15 Dec How to Build a Mercedes E55 AMG Custom Air Intake
The FMU Megaphone – our secret weapon is available for purchase HERE
Automotive manufacturers invest heavily in research and development when it comes to air intake design, but what happens when you want to improve airflow beyond stock without an engineering degree? For this build, we took a Mercedes E55 AMG wagon—already upgraded with a massive 2.9L Whipple supercharger, dual fuel pumps, and oversized injectors—and focused on creating a custom air intake setup to feed the engine properly while maximizing power and efficiency.
Understanding Airflow and Intake Restrictions
Before our work, the car was producing restricted power due to the factory intake setup. The stock intake was adequate for the original supercharger, but the 2.9L Whipple and 90mm throttle body needed more air. Completely removing the intake during dyno testing showed immediate gains, confirming that airflow was the limiting factor.
Cold, dense air is critical for engine performance. The more efficiently you can supply it, the more power the engine can make safely. But designing an intake system isn’t just about cramming in as much air as possible—sensor placement, space constraints, and airflow dynamics all play a role.
Design Considerations and Challenges
When designing our intake system, we had to consider:
- Factory sensor placements, such as crankcase ventilation and mass airflow sensors.
- Piping diameter to ensure correct airflow calculations and avoid triggering engine errors.
- Material selection: stainless steel, aluminum, and thermoplastics each have pros and cons regarding heat conductivity, durability, and weight.
- Space constraints in the engine bay, especially between the throttle body and firewall.
- Filtering to protect the engine from debris without restricting airflow.
We also drew inspiration from past FMU projects, like carbon airboxes for the Audi C5 RS6 and velocity stacks for BMWs, focusing on designs that enhance airflow and sound while remaining safe for the engine.
Calculating Optimal Intake Size
While we aren’t formally trained engineers, we used a practical approach to calculate pipe diameter. For a stock E55 AMG M113K engine:
- Displacement: 332 cubic inches
- Peak RPM: 6,500
- Volumetric efficiency: ~118%
Using a simplified formula for optimal airflow, we determined a single intake pipe should be around 5.49 inches in diameter. Since the E55 has dual intakes, this translated to ~3.88 inches per pipe. Realistically, due to space limitations and the 92mm Hellcat throttle body, we could only fit ~3.5-inch piping on each side, requiring a dual intake setup.
Material Choice: Aluminum Over Steel
Aluminum was chosen for its balance of heat conductivity, weight, and ease of fabrication. While steel is durable, it’s prone to corrosion and heat retention, and stainless steel, though resistant, is heavier and absorbs heat quickly. Aluminum allows for a reliable, repeatable design that can be fabricated in-house.
Designing a Practical Intake Manifold
Space constraints required creative solutions. We initially considered a boxy manifold, but it proved too complex to reproduce consistently. Our in-house CAD and 3D printing expert, Oliver, helped simplify the design into a 4-inch section connecting to the 3.5-inch intake pipes, allowing for proper airflow and easier fabrication.
Filters and Final Testing
Choosing the right filter was critical. The system needed enough airflow for our supercharged setup without restriction. We selected Volant Power Core filters that provided the necessary volume and fit within the engine bay. Dyno testing confirmed that our filtered setup achieved power numbers close to running without air filters, validating the design.
Key Takeaways
The biggest challenge when designing a custom intake is space constraints. Maximizing airflow without interfering with sensors is key. Testing is the only way to confirm effectiveness, and practical automotive experience often outweighs theoretical calculations.
While engineering formulas and optimal calculations provide guidance, real-world solutions depend on creativity, fabrication skill, and understanding the car’s limitations. With our dual 3.5-inch pipe setup, proper filtration, and a simplified aluminum manifold, we achieved a balance of airflow, engine protection, and manufacturability.
Stay tuned for the next episode when we finish dyno tuning this E55 AMG and finalize the intake system with cosmetic touches for the engine bay.
Foreign | Domestic | Performance
To book an appointment or find out more information, hit up our website or email/call:
– www.fluidmotorunion.com
– (630) 305 3054
– [email protected]
– Facebook.com/FMU
No Comments