M112 Supercharger Service — Porting, Rebuild & Snout Bearing for Ford and Mercedes
FAS Motorsports ports, rebuilds, and performs snout bearing service on Eaton M112 superchargers for Ford and Mercedes-Benz AMG applications. We receive units nationwide from our facility in Punta Gorda, FL.
Vehicle Applications
Ford:
- 2003–2004 Ford Mustang SVT Cobra (4.6L 4V) — 390 crank hp stock
- 1999–2004 Ford SVT Lightning (5.4L) — 380 crank hp stock
- 2003 Ford Thunderbird (supercharged variant)
Mercedes-Benz AMG:
- C32 AMG (2001–2004) — 349 crank hp stock
- E55 AMG (2003–2006) — 469 crank hp stock
- SL55 AMG (2003–2006) — 493 crank hp stock
- CLK55 AMG and other M113 AMG applications
Note: Ford and Mercedes units share the M112 designation but differ in inlet configuration, rotor geometry, and port dimensions. Porting scope is application-specific.
Supercharger Specifications
- Type: Roots-type positive-displacement
- Displacement: 112 cubic inches / approximately 1.8 liters
- Rotor lobes: Twin-lobe (3+3 configuration)
- Factory boost (SVT Cobra): ~8 psi
Services
- Snout porting — inlet throat opening, casting flash removal, transition smoothing. On Cobra and Lightning, the factory casting restriction is significant — porting is one of the highest power-per-dollar mods available on these platforms.
- Full inlet porting — snout plus discharge port. Recommended before pulley reduction.
- Snout bearing replacement — most common standalone service; resolves RPM-tracking whine and prevents cascading seal failure.
- Coupler replacement — the rubber coupler between the rotor pack drive shaft and snout nose drive. Worn couplers produce a lag or slap at boost onset.
- Front seal replacement — paired with bearing service.
- Full rebuild — complete teardown, rotor inspection and clearance check, bearing/coupler/seal replacement, port work, reassembly to spec, rotation verification before shipping.
Common Failure Points
Snout bearing failure — the front bearing assembly takes heat cycling, oil starvation stress, and belt tension load. Symptom: whine that tracks with engine RPM — not belt speed — worsening under boost.
Coupler wear — the rubber coupler between the rotor pack and snout nose drive deteriorates with heat and age. Symptom: hesitation or slap at boost onset.
Inlet restriction — factory casting marks limit airflow on modified engines making more power than the factory calibration expected. Porting addresses this directly.
SVT Cobra Build Path
The standard mod path for the 2003–2004 Mustang SVT Cobra — snout port, pulley reduction, tune — routinely delivers 450–500+ whp on pump gas with stock supporting hardware. The factory M112 casting restriction is among the most significant airflow limitations on these cars. Porting before a pulley change is the correct order of operations.
The SVT Lightning uses a different inlet configuration. Contact us before shipping to confirm porting scope for your application.
How to Send Your Unit
Remove the supercharger and ship to FAS Motorsports in Punta Gorda, FL. We inspect on arrival and contact you before proceeding. Pricing and turnaround time are confirmed at intake.
Contact us to arrange service.
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