Why Upgrade to a Single Turbo on the S55?
The BMW M4’s S55 engine is already a strong platform—but the factory twin turbos have limitations when it comes to high horsepower builds.
For enthusiasts chasing serious power, the move to a single turbo setup is one of the biggest upgrades you can make.
At higher levels, stock turbos struggle with:
- Airflow limitations
- Heat efficiency
- Power consistency at higher boost
A properly built single turbo setup solves all of that.
What Is a 4N Motorsport Single Turbo Kit?
The 4N Motorsport single turbo kit is designed to replace the factory twin turbo system with a larger, more efficient single turbocharger.
This allows the engine to:
- Move significantly more air
- Support higher boost levels
- Produce much higher horsepower
It’s one of the most effective ways to transform the S55 into a true high-performance build.
Why Enthusiasts Choose a Single Turbo Setup
Switching to a single turbo isn’t just about peak numbers—it changes the entire driving experience.
Key Benefits:
- Massive horsepower potential (600–800+ HP builds)
- Strong top-end power
- Cleaner, more efficient turbo system
- Simplified turbo configuration
For serious builds, a single turbo setup offers scalability and performance that stock twins can’t match.
Supporting Mods Required (Critical for This Build)
A single turbo upgrade is not a standalone mod—it requires a full supporting setup.
Required Upgrades:
- Fuel system upgrades (port injection recommended)
- Upgraded intercooler for heat management
- Performance exhaust system
- Intake system upgrades
- Custom ECU tuning
Without these, the setup won’t perform safely or efficiently.
The Installation Process (Overview)
Installing a single turbo kit on the S55 is a complex process that requires experience and precision.
Key Steps:
- Remove factory twin turbo system
- Install bottom-mount single turbo manifold
- Mount turbocharger and wastegate
- Install oil and coolant lines
- Fit downpipe and exhaust connections
- Install intake and charge piping
- Integrate fueling system (if applicable)
- Perform custom tuning
This is not a simple bolt-on—it’s a full transformation of the turbo system.
Performance Gains: What to Expect
A properly installed and tuned 4N Motorsport single turbo setup can deliver:
- 600–800+ horsepower potential
- Strong top-end acceleration
- Increased boost capability
- More consistent power delivery
The biggest difference?
👉 The car keeps pulling hard at higher RPMs where stock turbos fall off.
Driving Feel: Twin Turbo vs Single Turbo
Switching to a single turbo changes how the car feels:
Twin Turbo (Stock Feel):
- Faster spool
- Smooth low-end power
Single Turbo (Upgraded):
- Slightly later spool
- Much stronger top-end power
- More aggressive power curve
For performance enthusiasts, the trade-off is worth it.
Why Tuning Is Everything
A single turbo build is only as good as the tune behind it.
Proper tuning ensures:
- Safe boost levels
- Correct fueling
- Smooth drivability
- Engine reliability
This is where builds are made—or broken.
Real-World Applications
The 4N Motorsport single turbo kit is ideal for:
- High horsepower street builds
- Roll racing setups
- Track-focused performance cars
- Fully built S55 platforms
It’s designed for enthusiasts who want more than just bolt-ons.
Final Thoughts
The BMW M4 S55 is an incredible platform—but a single turbo setup takes it to a completely different level.
With the 4N Motorsport single turbo kit, you’re not just upgrading your car—you’re building something that delivers:
- Serious power
- Real performance
- A completely new driving experience
For those chasing big numbers and real results, this is one of the most powerful upgrades you can make.