Skip to product information
1 of 1

benzunited parts

Stage 2 Billet Turbo Upgrade for Mercedes-AMG GT / GT S / GT C / GT R (R190) – M178 4.0L BiTurbo

Stage 2 Billet Turbo Upgrade for Mercedes-AMG GT / GT S / GT C / GT R (R190) – M178 4.0L BiTurbo

Regular price $4,995.00 USD
Regular price Sale price $4,995.00 USD
Sale Sold out
Shipping calculated at checkout.

Stage 2 Billet Turbo Upgrade — Mercedes-AMG GT (R190)

The Stage 2 Billet Turbo Upgrade is the largest factory-housing turbo upgrade available for the M178 4.0L V8 BiTurbo — engineered for serious power while keeping true bolt-on fitment in the AMG GT.

Built for high-boost street cars, track builds and setups planning for more power later, the Stage 2 turbo dramatically increases airflow through custom billet internals while retaining OEM-style installation.


Vehicle Fitment

  • Mercedes-AMG GT (R190) — M178 4.0L V8 BiTurbo
  • Mercedes-AMG GT S (R190) — M178 4.0L V8 BiTurbo
  • Mercedes-AMG GT C (R190) — M178 4.0L V8 BiTurbo
  • Mercedes-AMG GT R (R190) — M178 4.0L V8 BiTurbo

Not sure your car is covered? Send us your VIN and we will confirm before you order.


What Makes the Stage 2 Turbo Different

Built around the largest turbo configuration that still fits inside the factory housing footprint — massive airflow capability without the complexity or fitment problems of a full custom turbo system.

  • Largest factory-housing turbo available for the platform
  • Billet compressor wheel — 55mm inducer / 73mm exducer
  • High-flow turbine wheel — 55mm
  • Fully bolt-on installation

Technical Specifications

Stage 2: compressor 55mm inducer / 73mm exducer · turbine 55mm

Factory turbo, for reference: compressor 41.7mm inducer / 56mm exducer · turbine 44.5mm / 50mm · A/R 0.57

The size difference shows how much additional airflow capacity this upgrade provides over stock.


What These Turbos Need

The turbo will physically install on a stock car. It will not make its numbers on one.

Custom ECU calibration — required. The factory file cannot run these turbos.

Core Return & Wastegate Instructions

  • Core return required
  • Remove your factory wastegate actuators before shipping your cores
  • If turbos are received with wastegates installed, do not use them — reuse your original factory wastegates for known calibration and reliability

Who This Turbo Is For

  • Owners targeting 850–1000+ HP
  • Track-focused or high-boost street builds
  • Future-proof setups planning for more power later

Need help confirming fitment or supporting mods? Contact us before ordering and we will help you build the setup correctly the first time.

View full details