With the reduction of Engine Displacements, automotive manufacturers are trying to stretch fuel economy and reduce CO2 emissions without giving up horsepower and low end torque. Active intake manifolds and air intake systems are taking on a much bigger roll helping to achieve these targets. Currently taking on more and more challenges to increase low end torque while still reducing the effects of greenhouse gases, MANN+HUMMEL is right at the forefront when it comes to developing solutions that meet these specifications. We have developed a family of active air intake systems for different requirements.

Developments in engine technology are being regulated by the Euro 6.2 and 7 exhaust emissions standards, which are due to be implemented in the near future. With smaller displacement engines, more torque at low engine speeds and the provisions of the all-important ‘Real Driving Emissions’ (RDE) legislation, which aims to reduce actual emissions in day-to-day driving, are right at the top of the list of requirements.

Here at MANN+HUMMEL we have designed some fascinating air intake systems that will meet these requirements and allow us to improve combustion process in engines. We have adopted a holistic approach, so where the focus was previously on the individual components within air intake systems, we are now looking at the system as a whole, from the turbocharger to the cylinder head and the interaction between the charge air line and the intake system. Using resonance charging alone or together with runner length switching, we find ourselves in a position to offer our customers real benefits.

Let’s take the example of the starting torque, which is still an important requirement, despite the best efforts of car manufacturers to pursue downsizing. Engines that are getting smaller yet increasingly more powerful go hand in hand with a lower starting torque. This is where our active air intake systems come in, increasing the torque at low speeds. To clarify, we are talking about an increase of 10–30% at speeds of between 1000 and 1700 rpm.

We have several solutions ready to go, which vary in their complexity and address different requirements:

  • The most straightforward solution is a standard charge air duct that has been fine-tuned in terms of diameter and length.
  • The next step up is an active charge air duct, which can be switched between a short and a long charge air line (ACAD 1.0. ‘active charge air duct’).
  • The next version up – ACAD 2.0 – sees extra volume added to the charge air duct to enhance performance.
  • The double resonance system (DRS) goes one step further, featuring two switchable ducts and two switchable volumes, enabling a torque increase of up to 30%. Both the ACAD and DRS systems apply the principle of resonance charging.
  • At the very top of the range, offering maximum performance but also being the most complex option, is our active intake module with an integrated charge air cooling system. This is fitted with an eBOOSTER from BorgWarner, which blows more air into the combustion chamber. As the eBOOSTER requires additional electrical energy, it is more expensive than resonance charging. However, it is also a lot more powerful and functions independently thanks to its integrated indirect charge air cooling system. This module also comes equipped with Charge Motion Control Valves, which create turbulence in the combustion chamber, thereby improving combustion at lower speeds. We will be exhibiting a prototype of this solution at the IAA.

Our world has changed completely since I started my job as a product champion for intake manifolds five years ago. With the increasing availability of turbo engines, it was conventional wisdom that auxiliary functions were not necessary any longer and manifolds became simpler. They were nothing more than two shells I have to say that I am quite proud that we did not continue down this path. Instead, we realised that, with our strengths as a system provider residing in areas such as functional integration and active intake systems, it was important for us to retain an overview of the air intake system as a whole if we were to be in a position to make a positive contribution to the global goal of reducing CO2 emissions.

It is exciting to see that the latest developments on the market have proven us right, especially with the demand for active intake systems steadily increasing. This helps us provide tangible results for our customers and bring value back to the intake manifold, giving us of an edge over our competition. We have focused on the right issues and we have developed the right solutions – now it is just a matter of rolling up our sleeves and producing production assemblies to meet our customers growing needs.