Nissan VQ37VHR: The VVEL-Equipped Evolution of the Legendary VQ V6
The VQ37VHR is the mid-2000s update to Nissan's VQ V6 architecture. Introduced in 2007, it added **VVEL** (Variable Valve Event and Lift) — a continuously variable valve lift system — to the proven VQ35DE platform. The result was a 3.7-liter V6 making 332 HP in the 370Z Z34 witho
Nissan VQ37VHR: The VVEL-Equipped Evolution of the Legendary VQ V6
The VQ37VHR is the mid-2000s update to Nissan's VQ V6 architecture. Introduced in 2007, it added VVEL (Variable Valve Event and Lift) — a continuously variable valve lift system — to the proven VQ35DE platform. The result was a 3.7-liter V6 making 332 HP in the 370Z Z34 without turbocharging, proving Nissan could extract F1-style specific output from a naturally-aspirated production V6.
Factory Specifications
| Spec | Value |
|---|---|
| Displacement | 3,696 cc (226 cu in) |
| Configuration | 60° V6, longitudinal, RWD (370Z) |
| Bore × Stroke | 95.5 mm × 86.0 mm |
| Compression Ratio | 11.0:1 |
| Block Material | Aluminum with iron liners |
| Head Material | Aluminum alloy, DOHC 24-valve |
| Valvetrain | DOHC 24-valve, CVTCS (variable timing) + VVEL (variable lift) |
| Aspiration | Naturally aspirated |
| Fuel System | Sequential multi-port EFI with tumble valves |
| Factory Power | 332 HP @ 7,000 rpm (370Z) |
| Factory Torque | 270 lb-ft (366 Nm) @ 5,200 rpm |
| Redline | 7,500 rpm |
| Oil Capacity | 5.1 L |
VVEL: Variable Valve Event and Lift
The defining innovation of the VQ37VHR is VVEL — a mechanical valve lift adjustment system similar in concept to BMW's Valvetronic. Unlike simple cam-lobe switching (Honda VTEC) or cam phasing (Toyota VVT-i), VVEL continuously varies intake valve lift and duration across the entire rev range.
The system works via a complex rocker arm assembly on the intake side. An eccentric driver shaft changes the effective lever ratio between the cam lobe and the valve, continuously varying lift from about 2.3 mm (minimum at idle) to 10.6 mm (maximum at WOT high RPM). Duration changes correspondingly from ~110° to ~250°.
Benefits:
- No throttle plate control needed at part throttle — the intake valve lift itself determines air intake, eliminating pumping losses
- Better low-RPM torque than simple variable timing
- Higher peak power from aggressive WOT lift profiles
- Improved fuel economy at part throttle
The complexity adds cost and has been a reliability issue on some high-mileage examples.
Known Weaknesses
1. VVEL Ladder Assembly Failure (2009-2011)
The VVEL mechanism sits in a "ladder" assembly on top of the cylinder head. Early production VQ37VHR engines (2009-2011) had quality control issues with the ladder, causing ticking noises and eventually check engine lights with codes P0011 or P0021. Nissan issued TSB coverage for some affected vehicles.
The fix is replacing the entire VVEL ladder assembly — an expensive repair ($1,500-$2,500 out of warranty). This is the primary reliability concern with the VQ37VHR.
2. Valve Timing Solenoid Wear
CVTCS solenoids can stick or clog with high-mileage oil sludge.
3. Rear Main Seal (Same as VQ35DE)
Inherited from the VQ platform.
4. Radiator Plastic End Tanks
Same issue as 350Z — plastic tanks crack after 10+ years.
Real Tuning Limits
| Configuration | Safe RWHP | Notes |
|---|---|---|
| Stock 370Z | 290-310 HP | RWD drivetrain loss |
| Bolt-ons + tune | 315-340 HP | Modest NA gains |
| Supercharger (Vortech, Stillen) | 450-520 HP | Common FI upgrade |
| Twin-turbo custom | 600-800 HP | Rare builds |
The VVEL system limits aftermarket cam swap options — you can't simply swap in aggressive cams because VVEL interferes with the lift profile. This makes the VQ37VHR less tuner-friendly than the simpler VQ35DE.
Famous Applications
Nissan 370Z Z34 (2009-2020) — The primary sports car application. 332 HP, 6-speed manual with SynchroRev Match, optional Nismo variant with 350 HP.
Infiniti G37 Coupe / Convertible (2008-2013) — Luxury coupe with VQ37VHR.
Infiniti Q50 3.7 — Early Q50 sedans got VQ37VHR before switching to VR30DDTT in 2016.
Infiniti Q60 — Q50's coupe counterpart.
Infiniti QX50/QX70 SUV — SUV application.
Factory Service Data
- Oil Change: 5,000 mi (8,000 km)
- Spark Plugs: NGK PLFR5A-11
- Timing Chain: Chain-driven
- Coolant: Nissan LLC Blue
Conclusion
The VQ37VHR is an evolutionary refinement of the VQ35DE with modern variable valve lift technology. It makes more power (332 vs 287/306 HP) with comparable fuel economy. It's the engine that kept the Z-car competitive through 2020. But VVEL adds complexity and reliability concerns that the simpler VQ35DE didn't have. For tuners, the VQ35DE is easier. For stock drivers, the VQ37VHR is better. Both will be remembered as the V6 engines that powered Japanese sports cars through the 2010s.
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