet hose” and the second outlet pipe 400’ will be referred to herein as the “outlet pipe”, though it will be appreciated that different terminology can be used to refer to these components. A flowrate sensor may be positioned in the outlet pipe 400’ so that the airflow can be monitored. The outlet hose 300’ directs the air into a turbocharger (not visible in Figure 1). In some cases, an adaptor 350’ is required to facilitate connection between the outlet hose 300’ and the turbocharger. The engine bay 50 may include several other components such as a battery, wiring, and conduits for fluid or air, though these are not specifically labelled in Figure 1. As shown in Figure 1, this particular engine bay 50 includes a bracket 72 that connects to corresponding brackets 422’ of the outlet pipe 400’, and support braces 71 extending over the top of the engine bay 50. It will be understood that the particular configuration and positions of the components within the engine bay 50 will vary from vehicle to vehicle. For example, several brackets and braces may be located in different places. The grille, air scoop, airboxes 200’ (including airbox base 210 and airbox lid 220’), outlet hose 300’, outlet pipe 400’ together with any necessary adaptors, form part of an air intake system, and “stock” versions of these components are provided by the vehicle manufacturer. Figures 2A to 2D show different views of a stock airbox lid 220’. In this example, the airbox lid 220’ corresponds to the first (LHS) airbox lid 22O’-1 shown in Figure 1, though it will be appreciated that the second (RHS) airbox lid 22O’-2 may have a similar construction. The airbox lid 220’ has an external surface 242’ and an internal surface 244’ (shown particularly in Figure 2C). When the airbox lid 220’ is connected to a corresponding airbox base 210’ (not shown in Figure 2) an internal volume in enclosed. To allow the airbox lid 220’ to be connected to the airbox base 210’, a rim 222’ is provided with a shape corresponding to the perimeter of the airbox base 210’. Several fixture holes 224’ are provided (only some labelled) that allow the rim 222’ to be bolted to the airbox base 210’ (which has corresponding fixture holes). During use, airflows through a panel filter212’ in the airbox base 210’ and into the internal volume of the airbox lid 220’. From here, the air flows out of an outlet opening 226’, which is connectable to the outlet hose 300’ (or for the second airbox lid 22O’-2, the outlet pipe 400’), as discussed below. Figures 3A and 3B show different views of a stock outlet hose 300’. The outlet hose 300’ has a tubular body 310’ having a first end 310a’ and a second end 31 Ob’. The outlet hose 300 has an external surface 342’ and an internal surface 344’ (though the internal surface is not visible in Figure 3). The first end 310a’ has an inlet opening 326a’ that is connectable to the outlet opening 226’ of the first airbox lid 22O’-1. The second end 310b’ has an outlet opening 326b’ that is connectable to a turbocharger. To enable these ends 310a’, 31 Ob’ to be easily connected within the engine bay, the tubular body 310’ includes corrugated portions 312a’, 312b’ at the respective ends, which allow the ends of the tubular body 310’ to flex relative to each other. To facilitate connection of the outlet hose 300’ to the turbocharger, an adaptor 350’ made of aluminium is provided at the second end 310b’. Figures 4Ato 4C show different views of a stock outlet pipe 400’. The outlet pipe 400’ has a tubular body 410’ having a first end 410a’ and a second end 41 Ob’. The outlet pipe 400’ has an external surface 442’ and an internal surface 444’ (though the internal surface is not visible in Figure 4). The first end 410a’ has an inlet opening 426a’ that is connectable to the outlet opening 226’ of the airbox lid 220’-2. The second end 410b’ has an outlet opening 426b’. To enable these ends 410a’, 410b’ to be easily connected within the engine bay, the tubular body 410’ includes corrugated portions 412a’, 412b’ at the respective ends, which allow the ends of the tubular body 410’ to flex relative to each other. Additionally, to support the outlet pipe 400’ along its length, two fixture brackets 422’ are provided, each having a corresponding fixture hole 424’. When the outlet pipe 400’ is mounted within the engine bay, bolts are inserted through the fixture holes 424’ to secure the outlet pipe 400’ in place to the brackets 72 in the engine bay 50. Similarly to the outlet hose 300’, the outlet pipe 400’ may be fitted with an aluminium adaptor 450’ to facilitate mounting of the outlet pipe 400’ in the engine bay. However, these stock components 200’, 300’, 400’ are not typically optimised to maximise the performance of the vehicle. For example, the volume of the stock components 220’, 300’, 400’ is not particularly large, which may lead to higher airflow resistance through the components. Furthermore, the corrugated portions 312’, 412’ on the outlet hose 400’ and outlet pipe 300’ can lead to substantial turbulence of the air, which further reduces the performance of the vehicle. Therefore, it has been considered to replace one or more of these components with replacement components, so as to improve vehicle performance. Normally, this is achieved by removing the existing stock component, and designing a replacement component (e.g., in CAD software), manufacturing the component, and installing it within the engine bay 50. However, this is not a simple task. As can be seen from Figure 1, the engine bay 50 contains a large number of other components and structures that limit the space available for modified components. It is difficult when designing replacement components to ensure that they will not collide with other parts within the engine bay 50. As a result, the design steps often need to be iterated several times, where parts are manufactured, installed and tested several times to ensure that they fit within in the engine bay 50 and do not harm performance of the vehicle. Therefore, to address these difficulties, an improved method 100 of designing and manufacturing these components will now be discussed. While the method 100 generally relates to replacement of the airbox lid 220’, outlet hose 300’ and outlet pipe 400’ it will be appreciated that the method 100 could also be applied to other components of the air intake system. Examples of airbox lids 220, outlet hoses 300 and outlet pipes 400 (and corresponding adaptors) manufactured according to this method will be described in more detail in relation to Figures 9 to 12. Figure 5 shows a flow diagram of the method 100 of manufacturing a component for an air intake system for an internal combustion engine (ICE). At step 110, at least one 3D scan of the engine bay is obtained. More specifically, this includes obtaining a first 3D scan is taken of the engine bay without any components removed. An example of this 3D scan is shown in Figure 6A, where all of the existing components (e.g., stock components, or alternative aftermarket components) are still present, such as the existing outlet hose 300’, outlet pipe 400’ and airbox lids 22O’-1,22O’-2. Then, the components are removed one-at-a-time, and further 3D scans are taken. These further 3D scans include scans of the engine bay, and 3D scans of the removed components in isolation. For example, Figure 6B shows a 3D scan of the removed outlet hose 300’ in isolation, and Figure 6C shows a 3D scan of the removed outlet pipe 400’ in isolation. Figure 6D shows a scan of the engine bay where the outlet hose 300’, the outlet pipe 400’ and both of the airbox lids 220’ have been removed. This 3D scan may be used to provide a “virtual” model of an engine bay within which the replacement components can be designed. The scans of the removed components can be used as reference to allow for comparison with the replacement components during the design process. At step 120, fixture points 60 are identified on the 3D scans. For the airbox lids 220, the fixture points 60 include fastening locations 61 where the airbox lid 220 is bolted to the engine bay or the airbox base (as particularly shown in Figure 6F). For the outlet hose, the fixture points 60 include a fastening location (not shown) where the outlet hose is attached to the turbocharger inlet. The fixture points 60 for the outlet pipe may also include one or more bolting locations 64 where brackets of the outlet pipe are bolted to a corresponding bracket 72 within the engine bay 50 (as particularly shown in Figures 6D). The fixture points 60 (when considering any of the airbox lids, outlet hose or the outlet pipe) may also include a connection location 62 with the airbox lid (as particularly shown in Figures 6E and 6F); where there is a desire to change only one of the airbox lid and the outlet pipe or outlet hose, it may be desirable to keep this connection location in the same place. Where both the airbox lid is being replaced together with its corresponding outlet hose or outlet pipe, this connection location can be varied in order to optimise flow characteristics through the air intake system (as discussed further below). However, by keeping the connection location 62 constant, it is possible to replace only one of these components while retaining compatibility with the stock components. At step 130, obstructions 70 are identified on the 3D scans. The obstructions 70 generally relate to any object within the engine bay 50 that may constrain the position, shape or size of the component. For example, the obstructions 70 may include other components within the engine bay 50, such as the engine 52, turbocharger, air scoop or battery. Additionally, the engine bay 50 may include support braces 71 or brackets 72, wiring, or conduits for fluid or air that already have fixed positions. Likewise, the bonnet (in its closed position) is considered as an obstruction 70, since it limits the vertical height of the components. Collectively, these components can be marked as obstructions 70 within the engine bay 50, and act as a constraint for how the replacement component is designed and manufactured. For example, as shown in Figure 6D, the bracing 71 and bracket 72 are marked as obstructions 70, but it will be appreciated that other obstructions 70 may be present, and that different vehicles may have a different configuration of obstructions 70. At step 140, a surface of the component is generated, which may include the following. At step 142, an external surface of the component is generated. This may be performed in CAD software. The external surface connects to the one or more fixture points 60 (discussed above), which ensures that the replacement component can be mounted within the specific engine bay that was 3D-scanned at step 110. Accordingly, the external surface may be generated to include brackets and / or bolt holes corresponding to the fixture points. The external surface is also generated to avoid intersection with the one or more obstructions 70. Since the generation process is performed using the 3D-scans obtained in step 110 with obstructions 70 marked in step 130, it is possible to ensure that the generated surface avoids all of the obstructions 70. For example, as shown in Figures 7A to 7C, the surfaces of the components can be placed within the 3D model or 3D scan of the (empty) engine bay 50, and thus it is possible to confirm its placement in the engine bay 50 without needing to manufacture the component. Furthermore, as particularly shown in Figure 7C the shape of the replacement component can be overlaid with the shape of the stock component to allow for a comparison of the surfaces. Since the generation process utilised the 3D scans obtained in step 110, it is possible to eliminate the trial-and-error process that is usually required when designing most replacement components on the market. Furthermore, as a result of using the 3D scans to generate the external surface, the volume of the component can be maximised without leading to an intersection, which (as discussed below), can improve the flow characteristics within the replacement component. In addition to avoiding direct intersection with the obstructions 70, the external surface may be generated to maintain a predetermined clearance around each of the obstructions 70. This aids with installation of the replacement components within the engine bay 50 and reduces the likelihood of collisions with the replacement component such as during vibrations or relative movement. In this example, the predetermined clearance is selected to be 10 mm, though other values can be used. For example, the generated surface may be modified to follow a contour located at the predetermined distance from the obstruction 70. The generated surface may have a portion where the separation between the surface and one of the obstructions remains substantially constant. This region of separation may be referred to as a “buffer zone”. This may result in grooves and / or indentations being formed on the external surface, in order to prevent the external surface from entering the “buffer zone” around each of the obstructions 70. Practically, the generation of the external surface may include generating a plurality of guide curves 90 the extend between the one or more fixture points 60. Subsequently, adjacent pairs of guide curves 90 are then connected with surfaces 92. This enables fixed locations (along the guide curves 90) to be maintained, while still enabling a smooth shape to be created when they are connected with the connecting surfaces 92. These guide curves 90 and connecting surfaces 92 are best appreciated with reference to Figures 8Aand 8B, which show models of the airbox lid 220-2 and outlet pipe 300-2. In these models, the guide curves are solid lines, with connecting surfaces extending between adjacent solid lines, though only some of these lines and surfaces have been labelled. Once the surface has been initially generated in this way, either the guide curves 90 or the connecting surfaces 92 can be adjusted to increase the volume and avoid intersections (or near-intersections) with the obstructions 70. Where more detailed geometry is required to avoid an obstruction 70 (e.g., to provide a groove or indentation), further guide curves 90 and connecting surfaces 92 may be added to the surface. Radiusing and / or smoothing of the connecting surfaces can be adjusted at this stage, such as to require a minimum radius of curvature. As discussed later, a smoother external surface is likely to result in better flow characteristics for the corresponding internal surface. As a result of step 142, an external surface of the component is provided that allows the component to fit within the engine bay 50. Due to the identification of obstructions 70 and corresponding surface adjustments, the external surface of the component can enclose a larger volume, and thus may allow for increased airflow through the component. For example, where the component is the outlet pipe 400, the outlet pipe 400 may have a larger cross-sectional area and / or may have a more uniform cross-sectional area along its length. Therefore, at this stage the method can proceed to step 160 (discussed below) to allow the component to be manufactured. Examples of the components produced at this stage in the method are shown in Figures 9A and 9B. Figure 9A shows an (RHS) airbox lid 220-2 and Figure 9B shows an outlet pipe 400. These components may be referred to as “test components”. As discussed later in relation to steps 170 and 180, test components can be manufactured more cheaply than the final production components, such as using 3D printing. This allows for initial physical tests to be performed to determine the flow characteristics through the component. However, while the external shape of the components has been adjusted based on external constraints (i.e., the fixture points 60 and obstructions 70), the shape of the internal surface of the component can be further modified in order to further improve flow characteristics. For example, the grooves or indentations discussed above may cause turbulence within the component, such as due to sharp corners or constrictions to the flow channels. Therefore, at step 144, an internal surface of the component may be adjusted. Initially, the internal surface is substantially the same as the external surface discussed above (i.e., when accounting for the thickness of the component). Therefore, any grooves or indentations on the external surface will initially also be presented on the internal surface. However, such shapes are not necessarily optimal for airflow, so adjustments are made with the aim of increasing the overall internal volume of the component (which as discussed above, improves airflow), as well as reducing turbulence and resistance to the airflow during use. This step may be performed using CAD software. The adjustment may include adjustment of the guide curves and connecting surfaces discussed above, in order to remove sharp corners that are likely to lead to turbulence. The adjustment may include providing flow vanes or channels through the component to direct airflow through the component. While it is the internal surface that is being adjusted during step 144 to improve airflow characteristics, it will be appreciated that corresponding changes may be made to the external surface to facilitate these changes (e.g., to maintain a constant thickness of the component). In this instance, it is verified that any external adjustments do not lead to intersections with the obstructions 70. At step 146, computer simulations are run to determine the airflow resistance and / or turbulence of airflowthrough the component. Simulations may also be run for the stock component using the surfaces obtained in the 3D scans. This allows for comparison with the stock components. The simulations may allow locations of sub-optimal flow to be identified. Once the results of the simulations are obtained, the method may return to step 144, where the internal surface is adjusted to optimise the airflow through the component. The way this may be achieved depends on the particular airflow problems identified. For example, it may involve smoothing sharp corners of the internal surface or adjusting the existing surface so that there is a minimum radius of curvature. In some cases, flow vanes or channels are provided on the internal surface to actively direct the airflow in a particular direction through the component. This encourages laminar flow through the component thereby reducing energy losses due to turbulence. Steps 144 and 146 may be iterated to assess the effectiveness of the adjusted internal surface and to make further improvements to airflow as necessary. The results of the simulations may be compared to results from the stock component to verify that overall performance improvements have been made. Other factors may need to be considered when generating the surface of the component. For example, a mass airflow sensor is typically inserted into the outlet pipe to monitor flow of air into the turbocharger or engine. For this sensor to provide accurate measurements, it needs to be located in the centre of the tubular body. Therefore, the surface (external and / or internal) may be generated and / or adjusted so that the position of the flow sensor remains within the centre of the tubular body. Likewise, changes may be made to the surface to facilitate manufacturing, such as the moulding process that is described later. Where moulding is used, the surface may adjusted to optimise release of the component from the mould, such as removing the presence of any deep channels that may prevent removal of the component from its mould. Once step 140 is completed to generate a surface of the component, at step 160, a computer file is outputted that represents the generated surface. In this case, the computer file is an STL file, though it will be appreciated that any file format may be used provided that it is readable by a manufacturing system to manufacture the component. At step 170, a test component is manufactured using the outputted computer file. There are several ways that the component could be manufactured based on the STL file, such as 3D printing, vacuum forming, casting or machining. Typically, the test component is manufactured 3D printing, which enables to the components to be quickly made to enable rapid testing. For the airbox lids 220 and outlet pipes 400, the 3D printing may use an ABS material. The test airbox lid 220-2 and test outlet pipe 400 shown in Figures 9Aand 9B are manufactured using 3D printing. At step 180, the test component may be tested. This may allow performance of the component to be verified prior to mass producing the component. The testing may include wind tunnel testing to assess the airflow characteristics through the component, or any other suitable types of tests. For airflow testing, physical tests are preferred to computer-based tests (e.g., using CFD), since they provide a better indication of the actual performance of the components, during use. If the tests verify that the airflow characteristics have improved (e.g., relative to the stock parts), and that the components can be manufactured, then the component may proceed to step 190. Alternatively, if performance does not substantially improve, or if it decided that further improvements can be made, then the method returns to step 140 to adjust the surface further. Several iterations may be required in order to arrive at a finalised surface Where the final components are manufactured by a particular method, the method may include verifying that the components can be manufactured using that method. Where moulding is used to manufacture the component, the surface may be adjusted to optimise release of the component from the mould. For example, the surface of the airbox lid 220 around the outlet opening 226 may be smoothed to aid removal of the component from the mould. As shown in Figure 2D, the stock airbox lid 220’ has a deep channel around the outlet opening 226’ which may lead to difficulties in removing the component if manufactured using a mould. As shown in Figure 10D (discussed later in more detail), this channel has been removed in the airbox lid 220, which may allow for the airbox lid 220 to be manufactured more easily using moulding. At step 190, one or more of the components are manufactured based on the generated (finalised) surface. Similarly to the test component, there are several ways that the component could be manufactured based on the STL file, such as 3D printing, vacuum forming, casting or machining. However, a preferred method discussed below involves moulding the component using a carbon fibre material. By using moulding to manufacture the component, a large number of components can be manufactured with exactly the same shape at low cost. More specifically, a mould is manufactured based on the generated surface, and one or more of the components are moulded using the mould. For example, the mould may have two parts. An internal part may have an external surface having a shape corresponding to the internal surface of the component; an external part may have an internal surface having a shape corresponding to the external surface of the component. This means that when the component is manufactured between the two parts of the mould, the final shape exactly matches the surface determined in step 140. The optimised component is moulded using a carbon fibre material. More specifically, a layer of resin material containing carbon fibres may be pressed around a mould and subsequently cured to solidify the resin material. By using carbon fibre material in the optimised component, the component is both lightweight and also relatively strong. As a further benefit, carbon fibre conducts less heat than the plastic materials used in the stock components. It has been found during testing of stock components that 16HP is lost after only three test runs due to heat soak. Whereas the carbon fibre components are better insulated and lose 1 HP or less in three test runs. Now that the method 100 has been described, various examples of components manufactured using the method will now be discussed. Corresponding reference numerals have been used to refer to both the optimised components 220, 300. 400, and the stock components 220’, 300’, 400’. Therefore for brevity, features that are common to the components will not necessarily be described in detail again. Figures 10A to 10D show different views of an optimised airbox lid 220 that may be manufactured using the method 100 discussed above. In this example, the airbox lid 220 corresponds to the first (LHS) airbox lid 220-1, though it will be appreciated that the second (RHS) airbox lid may have similar features. The airbox lid 220 has an external surface 244 and an internal surface 242 (shown particularly in Figure 10C). When the airbox lid 220 is connected to a corresponding airbox base (not shown) an internal volume in enclosed. The airbox base may be a stock airbox base including its stock filter; alternatively, the airbox base can be a custom airbox base, which may be optimised using the method described above. To allow the airbox lid 220 to be connected to the airbox base 210, a rim 222 is provided with a shape corresponding to the perimeter of the airbox base. Several fixture holes 224 are provided (only some labelled) that allow the rim to be bolted to the airbox base (which may have corresponding fixture holes). During use, air flows through a panel filter in the airbox base 210 and into the internal volume of the airbox lid 220. From here the air flows out of an outlet opening 226, which is connectable to an outlet hose 300 (or for the second airbox lid 220-2, the outlet pipe 400), as discussed below. Figures 11A to 11D show different views of an optimised outlet pipe 400. The outlet pipe 400 has a tubular body 410 having a first end 410a and a second end 410b. The first end 410a has an inlet opening 426a that is connectable to the outlet opening 226 of the airbox lid 220-2. The second end 410b has an outlet opening 426b. Additionally, to support the outlet pipe 400 along its length, two fixture brackets 422 are provided, each having a corresponding fixture hole 424. When the outlet pipe 400 is mounted within the engine bay, bolts are inserted through the fixture holes 424 to secure the outlet pipe 400 to the support brackets 72. As shown in Figures 11A to 11C, the outlet pipe 400 includes one or more grooves and indentations 446. As discussed above, these allow the volume of the outlet pipe to be increased (and airflow performance to be improved) without intersecting with any of the obstructions 70 within the engine bay. Another difference between the optimised outlet pipe 400 and the stock outlet pipe 400’ is that the optimised outlet pipe 400 does not include any corrugations. By omitting the corrugations, the turbulence and airflow resistance through the air intake system is reduced, which improves performance of the vehicle. Figures 12A and 12B show different views of an optimised outlet hose 300. Compared to the stock outlet hose 300’ shown in Figures 3A and 3B, the optimised outlet hose 300 does not include any corrugations, but is formed from a single piece of material having a tubular body 310 with a wider diameter than the tubular body 310’ of the stock outlet pipe. To attach the outlet hose 300 to the turbocharger, a corresponding adaptor 350 is designed and manufactured. This process may also follow the method 100 described above in relation to Figure 5. Where a test adaptor 350 is manufactured, it may be 3D-printed from TPU. In the final component, the adaptor 350 may be manufactured from silicon. These materials provide flexibility that allows the outlet hose 300 to be connected between the airbox lid 220-1 and the turbocharger, without the need for corrugations. By removing the corrugations, the air passing through the outlet hose 300 is less turbulent, thereby improving performance of the vehicle. While an optimised adaptor 350 is described above in relation to the outlet hose 300, it will be appreciated that an adaptor may be used with the outlet pipe 400. While the foregoing is directed to exemplary embodiments of the present invention, it will be understood that the present invention is described herein purely by way of example, and modifications of detail can be made within the scope of the invention. Moreover, other and further embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and may be devised without departing from the basic scope thereof, which is determined by the claims that follow.

Claims

1. A method of optimising a component for an air intake system for an internal combustion engine (ICE), the ICE being installed in an engine bay of a vehicle, the method comprising:obtaining at least one 3D scan of the engine bay with the ICE installed;identifying, on the at least one 3D scan, one or more fixture points for securing the component within the engine bay, and one or more obstructions within the engine bay;generating, using a computer, a surface of the component, including generating an external surface that connects the one or more fixture points and does not intersect the one or more obstructions; andoutputting a computer file representing the generated surface, the computer file containing instructions readable by a manufacturing system to enable manufacturing of the component based on the generated surface.

2. The method of claim 1, wherein the external surface of the component comprises one or more grooves or indentations corresponding to the one or more obstructions within the engine bay.

3. The method of claim 1 or 2, wherein the step of generating a surface with the computer includes adjusting an internal surface of the component for directing the flow of air through the component.

4. The method of claim 3, further comprising optimising the internal surface to achieve at least one of the following: increase an internal volume of the component; reduce airflow resistance through the component; and reduce turbulence through the component.

5. The method of claim 4, further comprising inputting into the computer dimensions of a pre-installed component, wherein the computer is configured to optimise the generated surface of the component relative to the pre-installed component.

6. The method of any of claims 3 to 5, further comprising running one or more computer simulations to determine the airflow resistance and / or turbulence of airflow though the component, and adjusting the generated surface based on the results of the one or more computer simulations.

7. The method of any of claims 3 to 6, wherein adjusting the internal surface comprises providing one or more flow vanes or channels to direct airflow through the component.

8. The method of any preceding claim, wherein the step of generating the surface with the computer comprises generating a plurality of guide curves that extend between the one or more fixture points, and defining a plurality of connecting surfaces between adjacent pairs of guide curves.

9. The method of claim 8, further comprising adjusting the guide curves and / or the connecting surfaces based on their proximity to the one or more obstructions.

10. The method of claim 8 or 9, further comprising adjusting the radiusing and / or smoothing of the plurality of connecting surfaces, preferably wherein the surface comprises a minimum radius of curvature.

11. The method of any preceding claim, wherein the at least one 3D scan of the engine bay includes:a first 3D scan that includes a pre-installed component;a second 3D scan where the pre-installed component has been at least partially removed.

12. The method of any preceding claim, wherein the component comprises an airbox lid.

13. The method of claim 12, wherein the at least one 3D scan of the engine bay includes a scan or model of an airbox base.

14. The method of any of claims 1 to 11, wherein the component comprises an outlet pipe.

15. The method of any of claims 1 to 11, wherein the component comprises an adaptor configured to facilitate a connection between other components in the air intake system.

16. The method of any preceding claim, wherein the generated surface includes a tubular portion, wherein a central location of the tubular portion is arranged to coincide with a fixed location for a mass-airflow sensor within the engine bay.

17. The method of any preceding claim, wherein the surface is generated to have a minimum separation with the one or more obstructions of 10 mm or less, preferably 5 mm or less.

18. A method of manufacturing an optimised component for an air intake system of an internal combustion engine (ICE), the method comprising:inputting the outputted computer file of claim 1 to a manufacturing system; andcontrolling the manufacturing system to form the component based on the instructions contained in the computer file.

19. The method of claim 18, wherein the step of manufacturing the component comprises:manufacturing a mould based on the generated surface stored in the computer file; andmoulding the optimised component using the manufactured mould.

20. The method of claim 19, wherein the method further comprises adjusting the generated surface to optimise release of the optimised component from the mould.

21. The method of any of claims 18 to 20, wherein the optimised component 5 comprises carbon fibre.

22. The method of any preceding claim, further comprising: manufacturing a test component based on the instructions contained in the computer file;performing one or more tests on the test component; and10 adjusting the generated surface based on the results of the tests.

23. A component for an engine air intake system manufactured using the method of any preceding claim.

24. A vehicle comprising the component of claim 23.

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