Description

The BMW G20 B48 Eventuri intake has been developed to provide the turbo with a less restrictive flow path whilst maintaining low inlet temperatures. Heat and Volume are the main considerations when designing an intake for turbocharged engines. In the G20, the intake system is located next to the exhaust manifold which rapidly heat soaks the engine bay. High temperatures are detrimental for engine performance as the turbo would have to build boost with heated, less dense air and so the only way to ensure IAT’s are kept to a minimum is for a fully sealed intake. This however, results in a restriction with only one stock air feed to draw air in from. During development we noticed an additional opening into the wheel arch area and took advantage of this by adding a secondary feed to our airbox. Furthermore our sealed airbox also has a heat shield with gold reflective to minimise the radiative heat transfer from the exhaust manifold. In order to maximise volume we made the airbox as large as possible with a recess for potential strut braces. The stock convoluted intake tube is replaced with a smooth carbon tube which is also larger in internal volume with a starting internal diameter of 111mm (4.4″) smoothly tapering down to match the turbo inlet. The tube provides a smooth path from the filter to the turbo inlet. Finally we use a custom made high-flow dry filter which is ISO tested for filtration performance and has a larger filtration area than the stock filter.

The Eventuri G20 B48 intake system consists of a number of components engineered to perform a specific purpose and fabricated to the highest of standards. We use 100% pre-preg carbon fiber with no fibreglass which means we can achieve a smooth internal surface to maintain smoother airflow. Here are the details for each component and the design ethos behind them:

Each intake system consists of:

• Carbon Fiber Airbox with Dual Feeds
• Bespoke High Flow Dry Cone Filter
• Carbon Fiber Inlet Tube
• CNC Machined Temperature Sensor Mount
• CNC Machined Breather adapters
• Heat Shield with Gold Reflective Backing
• Laser Cut Stainless Steel Brackets
• Silicon Reducer with OEM Specification Clamps

Crafted from Prepreg Carbon Fiber, the airbox serves 2 objectives – to seal the filter against engine bay heat and to provide a dual cold air feed. Since the airbox is positioned next to the exhaust manifold it is crucial for the filter to be fully sealed so we designed the airbox to encapsulate the filter and at the same time provide a large internal volume. To seal the intake tube we have designed a laser cut plate with a rubber sealing strip which secures to the airbox. The intake tube passes through the plate and the rubber seal ensures heated air does not enter the airbox. To further minimise heat soak, there is an additional heat shield with a gold reflective layer on the exhaust manifold side which effectively combats the radiant heat transfer.

Having a fully sealed airbox results in the problem of having a restriction for the cold air feed. The stock airbox draws air from a single duct which extends to the front bumper area. During development we identified another area to draw cold air from which was a gap between the wheel arch and the chassis on which the airbox sits. To utilise this feed we extended a scoop at the back of our design which protrudes into the wheel arch and can even be seen after installation behind the front wheel. This second feed allows the turbo to draw from a larger area therefore reducing the restriction.

The G20 B48 OEM airbox system was updated in cars built after November 2018 where the airflow sensor was replaced with a temperature sensor in the inlet tube. Prior to this date, all airbox systems had an airflow sensor and for this reason we offer 2 variations. The V1 intake which has an inlet tube to take the MAF (airflow) sensor and the V2 intake for cars built after November 2018 which use a temperature sensor. The difference in the tubes can be see below.