The Veloster N: A Hot Hatch Icon

Hyundai’s Veloster N earned its reputation as a genuinely thrilling front-wheel-drive hot hatch straight from the factory. With a 2.0-liter turbocharged inline-four producing 275 horsepower and 289 lb-ft of torque (with the optional Performance Pack), it offers sharp handling, a playful chassis, and a raspy exhaust note. Yet for many enthusiasts, stock power is just the starting point. The aftermarket has responded with a range of upgrades, and one of the most comprehensive and proven options is the APR Stage 3 Kit. This system takes the Veloster N from a peppy daily driver to a legitimate 350-plus-horsepower weapon. In this article, we break down exactly what the kit includes, how much power it actually adds, what’s involved in installation, and what supporting modifications you may need to keep everything reliable.

APR Stage 3 Kit: What’s Included?

The APR Stage 3 Kit is not just a reflash or a single bolt-on; it is a complete turbo system upgrade engineered to flow significantly more air and fuel. APR, a well-known name in Volkswagen and Audi tuning, has applied the same rigorous development to the Veloster N’s Theta II engine. The kit is designed as a direct bolt-on replacement for the factory turbocharger and related components, meaning no permanent modifications are required. Here is what ships with the kit:

  • High-Flow Turbocharger – A larger compressor wheel and turbine housing that flows roughly 40–50% more air than the stock unit. The turbo is ball-bearing for faster spool and better transient response.
  • Upgraded Intercooler – A cast aluminum core with significantly more volume and surface area to reduce intake air temperatures (IATs) under sustained boost. Reduces heat soak on track or during aggressive street driving.
  • Performance Intake System – A larger air box, high-flow filter, and wider diameter intake pipe to reduce restriction on the inlet side. Includes a heat shield to pull cooler air from outside the engine bay.
  • High-Pressure Fuel Pump (HPFP) – An upgraded pump capable of maintaining enough fuel pressure at the higher flow rates demanded by the larger turbo. Crucial for preventing lean conditions under load.
  • Custom ECU Tune – APR-specific software optimized for the hardware package. The tune adjusts boost targets, fuel mapping, ignition timing, and cam phasing. It is designed for 93-octane pump gas (with optional flex-fuel support for E85).

The kit is sold both as a full package and as individual pieces, but APR strongly recommends the complete system for maximum gains and reliability. The ECU tune is a critical part of the package; without it, the engine management cannot properly regulate boost or fuel delivery, risking detonation.

Dyno-Proven Power Gains: Stock vs. Stage 3

APR publishes independent dyno results from a third-party facility. On a chassis dynamometer in 93-octane mode, the Veloster N with the Stage 3 Kit produces between 350 and 370 wheel horsepower. At the crank, that translates to approximately 390–410 horsepower. Torque similarly climbs to over 400 lb-ft at the wheels, with some runs showing as high as 420 lb-ft. Compare that to a stock Veloster N on the same dyno: roughly 240–250 wheel horsepower and 260–270 lb-ft of torque. The gain is significant: about 100–120 wheel horsepower and 130–150 lb-ft of torque.

Peak Horsepower and Torque

  • Stock (crank): 275 hp / 289 lb-ft
  • Stock (wheels): ~245 hp / ~265 lb-ft
  • APR Stage 3 (crank): ~390 hp / ~410 lb-ft
  • APR Stage 3 (wheels): ~355 hp / ~380 lb-ft

These numbers represent a best-case scenario on a dyno in optimal conditions. Real-world output can vary based on altitude, ambient temperature, fuel quality, and overall engine health. Still, the trend is clear: the Veloster N transforms into a mid-400-horsepower-level machine at the crank when running the full Stage 3 kit and 93-octane fuel.

Full Power Curve Improvements

Just as important as the peak numbers is how the power is delivered. The stock turbo runs out of steam after about 5,500 RPM, with power tapering off. The APR Stage 3 turbo maintains boost all the way to redline (6,800 RPM), giving the car a much stronger top-end pull. At the same time, the ball-bearing design means spool is not severely penalized. Boost threshold moves from about 2,800 RPM to 3,200–3,500 RPM, but the torque curve is flatter and carries much higher torque from 4,000 RPM onward. This results in a punchy mid-range and a screaming top-end that makes the car feel significantly faster in all gears.

Installation Deep Dive

Installing the APR Stage 3 Kit is a major job. While a skilled home mechanic with proper tools can manage it, most owners opt for a professional installation at a certified APR dealer. The process generally takes 8–12 hours for a shop experienced in Veloster N work. Here is a step-by-step look at what is involved:

  1. Drain Fluids & Remove Front Bumper – The intercooler sits behind the lower grille, so the front fascia must come off. Coolant and oil are often drained to access coolant lines and oil feed/drain lines for the turbo.
  2. Remove Stock Turbo and Intercooler – The factory turbo, wastegate actuator, and intercooler are removed. The intake manifold may also be taken off to reach the turbo mounting bolts. The stock fuel pump is replaced at this point if the upgraded HPFP is part of the kit.
  3. Install Upgraded Intercooler – The new, larger intercooler bolts in using factory mounts. It may require trimming or modifying the lower grille opening for proper airflow; APR includes instructions for this.
  4. Install High-Flow Turbo – The new turbo is bolted in place with new gaskets. The oil feed and return lines are reconnected. The turbo’s wastegate actuator is pre-calibrated on the kit, but some adjustment may be needed for proper boost control.
  5. Install Intake System – The factory air box is removed and replaced with the APR intake. The larger diameter tube connects to the turbo inlet. The MAF sensor is transferred.
  6. Reassemble and Flash ECU – Once all hardware is in place, the bumper is reinstalled. The ECU is flashed using APR’s software via the OBD-II port. The tune includes multiple files (e.g., 93 octane, 91 octane, and an optional E85 file). The car is then started and checked for leaks.
  7. Break-In Procedure – APR recommends a short break-in period for the new turbo—about 500 miles of varied driving, avoiding sustained high boost. After that, the car is ready for full-throttle pulls.

Because the turbo sits low on the engine, accessibility is poor, and many fasteners are in tight spaces. A lift, specialized tools (like turbo socket wrenches), and patience are essential. Expect to pay $1,500–$2,500 in labor at a reputable shop.

Supporting Modifications for Reliability

Pushing an engine from 275 to 400 crank horsepower requires more than just the Stage 3 kit. The stock drivetrain and cooling systems have limits. Here are the supporting modifications that most track-oriented owners add:

  • Upgraded Clutch – The stock clutch on the manual-transmission Veloster N begins to slip around 350–380 lb-ft of torque at the wheels. For Stage 3 power, a heavy-duty clutch (e.g., ACT, South Bend, or Competition Clutch) is highly recommended. If you have the DCT, consider a transmission cooler upgrade and increased fluid service intervals.
  • Downpipe and Exhaust – The stock catalytic converter is restrictive. A high-flow catted or catless downpipe (3-inch) reduces backpressure and lets the turbo breathe, adding 10–20 hp on top of the kit. Pairing it with a cat-back exhaust improves sound and spool.
  • Intercooler Hard Pipes – While the APR intercooler comes with silicone couplers, some owners upgrade to aluminum hard pipes to reduce expansion under high boost.
  • Engine and Transmission Mounts – Under hard acceleration, the stock mounts allow significant wheel hop and engine movement. Stiffer mounts (Powerflex, Boomba) improve traction and shift feel.
  • Brake Upgrade – With 400 hp, the stock brakes, while decent, can fade on repeated hard stops. Upgraded pads, stainless steel lines, and high-temperature fluid are wise. A full big brake kit (AP Racing, StopTech) is ideal for track use.
  • Wider Tires – The stock 235/40R18s are overwhelmed by the torque. A 245 or 255-width tire (e.g., Michelin Pilot Sport 4S, Yokohama Advan A052) dramatically improves acceleration and cornering grip.

Without these supporting mods, you may still drive the car in a straight line, but reliability and drivability will suffer, especially if you frequent road courses or drag strips.

Real-World Driving Impressions

On the street, the APR Stage 3 Veloster N feels like a different car. The throttle response sharpens, and boost comes on with a distinct surge around 3,500 RPM. Where the stock car feels quick, the Stage 3 car feels genuinely fast, pinning you into the seat as it pulls all the way to the limiter. In-gear acceleration, like 60–100 mph, improves by roughly 2 seconds. 0–60 mph times drop from around 5.1 seconds to the mid-3-second range with a good launch and sticky tires. Quarter-mile times fall from a stock 13.7–14.0 seconds to the low 12-second range at 115–118 mph.

The exhaust note deepens and becomes more aggressive, especially with a downpipe. The turbo spool is audible through the intake, and the blow-off valve (if using the recirculating APR setup) adds mechanical character. The car still retains its daily-driver civility at part-throttle; the tune is refined and doesn't cause surging or drivability issues. Cold start and idle are smooth.

Comparing APR Stage 3 to Other Tuning Options

The Veloster N has a robust tuning ecosystem. Here is how the APR Stage 3 stacks up against common alternatives:

  • Stage 1 (ECU Tune Only): ~300–320 hp at the crank. All stock hardware. ~$700–$900. Noticeable gain but no top-end surge. Limited torque capacity of the stock clutch is still a risk.
  • Stage 2 (Downpipe + Tune): ~330–350 hp at the crank. Uses stock turbo. Requires downpipe and intercooler often. ~$1,500–$2,000. Good mid-range punch but the stock turbo still runs out of steam up top.
  • APR Stage 3 (Full Turbo Kit): ~390–410 hp at the crank. Total cost around $5,000–$6,000 for the kit plus labor. Delivers the highest peak power and best top-end performance. Requires supporting mods for full reliability.
  • Big Turbo Kits (Pure Turbo, Garrett): Some aftermarket options offer even larger turbos good for 450+ hp. These often require built internals, upgraded fuel system (port injection), and custom tuning. More expensive and less drivable.

The APR Stage 3 represents a sweet spot: it is a well-engineered, CARB-compliant (in many states) package that doesn't require engine internals for the power level. It remains highly streetable while offering track-capable performance.

Considerations and Potential Drawbacks

Before buying the kit, weigh these factors:

  • Warranty: Installing the APR Stage 3 kit will almost certainly void the Hyundai powertrain warranty. APR offers a limited warranty on its parts, but the engine itself is not covered by Hyundai if the tune is detected.
  • Insurance: You must inform your insurer of the modification. Some companies may refuse coverage or increase premiums. Hagerty or specialty insurers may offer agreed-value policies for modified cars.
  • Emissions: The APR kit with the included tune is designed to maintain catalyst efficiency but may still trigger a check-engine light in states with strict OBD-II testing. The catless downpipe option will fail visual inspections.
  • Fuel Requirement: The kit demands 93 octane for the maximum tune. If you only have access to 91 octane, power drops to around 340–350 whp. E85 (with the optional flex-fuel sensor) can boost power further but reduces fuel economy significantly.
  • Clutch Life: Even with a heavy-duty clutch, aggressive launches will shorten its lifespan. Plan on replacing the clutch every 20,000–30,000 miles if you track the car frequently.

Conclusion: Is the APR Stage 3 Worth It?

The APR Stage 3 Kit for the Hyundai Veloster N delivers on its promise: it transforms a fun hot hatch into a genuine performance machine capable of embarrassing cars that cost twice as much. The power gains are substantial, the engineering is proven, and the drivability remains acceptable for daily use. However, the true cost extends beyond the kit price—you should budget for a clutch upgrade, better tires, and professional installation. For the enthusiast who wants a turnkey solution to reach over 350 whp without piecing together a custom setup, the APR Stage 3 Kit is one of the best investments you can make for your Veloster N. Check APR’s official product page for current pricing and application details, and read community feedback on VelosterN.org for real-world owner experiences.