The APR Stage 2 Turbocharger Upgrade for the Porsche 718 Cayman is one of the most effective bolt-on modifications for owners seeking a substantial power increase without swapping the entire engine. For an investment of around $3,500, this upgrade delivers a verified 60 horsepower gain, transforming the mid-engine sports car into a more thrilling machine on both street and track. This comprehensive guide explores every aspect of the upgrade — from the engineering behind it to real-world performance, installation requirements, costs, and key considerations before you commit.

What is the APR Stage 2 Turbocharger Upgrade?

The APR Stage 2 Turbocharger Upgrade is a direct replacement for the factory turbocharger on the 718 Cayman (982 chassis) equipped with the 2.0-liter or 2.5-liter turbocharged flat-four engine. APR, a leader in Volkswagen Audi Group (VAG) performance tuning, applies its extensive experience in forced induction to create a larger, more efficient turbocharger that flows significantly more air than the stock unit.

Unlike a simple ECU tune (Stage 1), this Stage 2 solution involves swapping out the turbocharger itself. The new unit features a larger compressor wheel, a revised turbine housing, and optimized internal geometry. These changes allow the engine to ingest a greater volume of air and expel exhaust gases more freely, setting the stage for a substantial horsepower gain when combined with the accompanying APR software calibration.

The upgrade is designed as a complete kit — the turbocharger assembly, all necessary gaskets and hardware, and a custom ECU tune are included. This ensures that the installation is as straightforward as possible for a professional workshop, and that the engine management system is properly calibrated to deliver safe, repeatable power.

Performance Gains: Dyno-Proven Horsepower and Torque

The headline figure of 60 additional horsepower is not an estimate — it is based on APR’s own dynometer testing and repeated by many independent shops. On a stock 718 Cayman base model (2.0L), the Stage 2 upgrade raises output from approximately 300 horsepower at the crank to over 360 horsepower. For the 718 Cayman S or GTS (2.5L with variable turbine geometry), the gain is similarly impactful, taking output from around 350 horsepower to over 410 horsepower.

Peak Torque and Curve Shape

Equally important is the torque increase. The APR Stage 2 turbocharger not only raises the peak torque number — typically a gain of 60 to 75 lb-ft — but also broadens the torque curve. The larger turbo spools quickly thanks to careful matching of the turbine housing A/R ratio, resulting in strong boost pressure from around 2,800 rpm all the way to redline. This transforms the car’s mid-range punch, making highway passing effortless and corner exits far more urgent.

Acceleration Improvements

  • 0-60 mph: Base 718 Cayman drops from about 4.9 seconds to 4.2 seconds (manual) or 4.0 seconds (PDK).
  • Quarter mile: ETs improve by 0.5–0.8 seconds, with trap speeds rising by 4–6 mph.
  • 60-100 mph: The mid-range torque cuts over a second off overtaking times.

For more detailed dyno graphs and vehicle-specific numbers, refer to the official APR product page: APR Stage 2 Turbocharger Upgrade for 718 Cayman.

Benefits Beyond Horsepower

While the extra 60 hp is the headline, the APR Stage 2 upgrade improves the driving experience in several other meaningful ways:

  • Throttle Response: The recalibrated ECU sharpen pedal response, eliminating the slight turbo lag present in the stock calibration. The larger turbo actually responds more eagerly than the stock unit at part throttle.
  • Sound: With increased airflow, the intake and exhaust note become more aggressive. The turbo spool is more audible, and the wastegate chatter adds character. The stock exhaust system is retained, so the overall sound remains refined but with a sportier edge.
  • Engine Reliability: APR’s tuning includes revised fuel and ignition maps, as well as enhanced knock control. The oiling system for the turbocharger is also improved, ensuring longevity even under sustained high-load use.
  • Track Readiness: The extra torque allows the car to maintain higher speeds through corners without needing to downshift as often, reducing driver fatigue during lapping sessions.

What’s Included in the APR Stage 2 Kit?

The kit is designed as a complete package, reducing the need for additional purchases. Contents include:

  • Turbocharger assembly — fully assembled with actuator.
  • Gasket set — new crush washers, O-rings, and turbo-to-manifold gasket.
  • Oil and coolant lines — pre-bent and sealed.
  • Hardware kit — bolts, studs, nuts, and clamps.
  • ECU tune file — loaded via APR’s software (cost included).
  • Installation instructions — detailed PDF from APR.

Note: The kit does not include an aftermarket intake or exhaust, but those modifications can be added later for additional gains (Stage 3 with intercooler and downpipe is a future step).

Installation Process and Requirements

Installing the APR Stage 2 turbocharger is a significant job that requires mechanical skill and specialized tools. The process generally takes 8 to 12 hours for a professional technician. Here is an overview of the major steps:

  1. Drain fluids — engine oil and coolant must be partially drained.
  2. Remove factory turbocharger — this involves disconnecting charge air pipes, exhaust downpipe, coolant and oil lines, and the heat shields.
  3. Prepare the mounting surfaces — clean the oil return flange and exhaust manifold mating face.
  4. Install the APR turbocharger — using new gaskets and hardware, torque bolts to spec.
  5. Reconnect all lines — oil supply and return, coolant feed and return.
  6. Reassemble induction and exhaust — reinstall the intake ducting and factory downpipe (or aftermarket).
  7. Refill fluids — fresh oil and coolant.
  8. ECU tuning — APR software is flashed using their OBD-II cable or at an authorized dealer.
  9. Prime the turbo — crank the engine with the fuel pump fuse pulled to circulate oil before starting.
  10. Test drive and log — verify boost pressure, fuel trims, and knock levels.

Because of the complexity and the need for ECU programming, APR strongly recommends having the upgrade installed by an APR-authorized dealer. Many independent Porsche specialists are also comfortable with this procedure. Attempting a DIY install without proper experience and VAG diagnostic software may lead to issues such as boost leaks, oil starvation, or improper alignment.

ECU Tuning and Calibration

The heart of the APR Stage 2 system is the custom calibration that manages the larger turbocharger. This software is not a generic reflash — it is developed on a loaded engine dyno at APR’s facility in Opelika, Alabama. The tune adjusts:

  • Boost pressure targets — typically 18–20 psi depending on fuel octane.
  • Fuel injector pulse width — to maintain correct air-fuel ratio under high load.
  • Ignition timing — optimized for the turbo’s flow characteristics.
  • Variable valve timing — adjusted for improved spool and top-end power.
  • Oxygen sensor feedback — recalibrated for closed-loop operation.

The software is locked to the vehicle’s VIN and cannot be transferred. APR offers a tool called the APR Mobile interface that allows the owner to switch between the Stage 2 file and the stock program if desired. For more details on the software, visit APR’s FAQ section: APR Support and FAQs.

Cost Breakdown and Value Analysis

The $3,500 price tag is an approximate total. Below is a realistic breakdown:

Component Estimated Cost
APR Stage 2 Turbocharger Kit (including ECU tune) $2,999 – $3,299
Installation labor (8–12 hours at $100–$150/hr) $800 – $1,800
Fluids and minor supplies $100 – $200
Total estimated range $3,900 – $5,300

The $3,500 figure often quoted assumes a DIY install, which is not recommended for most owners. With professional installation, the actual outlay is higher. However, comparing the cost to the horsepower gain — roughly $60–$70 per horsepower — represents excellent value compared to other performance modifications like a exhaust system or lightweight wheels that offer far smaller gains for similar money.

Compatibility and Vehicle Requirements

The APR Stage 2 turbocharger upgrade is available for the following Porsche 718 models:

  • 718 Cayman (base) — 2.0L turbocharged flat-four (2017–current)
  • 718 Cayman S — 2.5L turbocharged flat-four with VTG
  • 718 Cayman GTS 4.0 — does NOT apply (requires different system)
  • 718 Boxster / Boxster S — same engine as Cayman counterparts

Important: The upgrade is not compatible with the naturally aspirated 4.0L flat-six in the GTS 4.0 and GT4 models. Also, cars equipped with the PDK automatic transmission will benefit from a PDK tune (available from APR separately) to handle the increased torque and improve shift firmness.

Vehicle must be running 93-octane (RON 98) fuel or better for full power. APR also offers a 91-octane calibration, but peak output is reduced by approximately 10–15 hp.

Warranty and Insurance Considerations

Factory Warranty

Installing the APR Stage 2 turbocharger upgrade will void the portion of the Porsche factory warranty related to the engine, turbocharger, and drivetrain. APR products themselves carry a limited warranty against defects, but that does not cover claims denied by Porsche due to modification. Some owners choose to wait until their factory warranty expires before adding this upgrade.

Insurance

Any power-enhancing modification can increase your insurance premium. It is essential to inform your provider about the changes. Some specialty insurers (e.g., Hagerty for track-focused use) are more accommodating, while mainstream carriers may surcharge. Obtain a quote before proceeding.

Alternative Upgrades and Comparison

Before committing to Stage 2, consider other APR tuning options:

  • APR Stage 1 ECU Tune: ~$700, gains of 40–50 hp, no hardware changes. Best value but limited to stock turbo.
  • APR Stage 3 (if available): Involves an even larger turbo, intercooler, downpipe, and intake. Over $6,000, gains of 100+ hp, but more invasive and less daily-drivable.

The Stage 2 strikes a balance — it is the most cost-effective way to add significant power without needing supporting mods like an exhaust or intercooler (though those help). For most enthusiasts chasing a noticeable performance uplift, Stage 2 is the sweet spot.

Frequently Asked Questions

Is the APR Stage 2 upgrade reliable for daily driving?

Yes, APR calibrates the software conservatively with safety margins. Many owners report thousands of miles of trouble-free use. However, the larger turbo does increase heat load — regular oil changes (5,000 miles) and monitoring coolant temps are advised.

Will I need a different downpipe?

No, the factory downpipe can be reused. However, pairing the upgrade with a high-flow downpipe can free up an additional 10–15 hp and improve spool.

Can I install the turbocharger myself?

It is possible for an experienced home mechanic with VAG diagnostic tools, but not recommended. Mistakes during installation can cause serious engine damage. Professional installation is strongly advised.

Does the upgrade require an intercooler upgrade?

Not required, but an upgraded intercooler reduces intake air temperatures, allowing more consistent power in hot weather. APR offers a matching intercooler as a companion product.

Conclusion

The APR Stage 2 Turbocharger Upgrade is a transformative modification for the Porsche 718 Cayman. At approximately $3,500 for the kit (plus installation), the gain of 60 horsepower and dramatically improved torque delivery make it one of the most impactful investments an owner can make. It elevates the car from a competent sports car to a genuine performance machine that can challenge older 911 models in a straight line and on track.

Before proceeding, weigh the warranty and insurance implications, ensure you have access to quality fuel, and choose an experienced installer. With those boxes checked, the APR Stage 2 upgrade will reward you every time you press the start button and feel the surge of power that Porsche left on the table.