MERCEDES A35 AMG / A250 - Eventuri

*Some photos show optional Carbon Turbo Tube.
Fitment: Mercedes A35 AMG, CLA35 AMG, A250, CLA250
Performance Increase : 15-20hp, 15-18ft-lb

The Mercedes A35 AMG Eventuri intake has been developed to provide the turbo with a less restrictive flow path whilst maintaining low inlet temperatures. Reducing heat soak and increasing internal volume are the main considerations when designing an intake for turbocharged engines. In the A35, the intake system is in close proximity 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. In order to reduce the restriction from a sealed intake we have increased the volume of the airbox by relocating the ECU and also allowing an opening in the airbox on the cold side which is away from the direct heat of the manifold. The carbon inlet tube is larger in internal volume with a starting internal diameter of 111mm (4.4″) smoothly tapering down to match the turbo inlet pipe. 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 A35 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
• Bespoke High Flow Dry Cone Filter
• Carbon Fiber Inlet Tube
• CNC Machined Inlet Flange
• Laser Cut Stainless Steel Brackets and ECU Cover
• Silicon Coupler with OEM Specification Clamps

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 sealed so we designed the airbox to encapsulate the filter and at the same time provide a large internal volume. The intake tube passes through a rubber seal in the airbox which ensures heated air does not enter. By relocating the ECU, we have been able to increase the height of the airbox to maximise volume and therefore allows us to use a larger filter.

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 through a rubber section which also has multiple ridges. Our design eliminates this rubber section and therefore provides a smoother cold air entry path. Furthermore to derestrict the intake, we have added a cutout on the cold side of the airbox near the bonnet shut which allows the filter to draw additional air.

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 an 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.

Dyno Testing

Dyno testing was carried out by MSL Performance who are a Mercedes specialist based in the UK. A fully standard A35 AMG was tested with the stock airbox and then with the Eventuri intake back to back whilst ensuring external conditions were the same. As can be seen below the intake provides a gain in performance throughout the RPM range. The highlighted point shows a significant gain of power where the intake allows a higher flow rate to be maintained in the higher RPM range where the stock airbox starts to become a restriction. The resulting gains are noticeable on the road with better throttle response and improved acceleration times. With a tuned A35 we would expect even better gains as the demand from the turbo increases.