How Much Horsepower Does the Z1 Motorsports 370Z Supercharger Add? Up to 480 HP!

The Nissan 370Z is already a formidable sports car straight from the factory, but for enthusiasts craving more power, forced induction is the next logical step. Among the most popular and well-engineered options is the Z1 Motorsports centrifugal supercharger kit. This article provides a detailed, data-driven look at the horsepower gains, installation considerations, supporting modifications, and real-world performance of the Z1 supercharger system for the 370Z. By the end, you’ll understand exactly what it takes to push your VQ37VHR engine toward the 480-horsepower mark.

Understanding the Z1 Motorsports Supercharger System

Z1 Motorsports has built a strong reputation in the Nissan performance community for producing high-quality, bolt-on forced induction kits. Their supercharger system for the 370Z is a centrifugal design, meaning it uses a belt-driven impeller to compress intake air and force it into the engine. Unlike a positive-displacement supercharger (like a roots or twin-screw type), a centrifugal unit builds boost progressively with engine RPM, offering linear power delivery similar to a turbocharger but without the lag.

The kit is engineered specifically for the VQ37VHR engine found in the 370Z. It includes a precision-machined supercharger head unit, an air-to-air intercooler, custom cast aluminum intake piping, high-flow injectors, and a dedicated oil feed system. Z1 provides the kit in several configurations – from a basic “stage 1” to a fully built “stage 2+” with larger intercoolers and supporting fuel system upgrades. The horsepower output ultimately depends on which stage you choose and how aggressively you tune.

Base Line: Stock 370Z Horsepower

Before calculating gains, it’s important to establish a baseline. Factory specifications list the 370Z at 332 horsepower and 270 lb-ft of torque at the crank. However, most owners and dyno operators see around 270-280 wheel horsepower on a Dynojet or Mustang dyno in stock trim. The drivetrain loss through the manual or 7-speed automatic transmission accounts for roughly 15-18%.

When adding a supercharger, the real-world measurement is wheel horsepower (whp). The Z1 Motorsports kit is advertised to produce up to 480 crank horsepower. On a typical dyno, that translates to roughly 400-410 whp on a conservative tune with pump gas. With higher octane fuel, race gas, or E85, and additional supporting modifications, the same kit can exceed 450 whp at the wheels – which corresponds to well over 500 crank horsepower.

Detailed Horsepower Gains by Stage

Stage 1 – Basic Kit (8-10 psi)

The entry-level Z1 supercharger kit includes the supercharger head unit, intercooler, piping, and a basic tune. On 91-93 octane pump gas, owners typically see 380-400 whp (approximately 450-475 crank horsepower). This represents a gain of about 100-120 wheel horsepower over stock. Torque also increases to roughly 310-330 lb-ft at the wheels.

Stage 2 – Intercooler Upgrade & Higher Boost (10-12 psi)

With a larger intercooler and a more aggressive tune, the Z1 kit pushes closer to 420-440 whp. This boost level requires careful attention to fuel delivery – often an upgraded in-tank pump and larger injectors. At this power level, the 370Z becomes a serious performer, capable of running mid-11 second quarter-mile times with good traction.

Stage 2+ – E85 & Maximum Effort (12-15 psi)

For enthusiasts willing to run E85 (corn fuel) or race gas, the Z1 kit can be tuned to produce 460-480 whp (exceeding 550 crank horsepower). This requires a full fuel system upgrade: dual pumps, larger injectors (1050cc or bigger), and often a return-style fuel system with a boost reference regulator. At these power levels, the VQ37VHR engine is approaching its factory fuel system limits, and internal modifications (forged pistons, rods) are recommended for long-term reliability.

Factors That Influence Final Horsepower Output

Not every Z1 supercharged 370Z will hit the same numbers. Several variables affect the final output:

  • Tuning Quality: A custom dyno tune by an experienced Nissan tuner is critical. Off-the-shelf tunes leave power on the table or risk knock. Fuel maps, ignition timing, cam timing, and boost control must be carefully calibrated.
  • Fuel Octane: 91 octane may require conservative timing, while 93 allows a bit more advance. E85 (around 105 octane) provides significant knock resistance and cooler combustion, enabling higher boost and more aggressive timing.
  • Ambient Temperature & Intake Temperature: A larger intercooler or an auxiliary heat exchanger can lower intake air temps (IAT), preventing knock and maintaining power run after run.
  • Exhaust System: A high-flow cat-back exhaust with test pipes or high-flow cats reduces backpressure, allowing the supercharger to flow more efficiently. Gains of 10-20 whp are common when pairing a cat-back with the supercharger.
  • Engine Health: Compression test results and oil quality matter. A high-mileage engine may not handle the extra stress as well as a low-mileage or rebuilt unit.

Supporting Modifications That Maximize Power

To get the most from the Z1 supercharger, consider these upgrades:

Fuel System

At 400+ whp, the factory fuel pump and injectors run out of capacity. Z1 recommends their 340lph in-tank pump upgrade at a minimum. For E85 or higher boost, a dual-pump setup or a JPC return-style fuel system is necessary. Injectors should be at least 750cc for pump gas and 1050cc or larger for E85.

Cooling

The air-to-air intercooler included in the kit works well for street driving, but a larger core or a water-methanol injection system can reduce IATs significantly. On hot track days, an upgraded radiator and oil cooler are also wise investments.

Clutch & Drivetrain

The factory clutch in manual 370Zs is marginal above 400 whp. A clutch upgrade like a South Bend Stage 3 or Competition Clutch is essential. The automatic transmission (7-speed) can handle moderate power but may benefit from a transmission cooler and a torque converter upgrade for racing.

Engine Internals

While the VQ37VHR has robust forged connecting rods from the factory, the pistons are hypereutectic cast and can fail under sustained high boost or detonation. For 480+ whp, many owners opt for forged pistons (CP-Carrillo or JE) and upgraded rod bolts. However, at stage 1 power levels, stock internals are generally reliable with proper tuning.

Installation Overview

The Z1 supercharger kit is designed as a relatively straightforward bolt-on project, but it requires several hours of labor. A competent DIY mechanic with basic tools and a garage can complete the install over a weekend. However, the tuning step requires a dyno session with a professional. Here is a summary of the installation process:

  1. Disconnect battery and drain coolant.
  2. Remove the stock air intake system – the air box, intake tube, and mass airflow sensor.
  3. Remove the front bumper cover and crash bar to access the radiator area for intercooler mounting.
  4. Mount the intercooler using the provided brackets and hardware. Z1’s design uses a clean, factory-looking front-mount intercooler.
  5. Install the supercharger bracket and head unit on the engine’s accessory drive. The supercharger sits on the passenger side of the engine bay, driven by a dedicated belt from the crankshaft.
  6. Route the intercooler piping from the supercharger outlet to the throttle body, using silicone couplers and T-bolt clamps.
  7. Install the oil feed and drain lines – the supercharger requires an external oil supply from the engine’s oil pressure port.
  8. Replace spark plugs with a colder heat range (one step colder) to prevent pre-ignition under boost.
  9. Reinstall the bumper and all trim.
  10. Load the base tune from Z1’s provided Uprev or ECUTek file, then take the car to a dyno tuner for final calibration.

Most owners report the installation taking 8-15 hours depending on experience. Professional installation by a shop that specializes in Nissan/Z cars typically costs $1,000-$2,000.

Real-World Dyno Results

We compiled data from several public dyno sheets and forum threads to illustrate the range of results:

Configuration Fuel Boost (psi) Wheel Horsepower Wheel Torque (lb-ft)
Stage 1 + cat-back exhaust 93 octane 8 390 320
Stage 2 + test pipes + fuel pump 93 octane 11 430 350
Stage 2+ + E85 + full exhaust E85 14 478 385
Stage 2+ + built motor + race gas 110 octane 15 510 410

Note: These numbers are from various dynos (Dynojet, Dyno Dynamics, Mustang) and can vary by 5-10% depending on correction factors. Always compare before and after pulls on the same dyno for accurate gains.

Pros and Cons of the Z1 Supercharger

Advantages

  • Proven power gains – Z1 has sold thousands of kits with consistent results.
  • Good drivability – The centrifugal supercharger offers predictable power delivery; no sudden torque spikes like a roots blower.
  • Comprehensive kit – Includes all necessary hardware, injectors, and a base tune.
  • Intercooled – Air-to-air intercooling keeps intake temps manageable for street use.
  • Uprev/ECUTek tuning platform – Widely supported by tuners worldwide.

Disadvantages

  • Cost – The base kit starts around $5,500, and supporting mods quickly add another $2,000-$5,000.
  • Requires professional tuning – No turnkey plug-and-play solution; dyno time is mandatory.
  • No CARB EO (yet) – Not legal for emissions in California; street legality varies by state.
  • Oil supply system – The dedicated oil feed is more complex than some competitors that use self-contained oil reservoirs.
  • Limited top-end compared to turbos – Centrifugal superchargers often fall off slightly at the very top of the RPM range due to belt slip or gear reduction limits.

Reliability Considerations

The VQ37VHR engine is a stout platform, but adding 150+ horsepower introduces additional stress. Key reliability factors include:

  • Fueling – Running lean under boost will destroy pistons quickly. Use a wideband O2 sensor and monitor AFR during tuning.
  • Oil pressure – The supercharger oil feed draws from the engine’s oil system; ensure oil level is maintained and consider an oil pressure gauge.
  • Cooling system – At sustained high speeds or track use, temperatures can climb. A larger radiator and oil cooler are recommended for any 370Z with forced induction.
  • Drivetrain – Clutch, transmission, and differential should be in good condition. A 1.5-way limited-slip differential upgrade helps put the power down.
  • Maintenance intervals – Expect to change oil more frequently (every 3,000 miles or track day) and inspect spark plugs annually.

Many owners have accumulated 50,000+ miles on Z1 supercharged cars with no major issues – provided they kept up with maintenance and avoided detonation.

Alternatives to the Z1 Supercharger

While this article focuses on Z1 Motorsports, other forced induction options exist for the 370Z:

Stillen Supercharger

Stillen’s kit is very similar – centrifugal, intercooled, with comparable power levels. Priced slightly lower, but earlier versions lacked a proper oil pump feed (using a splash-feed system instead).

GTM / Forced Performance Turbo Kits

Twin-turbo and single-turbo kits are available from GTM, Forced Performance, and others. Turbos can produce similar power with potentially higher top-end, but they introduce lag and require significant fabrication for fitment.

Vortech / ProCharger Systems

These are universal supercharger heads that can be adapted, but Z1’s kit is purpose-built for the 370Z, making installation easier and fitment more refined.

For most street-driven 370Zs, the Z1 supercharger offers the best balance of power, reliability, and ease of installation.

Frequently Asked Questions

Can I install the Z1 supercharger on an automatic 370Z?

Yes. The kit fits both manual and 7-speed automatic transmissions. However, the automatic’s torque converter can be a limitation; many owners opt for a higher-stall converter or a transmission cooler.

Does the Z1 supercharger require engine internals?

For the base stage 1 (400 whp range), stock internals are generally safe with good tuning. For stage 2+ (450+ whp), upgrading to forged pistons and rods is strongly recommended for long-term peace of mind.

What tuning software do I need?

Z1 primarily supports Uprev (OSIRIS) and ECUTek. ECUTek offers more advanced features like flex-fuel sensor support, but both are capable. A custom dyno tune is required regardless.

Is the Z1 kit compatible with a Nismo 370Z?

Yes. It fits Nismo models without issue. Note that the Nismo has a different front bumper – intercooler fitment is still fine.

What is the expected lifespan of the supercharger head unit?

With proper oil changes (every 10,000 miles or annually), the gear-driven centrifugal head unit is very durable – many users report 100,000+ trouble-free miles.

Conclusion

The Z1 Motorsports supercharger kit is a proven, well-engineered solution for 370Z owners seeking substantial horsepower gains. In its base form, you can expect 380-400 wheel horsepower on pump gas – a gain of 100-120 hp over stock. With a larger intercooler, full exhaust, and E85 fuel, numbers exceeding 470 whp are achievable, translating to well over 500 crank horsepower. The key to success lies in proper installation, high-quality tuning, and supporting modifications – especially in the fuel system and cooling. When done correctly, a Z1 supercharged 370Z offers an exhilarating driving experience that rivals many high-end sports cars. Before making the leap, budget for professional installation and tuning, and consider the long-term reliability upgrades that come with higher power levels. For enthusiasts serious about unlocking the true potential of their 370Z, the Z1 supercharger is one of the most rewarding paths available.