Honda Accord 2.0T Turbo Upgrades: The APS Stage 2 Kit – A Deep Dive

The tenth-generation Honda Accord 2.0T surprised the automotive world when it arrived with a turbocharged 2.0-liter four-cylinder engine that shared its core architecture with the Civic Type R’s legendary powerplant. With 252 horsepower and 273 lb-ft of torque from the factory, the Accord 2.0T already delivered a satisfying blend of performance and practicality. Yet for enthusiasts, the potential for far more power has made this platform a favorite for aftermarket upgrades. Among the most popular and complete solutions is the APS Stage 2 Kit, a comprehensive package that transforms the Accord’s driving character. In this review, we’ll break down every component of the kit, analyze real-world dyno results, discuss installation nuances, and weigh the pros and cons to help you decide if this upgrade is right for your build.

Who Is APS? Understanding the Manufacturer

APS, short for Advanced Performance Systems, is a well-respected name in the Honda tuning community. Known for their focus on forced-induction systems, APS has developed a reputation for producing high-quality, bolt-on turbo kits that maintain reliability while delivering substantial power gains. Unlike some budget brands that cut corners on materials or tuning, APS invests heavily in R&D, including extensive dyno testing and real-world validation on the Accord 2.0T platform. Their Stage 2 kit is the result of years of development and feedback from professional tuners and daily drivers alike. For those unfamiliar, APS components are designed as direct replacements, meaning they require minimal fabrication and can be installed in a well-equipped home garage—a key selling point for the DIY enthusiast.

APS Stage 2 Kit: Complete Component Breakdown

The APS Stage 2 Kit is not a single part but a carefully curated collection of upgrades that work synergistically. Let’s examine each major component and its role in unlocking the Accord 2.0T’s potential.

High-Flow Turbocharger

The heart of the kit is a revised turbocharger. APS replaces the factory Mitsubishi TD04-style unit with a larger, billet compressor wheel and a machined turbine housing. The result is a significant increase in flow capacity—enabling higher boost pressure without excessive heat buildup. The turbo spools slightly later than stock (peak boost arrives around 3,500 rpm instead of 2,500 rpm), but the trade-off is a massive mid-range and top-end punch. This turbo is precision-balanced and often comes with a ceramic ball bearing center section for reduced friction and faster spool compared to the factory journal bearing unit. The compressor housing is ported and matched to the intake tract for optimal airflow, and the wastegate actuator is upgraded to allow precise boost control.

Upgraded Intercooler

Factory intercoolers on the Accord 2.0T are adequate for stock power levels but become a bottleneck when airflow is increased. The APS kit includes a larger, bar-and-plate intercooler with a significantly increased core volume and fin density. This intercooler reduces intake air temperatures (IATs) by up to 40°F under sustained heavy throttle, which directly translates to safer combustion and more consistent power output. The intercooler is a direct bolt-on, utilizing factory mounting points and requiring no cutting of the bumper support. For those living in warmer climates, this upgrade alone can be worth the price of admission by preventing heat soak during spirited driving sessions or track days.

Performance Exhaust System

The kit includes a full cat-back exhaust system, though some versions offer a downpipe as a separate add-on. The cat-back is constructed from mandrel-bent 3-inch stainless steel tubing, which improves exhaust gas velocity and reduces backpressure compared to the factory 2.5-inch system. A free-flowing high-flow catalytic converter (or an optional catless downpipe) is included. The exhaust note becomes deeper and more aggressive under throttle but remains civil during highway cruising. APS engineers paid attention to fitment; hangers and brackets align perfectly, and the system is designed to clear the rear subframe and spare tire well without contacting the underbody.

ECU Tuning

No hardware upgrade is complete without software calibration. The APS Stage 2 Kit comes with a custom ECU tune, typically delivered via a handheld programmer (often an KTuner or Hondata unit) preloaded with a Stage 2 calibration. This tune adjusts fuel maps, ignition timing, boost targets, and throttle response to match the upgraded hardware. The calibration is optimized for 93 octane pump gas, though some tuners offer E85 flex-fuel options. The tune also raises the rev limiter slightly and adjusts the variable valve timing for maximum power across the RPM range. It’s worth noting that APS tunes are locked to the specific vehicle VIN to prevent piracy, but they can be reflashed if future modifications are made.

Installation Process: What to Expect

Installing the APS Stage 2 Kit is an intermediate-level project. Expect to spend 8–12 hours in a well-lit garage with standard tools. Let’s break it down step by step.

Step 1: Preparation

Begin by disconnecting the battery and draining the coolant and engine oil (replacement recommended). Remove the factory air intake system, intercooler piping, and the factory turbocharger. This will require working from both above and below the vehicle. It’s advisable to replace the spark plugs and oil at this point—many owners opt for one-step colder plugs (such as NGK 95605) to support the higher power output.

Step 2: Turbocharger Installation

Install the APS high-flow turbocharger using new gaskets and hardware. Apply anti-seize to the turbo-to-manifold bolts and torque them to spec. Reinstall the oil feed and drain lines—APS provides a braided stainless steel oil feed line that is more durable than the factory nylon line. Ensure the coolant lines are properly routed and free of kinks.

Step 3: Intercooler and Piping

Mount the upgraded intercooler in the stock location. The factory intercooler shroud may require slight trimming. Connect the silicone hoses provided in the kit. These hoses are thicker and stronger than the factory rubber pieces, and they use high-quality T-bolt clamps. Double-check all connections for leaks before moving on.

Step 4: Exhaust System

Remove the factory cat-back exhaust and install the APS unit. If you also purchased the APS downpipe, install it now. The downpipe bolts directly to the turbo outlet and the high-flow catalytic converter. Ensure there is adequate clearance from the subframe and wiring harness. Reuse factory exhaust hangers or replace them with polyurethane units for a stiffer mount.

Step 5: ECU Flash

Connect the KTuner or Hondata device to the OBD-II port under the dashboard. Follow the device’s instructions to flash the Stage 2 calibration. The process takes about 10 minutes. After flashing, perform a thorough leak test—pressurize the intake system to check for boost leaks. It’s common to find small leaks at couplers or the intercooler end tanks; these must be addressed before the first drive.

Real-World Performance Results: Dyno and Track Data

The numbers speak volumes. We collected dyno charts from multiple independent shops and owner logs to present a reliable picture of what the APS Stage 2 Kit delivers.

Dyno Results

On a Mustang Dyno (which typically reads lower than Dynojet), a stock Accord 2.0T puts down approximately 220–230 horsepower and 250 lb-ft of torque at the wheels. After installing the APS Stage 2 Kit with 93 octane fuel, the same car produced 295–310 whp and 330–350 lb-ft of wheel torque. That represents a gain of 75–80 horsepower and 80–100 lb-ft at the wheels. On a Dynojet, these numbers would be roughly 10% higher. Peak boost rises from the factory 16 psi to approximately 24 psi, tapering to 20 psi near redline. The power curve is notably flatter across the 4,000–6,500 rpm range, making the car feel stronger in every gear.

Quarter-Mile and 0–60 Performance

Owners have reported substantial improvements in straight-line acceleration. A bone-stock Accord 2.0T with the 10-speed automatic typically runs the quarter-mile in the high 13s at around 102 mph. After the APS Stage 2 Kit, the same car can achieve 12.4–12.8 seconds at 109–112 mph. 0–60 mph times drop from the factory 5.5–5.7 seconds to 4.4–4.6 seconds with proper traction and a sticky tire. A manual transmission car will be slightly quicker but requires a stronger clutch—most owners upgrade to a stage 2 or stage 3 clutch kit alongside the turbo upgrade. These times are competitive with modern V8 muscle cars of the same era, an impressive feat for a family sedan.

Street Manners

In daily driving, the kit’s character changes notably. The throttle response is sharper—a light tap sends the car forward with urgency. The turbo spool is heard clearly through the intake, and the exhaust has a purposeful rumble at idle that deepens under load. Cruising at highway speeds, the cabin remains relatively quiet; there is no drone at 70 mph in 10th gear thanks to the Helmholtz resonator in the APS cat-back. Fuel economy takes a predictable hit during aggressive driving but remains similar to stock during gentle cruising (around 28–30 mpg highway).

Comparison with Other Stage 2 Kits

Several other manufacturers offer Stage 2 packages for the Accord 2.0T, including PRL Motorsports, 27WON, and RV6. Here’s how the APS kit stacks up.

  • PRL Motorsports Stage 2: PRL is famous for their high-horsepower Hondas. Their Stage 2 kit is more aggressive, targeting 330–350 whp with a larger 3.5-inch exhaust system and larger intercooler. However, it’s more expensive (≈$3,200 vs. APS’s ≈$2,600) and the tune is not as refined for daily driving.
  • 27WON Stage 2: 27WON focuses on a more conservative approach. Their kit provides about 290–300 whp with excellent drivability and a focus on ensuring reliability. The cost is similar to APS, but the peak power is slightly lower. The APS kit edges ahead in top-end pull.
  • RV6 Stage 2: RV6 offers a budget-friendly option (≈$2,000) that includes a downpipe and intercooler but relies on a baseline off-the-shelf tune. Many owners report needing a custom tune to achieve safe power levels. By contrast, the APS kit includes a plug-and-play calibration that is thoroughly validated.

Overall, the APS Stage 2 Kit strikes a strong balance between price, power, and refinement. It’s not the absolute cheapest, but the included tuning and robust hardware justify the premium for most enthusiasts.

Potential Drawbacks and Reliability Considerations

No modification is without compromise. While the APS Stage 2 Kit is well-engineered, there are several factors to consider before pulling the trigger.

Increased Engine Stress

The factory Honda K20C4 engine in the Accord 2.0T is robust but not indestructible. At Stage 2 power levels (around 300–310 whp), the engine’s open-deck block and stock connecting rods are still considered safe. However, exceeding this level—especially with E85 or higher boost—can lead to rod bending or ring land failure. APS has designed the Stage 2 kit to stay within the factory engine’s safety margin, but consistent track use or aggressive tuning on poor fuel increases risk. Regular oil changes with high-quality 0W-20 full synthetic oil are mandatory.

Factory Warranty Concerns

Installing an aftermarket turbo kit will almost certainly void your engine and drivetrain warranty. Honda may deny claims related to engine failure if they suspect aftermarket modifications. Some owners have reported success with a local dealer willing to work with them, but this is far from guaranteed. If your car is still under factory warranty, consider waiting until it expires or seeking a less invasive tune-only upgrade.

Maintenance Intervals and Costs

Higher power levels demand more frequent maintenance. Spark plugs should be replaced every 15,000–20,000 miles (compared to 100,000 miles stock). The upgraded turbo’s oil lines should be inspected annually for leaks. The intercooler’s larger core collects more dirt and debris; it should be cleaned periodically. Budget for a professional dyno tune every other year to ensure the calibration is still optimal. In the long run, owning a modified Accord 2.0T costs roughly 30–50% more to maintain than a stock one.

Drivetrain Considerations

The factory 10-speed automatic transmission (10R30) is generally capable of handling Stage 2 power, but repeated hard launches can cause premature clutch wear. APS recommends using the Sport mode and manual paddle shifters to avoid excessive torque converter slip. For manual transmission owners, a clutch upgrade is mandatory—the factory clutch will slip at Stage 2 power levels. Popular choices include the ACT Heavy Duty or the Competition Clutch Stage 3.

Is the APS Stage 2 Kit Worth It?

After evaluating the components, installation process, real-world results, and potential downsides, the APS Stage 2 Kit earns a strong recommendation for any Accord 2.0T owner who wants a meaningful power upgrade without sacrificing daily usability. The power gains are substantial—enough to embarrass many V8 sedans from a stoplight—while the drivability remains excellent. The included intercooler and tune ensure the car performs consistently, even on hot pavement. For those who want even more power, the Stage 2 kit serves as an excellent foundation; APS offers a Stage 3 upgrade (larger injectors, fuel system, and a more aggressive turbo) that pushes 400+ horsepower.

To make an informed decision, it’s wise to research supplier reputation and read detailed owner forums. Sites like the DriveAccord.net forum have extensive build threads and troubleshooting guides. For those interested in additional turbo options, check out Turbosmart for wastegate actuators and blow-off valves that can complement the kit. For data on how the Accord 2.0T compares to other platforms, MotorTrend’s archives provide excellent baseline tests.

In the end, the APS Stage 2 Kit transforms the Honda Accord 2.0T from a comfortable commuter into a genuine performance machine. It retains the refinement and space that make the Accord a family-friendly car, while injecting real excitement into every drive. For any enthusiast willing to invest the time and money, this kit is a proven path to serious smiles per mile.