High-Performance VQ37 Builds: Integrating Custom Camshafts and Aftermarket Pistons for 600+ HP

The VQ37 engine, a naturally aspirated 3.7-liter V6 produced by Nissan, has long been celebrated for its smooth power delivery, high-revving character, and surprising resilience. Found in the Nissan 370Z, Infiniti G37, and Q50/Q60, this powerplant offers a robust foundation for serious horsepower. With the correct modifications, including custom camshafts, aftermarket pistons, and a suite of supporting upgrades, the VQ37 can reliably surpass the 600-horsepower mark. This article provides a detailed roadmap for achieving that level of performance, covering component selection, engine preparation, tuning, and reliability considerations.

While factory VQ37s produce around 330-350 horsepower, the architecture is capable of much more. The aluminum block, forged steel crank, and six-bolt main caps provide a sturdy base. However, to double the output, every internal and external component must be carefully chosen to work as a system. Below we break down the essential elements of a 600+ hp VQ37 build.

Foundation: The VQ37 Short Block

The short block is the heart of any high-performance build. For 600+ horsepower, the factory short block must be comprehensively upgraded. While the stock VQ37 block can handle moderate power increases, sustained boost or high-rpm naturally aspirated builds require a reinforced bottom end.

Block Preparation

Start with a clean, inspected block. Many builders opt to:

  • Deck the block for a perfectly flat sealing surface.
  • Hone the cylinders to the correct crosshatch pattern, often using a torque plate to mimic head bolt distortion.
  • Install billet main caps for additional crankshaft stability, especially under high boost or high RPM.
  • O-ring the block or use a multi-layer steel (MLS) gasket with improved clamping force to prevent head lift.

Crankshaft and Bearings

The factory VQ37 forged steel crankshaft is generally adequate for 600 hp, but it should be carefully inspected. Most builders send the crank out for:

  • Micro-polishing of the journals to reduce friction.
  • Balancing with the flywheel and harmonic damper to eliminate vibrations at high revs.
  • Installation of high-performance bearings such as ACL Race or Clevite tri-metal bearings, which offer better oil film retention and load capacity.

Connecting Rods

Stock VQ37 connecting rods are cast and become a weak point above ~550 hp. For a 600+ hp build, aftermarket forged rods are mandatory. Popular choices include:

  • Carillo rods – extremely strong, often used in 800+ hp builds.
  • Manley H-beam or I-beam rods – excellent value and strength.
  • K1 Technologies rods – widely used in the 370Z community.

Choose rods with a bolt upgrade to ARP 2000 or L19 fasteners for added safety.

Aftermarket Pistons: The Key to Higher Compression and Power

Aftermarket pistons are essential for three primary reasons: increasing compression ratio, improving strength, and reducing weight. The factory pistons are cast with a high silicon content, making them brittle at extreme power levels.

Piston Material

Two main piston materials dominate VQ37 builds:

  • Forged 2618 aluminum – softer and more ductile, ideal for high-boost applications. These expand more when hot, requiring slightly larger piston-to-wall clearance. They resist cracking better than other alloys.
  • Forged 4032 aluminum – lower expansion, can run tighter clearances, and has better wear resistance. Good for naturally aspirated and mild boost builds up to ~600 hp.

For a 600+ hp target, particularly with forced induction, 2618 alloy is the recommended choice.

Compression Ratio and Piston Design

Select piston compression ratio based on your induction method:

  • Naturally Aspirated – aim for 12.0:1 to 13.0:1 compression with aggressive camshafts and high-octane fuel. This requires a flat-top or slight dome piston.
  • Single Turbo or Supercharged – 9.5:1 to 10.5:1 compression is typical to manage cylinder pressure. Use a dished piston design to lower compression and reduce detonation risk.
  • Twin Turbo – similar to single turbo, though some builders go as low as 9.0:1 for very high boost (25+ psi).

Piston manufacturers like Wiseco, JE, CP-Carrillo, and Diamond offer custom piston sets for the VQ37. Work with a reputable builder to spec the right bore size, compression height, and ring package.

Piston Rings

Ring choice affects both power and oil control. For high-horsepower VQ37 builds:

  • Stainless steel top ring with a 1.2mm or 1.5mm thickness – the thinner ring reduces friction and allows faster ring movement.
  • Napier or low-tension second ring – helps with oil control without excessive drag.
  • Three-piece oil ring – standard, but ensure proper tension for your power level.

Gapping rings for boost is critical: typical top ring gap for NA is 0.004-0.005" per inch of bore; for boost, increase to 0.005-0.006" to accommodate thermal expansion and prevent ring butting.

Custom Camshafts: Breath of Fire

Camshaft selection is arguably the single most impactful modification for naturally aspirated VQ37 builds, and it remains important for forced induction. Custom camshafts optimize valve timing to move the power curve higher in the RPM range while retaining low-end drivability.

Understanding Camshaft Specifications

  • Duration (measured at 0.050" lift) – longer duration pushes the power peak higher. For 600+ hp NA, durations of 240-260 degrees intake and exhaust are common. For boost, slightly shorter durations (220-240) can produce excellent mid-range torque.
  • Lift – higher lift opens the valve more, improving airflow. However, excessive lift requires stronger valve springs and may cause valve-to-piston clearance issues. Typical lift for VQ37 builds ranges from 0.380" to 0.430".
  • Lobe separation angle (LSA) – 110-114 degrees is common. Narrower LSA (e.g., 108) increases overlap, which helps top-end power at the cost of idle quality and vacuum. Wider LSA (112-114) improves idle and low-rpm manners.

Custom camshafts from companies like JG Engine Dynamics, Cam Motion, and Brian Tooley Racing can be ground to your exact specs. Always discuss your intended use (street/strip/track) and supporting modifications with the cam grinder.

Valvetrain Upgrades for Aggressive Cams

Aggressive cam profiles demand stronger valvetrain components:

  • Dual or beehive valve springs rated for your cam's lift and RPM target (8,000+ RPM common).
  • Hardened steel retainers and titanium retainers – titanium reduces reciprocating mass.
  • Chrome-moly pushrods (if converting to adjustable rockers) or upgraded rocker arms for VQ37 (stock rockers can fail under extreme spring pressures).
  • Upgraded valve guides and seals to handle the higher spring pressures and increased temperatures.

Some builders also convert the VQ37 to a solid lifter setup for more aggressive ramp rates, though this increases maintenance.

Supporting Modifications for 600+ HP

Without proper support, even the best internal components will be choked. The following systems must be upgraded to achieve and sustain 600+ horsepower.

Fuel System

At 600 hp, a stock VQ37 fuel system is completely insufficient. Requirements:

  • Fuel injectors – minimum 1000cc/min for naturally aspirated; 1300-1500cc/min for boost. Use high-impedance, modern injectors from Injector Dynamics, Bosch, or FIC.
  • Fuel pump(s) – in-tank pump such as Walbro 525 or AEM 340LPH E85-compatible. For E85 or above 650 hp, a dual-pump setup or external boost-referenced pump is recommended.
  • Fuel lines and rails – upgrade to -6AN (or -8AN for return-style) with a fuel pressure regulator.
  • Flex fuel capability – if running E85, include a flex fuel sensor for ECU tuning.

Intake and Exhaust

The VQ37 responds well to free-flowing induction and exhaust. Key parts:

  • Cold air intake (CAI) – short ram or long tube designs from Stillen, Z1 Motorsports, or custom fabrication.
  • Throttle bodies – twin stock throttle bodies are often retained; aftermarket 75mm+ units can be fitted with adapters.
  • Intake manifold – the factory manifold is decent up to 500 hp, but a long-runner manifold (like the MBo 1000) or a sheet metal intake can gain 20-30 hp at high RPM.
  • Exhaust headers – long-tube headers (e.g., PPE Engineering, Stillen) improve scavenging. For forced induction, use log-style manifolds or shorties.
  • Exhaust system – 3-inch test pipes or high-flow cats into a 3-inch catback. Avoid excessive backpressure; a single 3.5-inch or dual 2.5-inch system works well.

ECU Tuning

Tuning a 600+ hp VQ37 requires either a reflashed stock ECU (via UpRev or ECUTEK) or a standalone ECU like Haltech, MoTeC, or AEM Infinity. Standalone ECUs offer limitless adjustability but require professional calibration. Important tuning considerations:

  • Air/fuel ratio – target 12.5:1 for naturally aspirated on gasoline; 11.5-12.0:1 for boosted; 7.5-8.0:1 for E85.
  • Ignition timing – must be carefully calibrated to avoid detonation, especially with high compression or boost.
  • Cam timing (VVEL) – VQ37s use variable valve event and lift (VVEL). Retuning VVEL maps is essential for camshaft upgrades. Many tuners disable VVEL and run fixed lift for simplicity.
  • Fail-safes – enable knock detection, boost cut, and fuel pressure monitoring in the tune.

Reliability and Maintenance

Building a 600+ hp VQ37 is about engineering longevity, not just peak numbers. Consider these reliability upgrades:

Oil System

  • Oil cooler – a 25-34 row Setrab or Earl's cooler with thermostat is essential for track use.
  • Oil pump – the factory oil pump can fail under high RPM. Replace with a boundy or billet oil pump gear or a high-volume pump from Tomei or Boundary.
  • Baffled oil pan – prevents oil starvation during hard cornering or acceleration. Options from Ivey, CZP, or custom fabrication.
  • Accusump – adds an oil reserve for starts, preventing dry starts on track.

Cooling System

  • Upgraded radiator – a full aluminum radiator (e.g., CSF, Griffin) with dual electric fans.
  • Water pump – ensure it is in good condition; some use an electric water pump for better flow control.
  • Intercooler (if boosted) – size appropriately for your turbo selection. An air-to-air bar-and-plate core is common.

Drivetrain

600 hp will overwhelm the factory driveline. At minimum, upgrade to:

  • Stronger clutch or torque converter – a twin-disc clutch or high-stall converter.
  • Differential – install a limited-slip differential with upgraded axles.
  • Transmission – the CD009 6-speed can hold 600 hp with careful driving, but many swap to a built automatic (e.g., 4L80E) for consistency.

Putting It All Together: Example Build Spec

Here is a sample parts list for a 600+ hp turbo VQ37 build:

  • Block: decked, bored 0.020", billet main caps
  • Pistons: Wiseco 2618 9.5:1, 0.060" overbore
  • Rods: Manley H-beam with ARP 2000 bolts
  • Crank: factory, micro-polished and balanced
  • Cams: custom grind, 230/230 duration, 0.400" lift, 112 LSA
  • Heads: ported, oversized valves, dual valve springs
  • Turbo: Garrett G35-1050, 76mm inducer (single)
  • Fuel: ID1700 injectors, Walbro 525 pump, -8AN fuel system
  • Tuning: Haltech Elite 2500
  • Drivetrain: twin-disc clutch, DVD axles, OS Giken diff

A build like this, with proper tuning, will produce 600-700 hp at the wheels reliably for street use, with occasional track days.

External Resources and Further Reading

For more details on VQ37 performance, consult these resources:

Building a high-performance VQ37 is a rewarding undertaking. By carefully selecting custom camshafts, aftermarket pistons, and all supporting modifications, you can create a 600+ horsepower powerhouse that remains driveable and durable. Plan thoroughly, invest in quality components, and work with experienced tuners to achieve the best results.