Exhaust & Induction
Exhaust & Induction
Improving how your car breathes on the track
The two mainstays of performance modifications – exhaust and intake systems are the key starting points when it comes to unleashing extra power from your car’s engine. Boasting not only performance gains but also enhancing your vehicle’s soundtrack not only will these upgrades boost your horsepower, they’ll widen the smile on your face too!
Air Filters & Induction Kits
Oxygen is a vital part of combustion and optimising your engine’s intake system will ensure that the engine has all the cold air it can consume, keep it functioning efficiently and generating the most power possible. One of the simplest performance upgrades is to replace the original paper filter element with a free-flowing performance air filter, normally made from oiled cotton or foam and completely serviceable. A performance filter element drops right into your original air box and has much better flow than the original paper element meaning your car’s factory air box will perform as well as it possibly can.
For the best possible upgrade, it’s necessary to escape the limitations of the standard intake system – depending on make and model of car induction kits are available in all shapes and sizes, moving away from the original air box allows a much bigger air filter to be utilised. With an induction kit a far larger cone shaped filter can be used giving a significantly increased surface area over a flat panel, it also gives the opportunity to implement a stub-stack style trumpet at the filter neck increasing the velocity of passing air. For best performance a closed intake system will ensure the best supply of cold air into the engine whereas an open system will be the better sounding kit. Some kits will replace pipework between the airbox and engine, this will further enhance performance and noise benefits and also provide the opportunity to increase the diameter for the intake system allowing a greater mass of air to pass through.
Our recommend brands for air filters & induction kits
Exhaust Systems
Improving the flow of air out of the engine is arguably even more important than upgrading the intake system and this is where the right choice of exhaust system is critical! Once again there are benefits both in performance and in sound, typically a factory exhaust system will be limited by its smaller diameter, tighter bends and restrictive silencers, it will also be designed to be quiet at cruising speeds meaning more of said silencers. An additional benefit of moving away from the standard exhaust is that the majority of aftermarket performance exhausts will be of a stainless-steel construction meaning no corrosion issues unlike the majority of factory, mild-steel systems.
Performance exhaust systems feature a number of variables: diameter, material, number of silencers and tail-pipe design. Naturally a larger diameter pipe will be able to flow a greater amount of air away from the engine resulting in increased performance and also more volume. There are a range of materials used for aftermarket systems – some are available in mild-steel keeping manufacturing costs lower, moving on from this there is stainless steel which won’t rust commonly resulting in lifetime warranty. Beyond this there is also the premium option of titanium which is considerably lighter in weight and due to its thin wall construction has unique sound qualities. The number of silencers will help to regulate the overall volume of the system under acceleration which is a particularly important consideration when it comes to track use and the imposed noise restrictions. Lastly tailpipe design, differing tail pipe design offers both style choice, sometimes including the use of carbon fibre, and fine tuning of the exhaust note.
Our recommend brands for exhaust upgrades
Intercoolers
Many modern performance engines are supercharged or turbocharged, otherwise known as forced induction. These terms refer to a system where intake air is compressed before it is forced into the engine under pressure, filling the cylinder with as much oxygen as possible and boosting horsepower. The drawback of these systems is that with compression comes heat and hot air meaning reduced performance. To combat this issue most, if not all forced induction systems will feature a cooler – an air-to-air intercooler or a water-to-air charge-cooler both of which can be upgraded.
Performance coolers are of an improved design offering enhanced capacity and increased efficiency. Vehicle specific solutions will make use of available space to implement a larger size, more efficient cooler reducing intake temperatures as much as possible. Some intercooler applications will offer relocation to a more effective position, typically forward facing just behind the front bumper, directly in the path of oncoming cold air. For charge-cooled systems it’s also possible to upgrade forward facing components, the radiators responsible for cooling the ‘water’ part of the network can often be improved resulting in a lower more stable temperature for more efficient heat exchange.
Aftermarket intercoolers also feature a more reliable construction, typically they will be a fully fabricated component meaning no plastic end tanks that can become separated from standard cores under increased boost found encountered with tuned cars. Upgraded coolers installed independently boast more consistent and reliable performance where standard parts would typically be overwhelmed by the extremes of track driving. They can also be installed as part of a package of supporting modifications ahead of engine tuning where reduced intake temperatures allow boost pressure to be further increased.
Our recommend brands for intercooler upgrades
Downpipes & Manifolds
The front-most section of the exhaust system is typically where the restrictions will start, be it a factory down pipe with catalytic converter or an inefficient cast manifold or combined ‘mani-cat’ (combined manifold and cat), any performance loss here will be felt by the rest of the exhaust system – upgraded or not! In order to get the most out of any exhaust upgrade it is imperative to upgrade the connection to the engine too. Replacement of the exhaust manifold on a naturally aspirated engine has huge potential in terms of power gains which can be hard to come by without forced induction.
Both downpipes and manifolds can provide the opportunity to remove the catalytic converter completely and whilst this is the best option in terms of performance it does mean your car is no longer road legal! Sports cats are an alternative option allowing you to remove the restrictive factory cat whilst remaining on the right side of your MOT tester.
Our recommend brands for downpipes
Sports Cats
As far as performance is concerned catalytic convertors are a necessary evil, both for road and more recently circuit/competition use. Factory catalytic converters typically result in some restriction within the exhaust system as a result of being designed to work with the smaller standard diameter, creating a restriction after the converter also helps to generate and retain a higher temperature within the catalyst itself maintaining a much greater efficiency. Sports catalytic converters offer the same emissions reduction properties but with reduced restriction and the ability to be matched to the larger system diameter of a performance exhaust. Often sports cats will be offered as a part direct replacement for the factory down pipe or manifold as they are best situated close to the engine to absorb as much heat as possible for the greatest amount of efficiency.
Our recommend brands for sports cats
