Unlocking the Full Potential of the BMW S38: Tilton Multi-Plate Clutch + VAC Lightweight Flywheel

BMW’s S38 engine has never been shy about announcing itself. Big displacement, mechanical personality, and the unmistakable howl that defined the E28 M5 and E34 M5. When tuned and built correctly, the S38 becomes something rare in the modern era: a naturally aspirated straight-six that rewards every intentional ounce of engineering you throw at it.

One of the greatest performance gains you can unlock in an S38 build doesn’t come from the cylinder head, throttle bodies, or compression—it comes from reducing rotating mass and upgrading the drivetrain to handle real power. That’s where the Tilton multi-plate clutch paired with a VAC Motorsports lightweight billet flywheel becomes a revelation.

This combo doesn’t just sharpen the engine’s character. It transforms the entire car.

Why This Setup Works So Well on the S38

The S38 responds dramatically to changes in rotating mass. A lighter, stronger flywheel paired with a motorsports-grade clutch lets the engine rev as it should—free, immediate, eager, and unburdened.

What makes this particular pairing powerful is that each component solves a core limitation in the factory system:

Tilton Multi-Plate Clutch (BMW S38 Fitment)
Tilton engineered this system to handle serious torque and rapid shifts without chatter or failure. Ideal for builds exceeding the limits of stock components.

Benefits include:
• Exceptional torque capacity for high-hp S38 builds
• Smooth engagement with race-proven durability
• Compact, lightweight design reduces rotational inertia
• Superior heat management for track and endurance use

VAC Motorsports Lightweight Billet Flywheel
Designed in-house and CNC-machined from premium materials, this flywheel brings the S38 to life.

Performance advantages:
• Faster revving and quicker throttle response
• Significant reduction in rotating mass
• Stronger, safer, and more stable at high RPM
• Optimized for Tilton clutch fitment
• Perfect for E28 M5, E34 M5, and custom swap builds

Pair these together and the result is unmistakable: the S38 feels sharper, more responsive, and vastly more eager to make power.

Installation, Fitment, and What to Expect

Because the S38 platform has real estate variation between generations, understanding the correct fitment is crucial. The Tilton + VAC flywheel package is designed specifically for:

• E28 M5
• E34 M5
• S38 swap cars (E30, E36, E46, and custom motorsport builds)

During installation, you’ll notice:
• The Tilton stack height aligns cleanly with VAC’s flywheel geometry
• Pedal feel becomes firmer but far more consistent
• Engagement is predictable even under aggressive driving
• Throttle blips become razor-fast—ideal for heel-toe driving

Engine builders push this setup because it’s predictable, tested, and stable at high RPM—exactly what the S38 demands.

Real-World Performance: Dyno & Driving Impressions

The star of this setup is responsiveness. On the dyno, you’ll see the S38 climb through its powerband faster, with less drivetrain drag and smoother torque delivery. On the street or track, the difference is immediate:

• The engine spins up with noticeably less effort
• Rev-matching becomes telepathic
• Acceleration feels more alive, especially in the midrange
• Drivetrain durability increases with better heat control
• Losses through the drivetrain are reduced

For racers chasing lap times, this is a no-brainer. For street-legal builds, it’s one of the most satisfying upgrades you can make.

Ready to Upgrade Your S38?

VAC Motorsports has supplied parts and engineering solutions for S38 engines for decades. If your M5 is due for a clutch, getting a lighter, stronger, race-proven system puts you ahead of the curve.

Order or request tech support:
📧 Sales@VACMotorsports.com