ARM S58 Intake IAT Testing

Introduction

Intake air temperatures are crucial to engine performance. Colder air is more dense, allowing more air and fuel to fill the combustion chambers, resulting in higher power levels. 

Enter the S58 engine: a powerhouse in BMW's latest line-up of turbocharged engines. While the engineers designed this engine superbly, the intake system has room for improvement.

The stock intake system on the S58, a 3.0L twin-turbo straight-six, has each turbo with its own dedicated intake. These intakes are positioned on either side of the engine bay and draw air from the front grille through closed boxes. However, despite the G8X's large front grille, the air flow to the filter boxes and turbos is not optimal.

ARM  MOTORSPORTS and the Pursuit of Performance

As a leader in value performance products, ARM provides expert solutions now for the S58 platform. The ARM S58 Intake relocates both filters to one side, significantly shortening the intake length. This reduces the distance the air needs to travel to the turbo, enhancing throttle response, minimizing turbo lag, and reducing any change in temperature from ambient heat.

Our setup uses open cone filters with an inverted conical design that promotes increased air speed and flow. Positioning these filters strategically allows them to intake the freshest, coldest air possible.  But do open filters in the engine bay increase IAT's?  

NUMBERS DON'T LIE

The results of our S58 Intake testing speak for themselves:

In the graph below, the yellow line represents the stock intake IATs, the blue line is the ambient air temperature (our control), and the grey line shows engine RPM. The red line indicates the IATs with the ARM intake.

The data clearly shows that the ARM intake consistently maintains lower IATs compared to the stock intake, even occasionally falling below the ambient temperature.

Additionally, a bar graph below the line graph illustrates the delta between the Stock and ARM IATs, further highlighting the performance improvement.

Conclusion