Introduction

The Mercedes-AMG GT is already a formidable machine, delivering world-class performance straight from the factory. But for enthusiasts who crave even more power, the Hennessey Performance Engineering (HPE) HPE1000 supercharger upgrade is a proven path to hypercar-level output. This kit transforms the AMG GT’s twin-turbo V8 into a 1,000‑horsepower monster while retaining daily drivability. In this comprehensive guide, we break down the cost breakdown, installation process, real-world results, and everything you need to know before committing to this upgrade.

What is the Hennessey HPE1000 Kit?

Developed by Texas-based Hennessey Performance, the HPE1000 kit is a complete forced-induction upgrade for the Mercedes‑AMG GT (coupé, roadster, and GT C/GT S models). Rather than relying solely on larger turbos, Hennessey replaces the factory supercharger with a high-flow unit, complemented by a suite of supporting modifications. The result is a proven 1,000 horsepower and 950+ lb‑ft of torque at the crank.

Core Components of the Kit

  • High-flow supercharger – A redesigned twin-screw unit with larger rotors and higher boost capacity.
  • Upgraded intercooler – A larger air-to-water intercooler with improved core density and heat rejection.
  • High-flow injectors and fuel system – Upgraded injectors, fuel rails, and (in some cases) a higher-capacity low-pressure pump to maintain proper fuel delivery.
  • ECU calibration – A custom Hennessey tune written specifically for the hardware, adjusting boost, timing, and fuel mapping.
  • Belt drive system – A reinforced serpentine belt and pulleys to handle the increased parasitic load.
  • Intake and charge pipe upgrades – Larger-diameter pipes with smoother bends to reduce restriction.

Hennessey also offers an optional cat-back exhaust and upgraded downpipes for an additional power gain and a more aggressive exhaust note, but these are not strictly required for the 1,000‑horsepower target.

Cost Breakdown: What You’ll Pay

The total investment for the HPE1000 upgrade ranges widely depending on the AMG GT model year, labor rates, and any optional parts. Below is a detailed breakdown of typical costs.

Kit Price

  • Hennessey HPE1000 supercharger kit – $24,500–$26,000 (depending on exact version and any included fuel system upgrades).
  • Calibration fee – Included in the kit price for the initial tune, but retunes or custom dyno sessions may cost extra.

Labor and Installation

  • Standard installation at a Hennessey-authorized facility – $1,500–$3,000 (roughly 15–25 hours of labor).
  • Removal and reinstallation of stock components – May be billed separately if you are swapping back to stock.
  • Shipping – If sending your vehicle to Hennessey’s headquarters in Sealy, Texas, expect $500–$1,200 for enclosed transport.

Optional Upgrades That Add Cost

  • Hennessey cat-back exhaust – Approximately $2,500–$3,000.
  • Upgraded downpipes (catted or catless) – $1,200–$2,000.
  • Heat exchanger upgrade – Often recommended for warmer climates; $800–$1,500.
  • Clutch upgrade – For manual-transmission AMG GT models, a stronger clutch may be required; $2,000–$4,000.

Total estimated budget: Plan on $28,000–$35,000 for a complete, fully installed HPE1000 system including all necessary supporting modifications. For a turnkey package with exhaust and clutch, the figure can approach $40,000.

The Installation Process: Step by Step

Installing the HPE1000 kit is a high-level mechanical procedure best left to experienced technicians. Below is a detailed look at what happens during a typical installation at a Hennessey-authorized shop.

1. Pre-Installation Preparation

  • Verify the AMG GT’s model year and engine code (M178).
  • Perform a baseline dyno run and data log to check factory health.
  • Inspect the cooling system, fuel system, and belt drive for any wear.
  • Order any additional parts needed (gaskets, hoses, fasteners) that may not be included in the kit.

2. Engine Bay Preparation and Removal of Factory Components

  • Drain coolant and engine oil. Disconnect the battery.
  • Remove the factory air intake system, charge pipes, and intercooler.
  • Remove the stock twin-screw supercharger (the AMG GT uses a roots-type supercharger from the factory, located in the V of the engine).
  • Remove the factory fuel injectors and fuel rails.
  • Disconnect the supercharger drive belt and tensioner.

3. Installation of Hennessey HPE1000 Components

  • Install the upgraded intercooler with the larger core and new hoses.
  • Fit the new supercharger unit onto the engine, ensuring proper alignment with the dowel pins and seal surfaces.
  • Install the high-flow injectors and fuel rails; connect the upgraded fuel line (if supplied).
  • Install the new belt drive – often a longer belt to accommodate the larger supercharger pulley.
  • Reinstall the charge pipes, intake system, and any supplied heat exchanger upgrades.
  • Reattach all electrical connectors, coolant hoses, and vacuum lines.

4. ECU Tuning and Calibration

  • Replace the factory ECU tune with Hennessey’s proprietary calibration. This is usually done via OBDII flash.
  • The technician will log key parameters – boost pressure, air/fuel ratio, ignition timing, knock sensor feedback – on a dynamometer.
  • Adjust the tune for optimal power while preserving safety margins.
  • Typically 5–10+ dyno runs are performed to dial in the calibration.

5. Final Assembly and Dyno Validation

  • Reinstall any removed underbody panels and trim.
  • Fill fluids: coolant, engine oil, supercharger oil (if separate).
  • Perform a road test to check for drivability, check engine lights, and boost response.
  • Return to the dyno for final horsepower and torque figures. A properly installed HPE1000 kit should produce 980–1,020 whp on a Dynojet or Mustang dyno (depending on correction factors).

The entire process typically takes 1–2 weeks depending on the shop’s workload and parts availability.

Performance Results: What to Expect

After the HPE1000 installation, your AMG GT’s performance transforms. Here are the key metrics from real-world and Hensessey-claimed results.

0–60 MPH and Quarter‑Mile

  • 0–60 mph: 2.4–2.6 seconds (with proper traction and launch control).
  • Quarter‑mile: 9.8–10.2 seconds at 140–144 mph.

These times rival modern hypercars like the Ferrari LaFerrari and Porsche 918 Spyder.

Top Speed

  • Top speed: Electronically limited to 204 mph (stock limiter removed on request). Without the limiter, the car can exceed 215 mph given sufficient runway.

Real‑World Driving Impressions

  • Throttle response: The supercharger delivers instant, linear boost, unlike laggy big-turbo setups. From 2,000 rpm, the car pulls ferociously.
  • Mid‑range punch: The torque curve peaks near 4,000 rpm and stays above 900 lb‑ft all the way to redline.
  • Noise: The supercharger whine is prominent, and the exhaust note deepens significantly, especially with the optional cat-back.
  • Drivability: The car remains easy to drive gently thanks to the stock-like pedal mapping. Hennessey’s tune includes smooth part‑throttle behavior.

Keep in mind that the added power requires good tires – 315/30R20 or wider rear rubber is strongly recommended to put the power down.

Reliability and Maintenance Considerations

The HPE1000 kit has a solid track record when installed and maintained properly. However, with a 200% increase over stock power, certain systems require extra attention.

Thermal Management

  • The larger supercharger generates more heat. Hennessey’s intercooler upgrade helps, but a heat exchanger upgrade is advised for track use or hot climates.
  • Consider upgrading the coolant system – a higher‑capacity radiator or electric water pump.

Fuel System

  • The stock low‑pressure fuel pump can struggle on sustained high‑load runs. Many owners install a boost‑a‑pump or an inline fuel pump for safety.
  • Use 93 octane or higher. For maximum power on track days, blending ethanol (E30–E40) is popular but requires an ethanol sensor and retune.

Drivetrain

  • The AMG GT’s seven‑speed dual‑clutch transmission is robust, but repeated full‑throttle launches can lead to clutch wear. Some owners opt for aftermarket clutch packs.
  • Axles and driveshafts are generally fine up to 1,000 whp, but any sign of vibration should be checked.

Warranty

  • Hennessey offers a limited warranty on their parts (typically 2 years/24,000 miles).
  • Mercedes‑Benz’s factory warranty will be voided on any powertrain components affected by the modification. However, some states have laws protecting aftermarket parts; discuss this with your installer.

Regular maintenance intervals remain similar to stock, but expect more frequent oil changes (every 3,000–5,000 miles) and spark plug replacements (every 15,000–20,000 miles).

Alternatives to the Hennessey HPE1000 Kit

The HPE1000 is not the only route to big power on the AMG GT. Consider these alternatives before making your decision.

  • Renntech ECU & Downpipes: A mild tune with downpipes can push the stock supercharger to 700–750 hp for around $6,000 – much cheaper, but far from 1,000 hp.
  • Weistec Supercharger Upgrade: Weistec offers a 4.0L supercharger (vs stock 3.2L) that can reach 850–900 hp with supporting mods; price is similar to HPE1000.
  • Twin-Turbo Conversion: Companies like Gintani and UGR produce twin-turbo systems for the AMG GT that can exceed 1,500 hp, but these are far more expensive ($40k+) and require extensive fabrication.

For most owners seeking a proven, reliable 1,000‑hp package that fits under the stock hood, the HPE1000 remains the benchmark.

Conclusion

Installing a Hennessey HPE1000 supercharger kit on your AMG GT is a major performance investment – financially and mechanically. When executed by a qualified shop, the results are extraordinary: sub‑10‑second quarter‑miles, a ferocious supercharger soundtrack, and the ability to humble six‑figure hypercars. The costs range from $28,000 to $35,000 installed, but the transformation is profound. Before proceeding, ensure you have a clear plan for maintenance, fuel quality, and tire upgrades. If you want the ultimate street‑going AMG GT that retains everyday civility, the HPE1000 kit is one of the best options available.

For more details, visit the official Hennessey Performance website or check out owner experiences on the MBWorld AMG GT forum for real‑world feedback.