BMW G20 B58

The BMW G20 B58 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 to the engine performance as the turbo would have to build boost with heated, less dense air and so the only way to ensure IATs 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 minimize the radiative heat transfer from the exhaust manifold. In order to maximize 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.

Dual Feed Carbon Fiber Airbox

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 that 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 minimize 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 that 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 utilize 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.

Carbon Inlet Tube

The G20 B58 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.

The stock inlet tube has a flexible and convoluted section to provide movement with the engine. This however also adds the possibility of turbulence in the flow path as there are multiple faces which can cause eddies. We replace this with our carbon tube which is smooth and also has a larger internal volume. Unlike most aftermarket intakes we maximised the size of our intake tube, the OEM inlet tube has an internal diameter of 80.8mm or 3.2” at the filter end. Our tube for cars built after November 2018 has an internal diameter of 109mm or 4.3”. This equates to a massive 82% increase in cross sectional area over stock. The tube smoothly tapers down to the stock turbo inlet to ensure airflow remains as laminar as possible. The tube also has CNC machined fitting for the temperature sensor and the breather adapter.

Bespoke Cone Filter

Our cone filter is made from a non-woven mesh material which is double layered and is ISO tested to ensure that filtration is in line with OEM standards. The filter is cleanable and very stable at high temperatures with the base material being Urethane. The filter incorporates and internal flow guiding cone to help aid the airflow to converge while reducing the possibility of a stagnation point in the middle of the filter space. The filter medium has a significantly larger surface volume than the stock panel filter.

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 adapter
• Heat Shield with Gold Reflective Backing
• Laser Cut Stainless Steel Brackets
• Silicon Coupler with OEM Specification Clamps