The Full Price of Power: Upgrading Your AMG GT to 700 HP with EKLIPSE Parts

The Mercedes-AMG GT is already a formidable machine, blending handcrafted luxury with track-bred performance. Stock figures ranging from 469 to 577 horsepower are exhilarating, but for a growing number of enthusiasts, that’s just the starting point. Tapping into the full potential of the AMG GT’s M178 engine often means aiming for the 700-horsepower mark, a threshold that transforms a grand tourer into a genuine supercar slayer. EKLIPSE has emerged as a go-to name for this kind of upgrade, offering precision-engineered components designed specifically for AMG powertrains. This guide breaks down the real costs of that 700 HP build, from parts and labor to the hidden expenses that can catch owners off guard. Whether you are planning a weekend project or a shop-built beast, this cost breakdown will help you budget realistically.

Understanding the AMG GT’s Foundations

Before diving into the parts list, it is worth understanding exactly what you are working with. The AMG GT lineup, including the GT, GT S, GT C, and GT R, all share the same basic 4.0-liter twin-turbo V8, but with varying levels of factory boost, cooling, and internal calibration. The base AMG GT (GT 43/53 are not included here as they use a straight-six) produces around 469 HP, while the range-topping GT Black Series pushes nearly 720 HP from the factory with extensive engine modifications.

For a standard AMG GT or GT S aiming for 700 HP, you are essentially bridging the gap between stock and the Black Series or aftermarket extreme builds. The M178 engine is robust, with a closed-deck block and forged internals in many versions, but it has limits. Pushing to 700 wheel horsepower—often closer to 800 at the crank—requires careful selection of supporting upgrades. EKLIPSE specializes in this medium, offering components that work without requiring a full engine rebuild, but they demand high-quality fuel and diligent maintenance.

Key Components for the 700 HP Upgrade

Every 700 HP build follows a similar formula, but the specific parts and their costs vary widely. Below is the essential list of performance parts needed to safely and reliably reach this power level with EKLIPSE components. Note that some items are optional but strongly recommended for longevity.

Turbocharger Upgrade

The stock turbochargers on the AMG GT are effective up to about 580-600 HP, but beyond that, they become a bottleneck. EKLIPSE offers upgraded turbochargers—often larger billet wheels and revised housings—that increase both boost pressure and flow. These are typically a direct bolt-on replacement. Estimated cost: $3,800–$5,500 depending on whether you choose a hybrid or full replacement kit.

ECU Tune and TCU Calibration

A custom ECU tune is non-negotiable. EKLIPSE provides proprietary calibration files that optimize fuel mapping, ignition timing, and boost control for their hardware. But to handle 700 HP, you also need a transmission control unit (TCU) tune for the seven-speed dual-clutch transmission. This ensures shift pressures, timing, and clutch engagement can handle the extra torque. Estimated cost: $1,200–$2,500 for both ECU and TCU tuning.

High-Flow Exhaust System

Restrictive factory exhausts limit power. A full cat-back or downpipe-back EKLIPSE exhaust system reduces backpressure and improves spool time. Many owners also delete the secondary catalytic converters or opt for sport cats to reduce heat and restriction. Expect to pay $2,500–$4,500 for a quality stainless steel or titanium system with catalytic converters.

Intercooler Upgrade

Higher boost generates higher intake temperatures. Stock intercoolers heat-soak quickly, leading to power loss. An EKLIPSE front-mount intercooler with increased core volume and improved airflow can drop intake temperatures by 30–50°F, maintaining consistent power. Cost: $1,600–$3,200.

Fuel System Upgrades

To support 700 HP, you need more fuel than the stock injection system can deliver. This typically includes larger high-pressure fuel pumps (HPFP), upgraded injectors (often port injection added), and a boost-referenced fuel pressure regulator. EKLIPSE offers a complete fuel system kit that retains direct injection but adds auxiliary port injectors for higher flow. Estimated cost: $2,000–$3,500.

Intake System and Air Filters

Cold air intake systems with larger filters and smoother ducting reduce restriction. While not as critical as other items, they help spool the turbos faster. Cost: $400–$900.

  • Oil Cooler Upgrade: Track use or aggressive driving demands extra cooling. A larger oil cooler kit runs $800–$1,500.
  • Spark Plugs: One step colder plugs are essential for preventing pre-ignition. Cost: $100–$200.
  • Engine Mounts: Upgraded polyurethane or billet mounts reduce wheel hop and protect driveline parts. Cost: $400–$800.
  • Differential Cooling: If tracking the car, consider a differential cooler. Cost: $600–$1,200.

Detailed Cost Breakdown

Below is a realistic cost breakdown for a 700 HP AMG GT build using EKLIPSE parts. Prices reflect national averages for parts plus professional installation at a reputable shop. DIY labor can save $1,500–$3,000 but only if you have the tools and expertise.

Component Low Estimate High Estimate
Turbocharger Upgrade (EKLIPSE) $3,800 $5,500
ECU + TCU Tune (EKLIPSE Custom Calibration) $1,200 $2,500
Exhaust System (Cat-Back or Downpipe-Back) $2,500 $4,500
Intercooler Upgrade $1,600 $3,200
Fuel System Upgrade (HPFP + Injectors + Controller) $2,000 $3,500
Intake System $400 $900
Supporting Mods (spark plugs, mounts, cooling) $1,000 $2,500
Labor (estimated 30–50 hours at $100–$150/hr) $3,000 $7,500

Total Estimated Cost: $15,500 – $30,100

This wide range accounts for parts choices (new vs. remanufactured turbos, mid-range vs. top-tier exhaust), regional labor rates, and whether you include optional upgrades like an auxiliary fuel system or upgraded engine mounts. The previous cited range of $11,000-$20,500 was based on a more conservative parts list; the expanded table above reflects a more complete build with all supporting modifications.

Where the Money Goes – Breaking Down the Major Expenses

Turbochargers and Tuning – The Heart of the Build

The largest expense is the turbocharger upgrade and tuning, often consuming 40–50% of the budget. EKLIPSE’s turbo kits are engineered for the M178 engine, using larger compressor wheels and reinforced wastegates. The ECU tune is not generic; it is developed on a dynamometer specifically for the combination of parts you install. This calibration ensures that you do not just hit 700 HP on a single pull but maintain reliability over thousands of miles. Skimping on tuning by using a mail-order file can lead to detonation, high exhaust gas temperatures, or transmission failure.

Fuel System – The Bottleneck You Cannot Ignore

Stock fuel systems on the AMG GT can run out of capacity around 620–650 wheel horsepower. Upgrading to 700 HP requires a robust solution. EKLIPSE typically recommends a combination of upgraded high-pressure fuel pumps and port injection. This is more expensive than just a pump swap, but it provides the headroom needed for consistent fueling across all RPM ranges. Additionally, a flex-fuel sensor can allow you to run E85, which further reduces knock and increases power potential. Including flex-fuel capability adds about $300–$600 to the fuel system cost.

Exhaust and Cooling – Often Overlooked

A well-designed exhaust system does not just add power; it helps the turbospool faster and reduces underhood temperatures. The intercooler upgrade is critical for sustained performance. If you track the car or live in a hot climate, an auxiliary radiator or upgraded coolant pump should be added, pushing costs toward the upper end of the labor estimate.

Additional Considerations Beyond Part Costs

Warranty and Service Concerns

Any modification of this magnitude will void the factory powertrain warranty. Mercedes-Benz dealers can detect changes in ECU programming and component swaps. The cost of an extended aftermarket warranty is rarely available for modified cars. However, some performance shops offer their own warranty on parts and labor, typically one to two years. Factor that into your budget—or set aside $2,000–$4,000 as a contingency fund for potential issues.

Insurance Premium Increases

Adding 200+ horsepower to an already high-performance car will affect insurance. While rates vary, expect a 15–30% increase in your annual premium. Some insurers specialize in modified vehicles (like Hagerty or Grundy) and may offer agreed-value policies. Always disclose modifications; failure to do so can void your coverage in an accident.

Maintenance and Reliability

700 HP places extreme stress on every drivetrain component. Oil change intervals should be halved (every 3,000–5,000 miles). Spark plugs last 10,000–15,000 miles instead of 30,000. The transmission fluid and filter should be serviced every 20,000 miles if you drive aggressively. Tires and brakes will wear faster as well. Budget an additional $1,000–$2,000 per year in increased maintenance costs.

Resale Value Impact

Modified performance cars have a mixed resale history. A well-done build with documented parts and professional tuning can retain value among enthusiasts. However, many buyers prefer stock cars, so you may have to wait longer to sell or accept a lower price. Keeping the original parts and including them with the sale can help offset this. Some owners choose to reverse the build before selling, which adds labor costs but returns the car to factory condition.

Removing catalytic converters or tampering with emissions equipment is illegal in many states and countries. EKLIPSE offers sport catalytic converters that are compliant in most areas, but you should check local regulations. In California, for example, any modification that changes the ECU calibration is illegal for road use. Track-only builds avoid this issue, but street-driven cars may fail smog checks or face fines.

Real-World Performance Gains and Driving Experience

Beyond the numbers, what does 700 HP in an AMG GT feel like? The stock car already delivers a visceral punch, but the upgraded setup transforms the mid-range. Between 3,500 and 5,500 RPM, the EKLIPSE turbochargers produce a massive wave of torque, often exceeding 650 lb-ft at the wheels. The car becomes genuinely violent under full throttle, requiring careful throttle modulation. The exhaust note deepens and gains a sharper, more aggressive tone. On a racetrack, the extra power means much higher corner exit speeds, demanding upgraded brakes and suspension. Many owners pair this power level with coilover suspension and carbon-ceramic brake upgrades, adding another $4,000–$8,000 to the total build.

Is the Upgrade Worth It?

For an owner who has already enjoyed the stock or lightly modified AMG GT, a 700 HP EKLIPSE build is a transformative experience. The total investment of $15,000–$30,000 is less than the depreciation on a new luxury car and can make the AMG GT competitive with vehicles costing twice as much. However, it is not a project for beginners or those on a tight budget. Reliability depends on proper installation, quality parts, and a willingness to accept increased maintenance. Consulting with a shop experienced in EKLIPSE installations, such as those listed on EKLIPSE’s official site, and studying forums like MBWorld AMG GT forums can provide real-world feedback. Additional resources from Rennlist and 6SpeedOnline often have dedicated AMG GT build threads.

Final Thoughts

Upgrading your AMG GT to 700 HP with EKLIPSE parts is a serious investment in performance. The cost breakdown above gives you a realistic range from parts alone to a fully installed, tuned, and supported build. The true value lies not just in the horsepower number but in the engineering precision and driving involvement that comes from a well-sorted powertrain. Plan your budget, choose your shop carefully, and prepare for an adrenaline-filled experience that few cars can match.