Why the Right Brand Matters for Your VQ37VHR

The Nissan 370Z and its VQ37VHR engine have earned a loyal following among performance enthusiasts. With a high-revving 3.7-liter V6 that responds exceptionally well to bolt-on modifications, choosing the right aftermarket parts can mean the difference between a reliable daily driver and a track-ready machine. While there are dozens of brands claiming to boost horsepower, three names consistently stand out for their engineering quality, real-world results, and strong community support: Tomei, Stillen, and HKS. Each brand brings a distinct philosophy to the table, from all-out power to balanced street manners. In this expanded guide, we break down the best upgrades from each manufacturer, what makes them unique, and how to choose the right parts for your build.

Tomei Performance Upgrades

Tomei is a Japanese powerhouse known for its motorsport pedigree and obsessive attention to detail. Founded in 1968, the brand has supplied parts for everything from Super GT to grassroots time attack. For the 370Z and VQ37VHR, Tomei focuses on weight reduction, high-RPM power, and robust construction. Their parts are often the go-to choice for drivers who want to push the engine past 7,500 RPM without sacrificing reliability.

Exhaust Systems

Tomei's exhaust line is legendary among 370Z owners. The Tomei Expreme Ti Exhaust is a standout, constructed entirely from titanium to save weight while delivering a distinctive, aggressive tone. Unlike stainless steel alternatives, the titanium system reduces unsprung mass (roughly 10–12 pounds lighter than OEM) and improves throttle response. The dual-muffler design keeps drone to a minimum during cruising, yet opens up beautifully above 4,000 RPM. Many owners pair this with Tomei's test pipes or high-flow catalytic converters for maximum flow.

  • Tomei Expreme Ti Exhaust: Available in 60mm and 75mm piping diameters; the 75mm variant suits forced induction builds.
  • Tomei High-Flow Cats: Reduce exhaust restriction without triggering check engine lights when paired with a tune.
  • Tomei Y-Pipe: Replaces the restrictive factory Y-pipe for smoother exhaust flow.

Intake Manifolds and Plenums

The VQ37VHR’s factory intake plenum is a known bottleneck, especially at higher RPM. Tomei’s Type-S Intake Manifold addresses this with a larger plenum volume and short, equal-length runners. The result is improved top-end horsepower (typically 12–18 WHP gains when combined with a tune) without sacrificing low-end torque. The manifold is CNC-machined from billet aluminum and comes with a polished finish that looks stunning under the hood.

Engine Internals

For those building a dedicated track car or aiming for 500+ horsepower, Tomei offers camshafts and valvetrain components. Their Procams are designed for higher lift and duration, pushing peak power higher into the rev range. Combined with upgraded valve springs and retainers, these cams allow safe operation up to 8,000 RPM. While installation requires significant labor, the payoff is a screaming VQ that feels like a race engine.

  • Tomei Expreme Ti Exhaust (60mm and 75mm)
  • Tomei M7960 Turbo Kit (for track-only builds; requires careful tuning)
  • Tomei Type-S Intake Manifold
  • Tomei Procam Camshafts (256° and 264° durations)
  • Tomei Valve Spring & Retainer Kit

For more details, check out Tomei’s official site or retailers like Z1 Motorsports for application-specific fitment notes.

Stillen Performance Upgrades

Stillen (Stylin’ Concepts) has been an American aftermarket staple since 1985, with a strong focus on Nissan and Infiniti platforms. For the 370Z, Stillen is best known for its supercharger kits, but the brand also offers a comprehensive range of bolt-ons, suspension components, and aerodynamic parts. Stillen parts are designed for street-driven cars that see occasional track duty, striking a balance between power gains and daily drivability.

Supercharger Kits

The Stillen Supercharger Kit is arguably the most popular forced induction solution for the VQ37VHR. It uses a Vortech V3 centrifugal supercharger that produces linear, predictable power — unlike a turbo’s sudden surge, the supercharger builds boost smoothly from 2,500 RPM to redline. The kit includes a cast aluminum intake manifold, high-flow injectors, and an intercooler that fits behind the front bumper. With a standard tune, power jumps from the factory 332 HP to around 450–480 HP at the crank, depending on supporting mods. For more aggressive builds, Stillen offers a Stage 2 upgrade with a larger pulley and fuel system enhancements, pushing output past 550 HP.

  • Stillen Supercharger Kit Stage 1: 8 PSI boost, includes tune via Uprev or ECUTek.
  • Stillen Supercharger Kit Stage 2: 10 PSI boost, requires upgraded injectors and fuel pump.
  • Stillen Intercooler Upgrade: Optional larger core for sustained track sessions.

Body Kits and Aerodynamics

Stillen’s aero components are functional, not just cosmetic. Their Front Splitter is wind-tunnel tested to reduce front-end lift at speeds above 70 mph. The Rear Diffuser works with the factory underbody panels to smooth airflow. For a more aggressive look, Stillen offers side skirts and a carbon fiber rear spoiler. These parts are made from durable polyurethane or fibreglass, and most are direct bolt-on without requiring drilling.

Suspension Upgrades

Handling upgrades from Stillen focus on reducing body roll and improving steering response. Their Adjustable Coilovers feature 32-way damping and ride height adjustments, ideal for lowering the car 1–2 inches while maintaining comfort. Stillen also offers sway bars (front and rear) that are 20% stiffer than stock, and strut tower braces to stiffen the chassis. These upgrades are especially effective when paired with upgraded bushings and camber arms.

  • Stillen Supercharger Kit (Stage 1 or Stage 2)
  • Stillen Front Splitter
  • Stillen Adjustable Coilovers
  • Stillen Cat-Back Exhaust System
  • Stillen Cold Air Intake

Visit Stillen’s website for complete kit details and installation guides. Many enthusiasts also order through Concept Z Performance for competitive pricing and bundled packages.

HKS Performance Upgrades

HKS is synonymous with Japanese tuning culture. Founded in 1973, the brand has supplied parts for everything from drift machines to time attack monsters. For the 370Z, HKS offers a broad lineup that includes exhausts, turbo kits, oil coolers, and engine management. HKS parts lean toward the high-performance end of the spectrum, often requiring supporting modifications and professional tuning.

Exhaust Systems

The HKS Hi-Power Exhaust is a classic choice for the 370Z. It features a straight-through design with a large 90mm piping diameter, freeing up exhaust flow for significant gains (typically 10–15 WHP with a tune). The sound is deep and aggressive, with minimal drone thanks to HKS’s resonator design. The system is made from SUS304 stainless steel and includes a polished tip that resists corrosion. HKS also offers the Legamax and Silent Hi-Power variants for drivers who want a more subdued tone.

Turbo Kits

While Stillen dominates superchargers, HKS is the go-to for turbocharging the VQ37VHR. The HKS GT Turbo Kit uses a Garrett GT2860RS (or larger GT3076R for higher power) and includes a cast iron manifold, wastegate, blow-off valve, and intercooler piping. The system is designed for reliability, with a water-cooled center cartridge that extends turbo life. Power output ranges from 400–600 HP depending on boost level and fuel system upgrades. Unlike centrifugal superchargers, the HKS turbo delivers punchy mid-range torque and a surge of power at higher RPM.

However, installation is more complex, and heat management (wrapping exhaust components, adding oil coolers) is critical.

ECU Tuning and Electronics

To unlock the full potential of any forced induction setup, HKS offers the F-Con V Pro standalone ECU. This unit replaces the factory ECU and gives tuners full control over fuel, ignition, boost, and timing maps. It also includes data logging capabilities and supports real-time tuning. While the F-Con V Pro is a powerful tool, it requires a skilled tuner familiar with the VQ37VHR platform. For milder builds, HKS offers the F-CON iS, a piggyback unit that works with the factory ECU for basic fuel and timing adjustments.

Engine and Drivetrain Support

HKS also produces reliability-focused parts for the 370Z. Their Oil Cooler Kit is essential for track use, dramatically reducing oil temperatures that can exceed 260°F during hard driving. The HKS Oil Filter uses a high-flow filtration media for better protection at high RPM. For those pushing high horsepower, HKS offers a sequential blow-off valve and fuel pressure regulator to maintain consistent fuel delivery.

  • HKS Hi-Power Exhaust System
  • HKS GT Turbo Kit (GT2860RS or GT3076R)
  • HKS F-Con V Pro ECU
  • HKS Oil Cooler Kit
  • HKS Super SQV Blow-Off Valve

Check HKS’s global site or specialized retailers like Import Image Racing for fitment and availability.

Choosing the Right Brand for Your Build

With three excellent options, the decision often comes down to your goals and budget:

  • Tomei: Best for weight reduction, high-RPM power, and naturally aspirated builds. Ideal for track-focused cars that value responsiveness and reliability over brute force.
  • Stillen: The king of supercharging for the VQ37VHR. Best for street-driven cars seeking substantial, linear power gains without sacrificing daily usability. Their aero and suspension parts are also top-tier.
  • HKS: The choice for turbo enthusiasts who want maximum power potential and are willing to invest in supporting mods (fuel systems, engine management, cooling). HKS exhausts and oil coolers are great standalone upgrades.

Installation and Tuning Considerations

While many bolt-on parts (exhausts, intakes, coilovers) can be installed at home with basic tools, supercharger and turbo kits require professional installation. The VQ37VHR’s engine bay is tight, and routing intercooler piping or turbo heat shields is not a beginner job. Additionally, any part that significantly increases airflow (intake, exhaust, forced induction) will require ECU tuning to avoid a rich or lean condition. Brands like Tomei, Stillen, and HKS often partner with tuning software providers like Uprev or ECUTek. Always factor in the cost of a dyno tune ($400–$800) when budgeting for performance parts.

Conclusion

The Nissan 370Z’s VQ37VHR engine is a rewarding platform to modify, and Tomei, Stillen, and HKS represent the gold standard in aftermarket support. Whether you’re chasing lap times, highway pulls, or simply a more engaging driving experience, each brand offers unique strengths. Tomei delivers race-bred engineering for the purist, Stillen provides balanced kits for the street, and HKS unlocks extreme power for the dedicated enthusiast. By choosing quality parts from these manufacturers and investing in proper tuning, you can transform your 370Z into a machine that truly performs as good as it looks.