Step 1:  UK and some EU spec M140is have a blank which stops the low-pressure zone that builds up in front of the radiator from entering the inlet tract. Forge created FMINLD2, a carbon fibre sculped duct to replace the blank, and route more air into the tract towards the airbox.

Step 2: Now that this greater quantity of air has entered the airbox, we need a greater surface area of filtration to maximise the airflow towards the engine. Therefore, Forge decided on a high-flow performance cone filter and used their development of other upper airbox induction kits to inform the design process to create FMINDK50.

Step 3: The weak link was now the OEM inlet hose with its sound resonator and accordion ribs which cause turbulence and slows down the airflow. They created FMINLH25 (included with this kit) from a multi-ply smooth silicone to significantly reduce turbulent airflow, and to handle big boost builds. Forge also increased its diameter from 85mm to 90mm.

Forge used SolidWorks CAD, 3D prints and numerous dyno sessions to truly unlock the power. Simulation testing played a large part in the design process to help maximise the airflow.

They were able to experiment with the airflow entering the chamber from the inlet tract into the lower airbox, by changing the position of the filter, the size and location of the louvres and other variables to ensure that the intake is maximising performance.

The 3D printed prototypes helped with comparing simulation testing to real world driving conditions.. This is a valuable comparison that is used in the top tiers of motorsport, now being brought to your vehicle.

Using carbon fibre brings obvious benefits of strength, lightweight and aesthetics. However, a part that is often forgotten is its low thermal conductivity, which means it reduces heat soak and transmission of said heat to nearby items. Keeping Inlet Air Temps (IAT’s) low is often a difficult part of developing induction systems, so replacing metal or plastic inlet solutions for FMINDK50 will help decrease IAT’s and increase the volume of air supplied to your vehicles engine that is compressed by the turbo charger.

This has a better effect on performance when cool as this is to provide the engine with more oxygen (denser air), thus improving the combustion in each cylinder. In addition, by regulating and reducing the air temperature, it also increases the reliability of an engine by keeping the AFRs (Air Fuel Ratios) in each cylinder at a safe level, which in turn, can increase an engines power due to the air being cooler. A bigger bang is then created within the cylinder, providing the correct amount of fuel is added. This can equate to an increase in BHP and torque.

The results above speak for themselves. With the added benefit of being a very easy component to fit with no specialist tools this is a superb, affordable modification for the BMW enthusiast.

From the Dyno Graph shown above, performance gains can be expected from 2500RPM to the red line with 11BHP and around 19NM of torque at peak RPM. The torque increase is clearly visible on the dyno graph and is clear when driving the car. As soon as it comes onto boost you can feel that hit of extra torque pushing you all the way to the redline. The M140i tested on the dyno was stock other than a Pipercross performance panel filter, but with a tuned vehicle you will see greater percentage gains as the vehicle will be able to utilise the increase in volume of cold air.