Infiniti G37: Engine Specs & Turbo Upgrades

Infiniti G37: Unveiling the Heart of the Machine

The Infiniti G37, a nameplate synonymous with performance and luxury, has captivated automotive enthusiasts since its debut. As a pivotal model in Infiniti's G-series lineage, which traces its roots back to the iconic Nissan Skyline, the G37 has consistently delivered a thrilling driving experience. Launched in 2008 as part of the fourth generation, it succeeded the G35, inheriting a legacy of refined engineering. While the G-series also featured other engine designations like the G25 and G35, the G37 carved out its own identity, primarily through its potent powertrain. Available in elegant sedan, sporty coupe, and sophisticated convertible body styles, the G37's nomenclature remained consistent, focusing on the core mechanical prowess that defined it. The initial iterations of the 3.7-litre V6 engine that powered the G37 were already impressive, producing around 330 horsepower. However, Infiniti's commitment to refinement saw this engine evolve, with later models boasting an enhanced output of 348 horsepower, all from the same robust 3.7-litre displacement. This dedication to performance ensures that the G37 continues to be a desirable vehicle, even as newer models emerge.

G37 Wheel Specifications: A Closer Look

Beyond its formidable engine, the Infiniti G37's aesthetic appeal and dynamic capabilities are also significantly influenced by its wheel selection. The majority of G37 models were equipped with either 18-inch or 19-inch alloy rims, contributing to both a commanding presence and responsive handling. A notable exception was a specific 17-inch alloy wheel variant, distinguished by its silver finish and a distinctive five-spoke design featuring triple spokes. The broader range of alloy wheels offered a variety of finishes, catering to diverse tastes. These included shades of light hyper silver, hyper silver, medium silver, classic silver, bright silver, and a sophisticated graphite. Adding a touch of premium flair, one particular 18-inch alloy rim was presented with a striking chrome finish and a five double-spoke configuration. A clever design choice for many of these wheels involved offering different specifications for the front and rear axles. This staggered setup is not merely for visual appeal; it is a deliberate engineering decision aimed at optimising traction and enabling higher speeds, particularly during spirited driving or cornering.

Elevating G37 Performance: The Turbocharged Path

For the discerning G37 owner who craves even more exhilarating performance, the prospect of forced induction, specifically turbocharging, presents an irresistible upgrade. While naturally aspirated bolt-on modifications can offer incremental improvements, they often fall short of the transformative power that a well-executed turbo system can deliver. Turbo builds, although potentially a more significant investment, are widely regarded as the most impactful method for extracting substantial power from the G37's VQ37VHR engine. The key to unlocking this potential lies in ensuring the build is performed with meticulous attention to detail and technical expertise. This article will delve into the intricacies of turbocharging the G37, providing insights into some of the premier turbo kits available on the market.

The VQ37VHR Engine: A Turbocharger's Dream

The G37's VQ37VHR engine represents a significant advancement over the VQ35HR found in its predecessor, the G35. This larger displacement engine not only produces more horsepower and torque but also serves as an exceptional platform for turbocharging. Despite its increased complexity compared to earlier VQ iterations, the VQ37VHR maintains a reputation for robust reliability, often likened to a "hammer" in its dependability. This inherent strength makes it exceptionally receptive to forced induction. In its naturally aspirated form, the VQ37VHR is capable of handling up to 500 wheel horsepower (whp) on its stock internal components. For those aiming to preserve long-term reliability, capping the power output at around 450 whp is a prudent strategy, ensuring the engine's longevity for many years. Pushing beyond the 500 whp mark necessitates more extensive internal engine modifications, with forged connecting rods and pistons being the primary areas to address as they represent the weakest points in the stock engine assembly.

Essential Supporting Upgrades for Turbocharging

Regardless of your targeted power output, several supporting modifications are crucial when turbocharging the G37. These ensure the engine can safely and effectively utilise the increased airflow and fuel delivery:

• Upgraded Fuel System: This is paramount and typically involves a higher-capacity fuel pump, larger fuel injectors, reinforced fuel rails, and a reliable fuel pressure regulator to meet the increased fuel demands.
• Engine Management System: A sophisticated engine management system, often an ECU reflash or a standalone unit, is vital for optimising ignition timing, fuel mapping, and boost control to safely harness the turbocharger's potential.
• Upgraded Exhaust System: A less restrictive exhaust system, including performance downpipes and cat-back exhausts, is necessary to efficiently expel exhaust gases and minimise backpressure, allowing the turbocharger to spool more effectively.

Transmission Considerations for Turbocharged G37s

One of the noteworthy advantages of turbocharging the G37 is the resilience of its stock transmission. The JK41A transmission, equipped in the G37, is a highly reliable unit within Infiniti's lineup and is generally capable of withstanding the power increases associated with moderate turbo upgrades without the need for a transmission swap. This simplifies the overall build process and cost.

Twin Turbo vs. Single Turbo: A Strategic Choice

When embarking on a turbocharging project for the G37, a key decision involves selecting between a twin-turbo or a single-turbo setup. Turbochargers function by harnessing the engine's exhaust gases to spin a turbine, which in turn compresses incoming air. This process inevitably leads to a phenomenon known as turbo lag – a delay between pressing the accelerator and the turbo delivering its full boost.

Twin Turbo Kits: Minimising Lag, Maximising Mid-Range

Twin-turbo systems typically employ two smaller turbochargers instead of a single, larger unit. This configuration significantly reduces turbo lag, as the smaller turbines require less exhaust gas volume to reach their optimal operating speed. The power delivery from twin-turbo setups is often characterised by a strong surge in the mid-range RPMs, with power tapering off as the engine approaches its redline. This powerband is particularly well-suited for applications like autocross, time attack, drifting, and even general daily driving, where responsiveness across a broad RPM range is desirable. While twin-turbo kits may carry a slightly higher price tag than comparable single-turbo systems, the enhanced driving experience they offer is often considered well worth the investment.

Featured Twin Turbo Kits for the Infiniti G37:

Single Turbo Kits: Raw Power, Top-End Focus

Single-turbo systems, while often associated with more pronounced turbo lag, excel at delivering substantial power, particularly in the upper RPM range. This characteristic makes them ideally suited for drag racing and track-focused driving where sustained high-speed operation is common. While the popularity of single-turbo setups for the VQ37VHR has waned in favour of twin-turbo configurations, driven by market demand and manufacturer focus, dedicated enthusiasts can still find high-quality single-turbo kits.

Notable Single Turbo Kits for the Infiniti G37:

• Soho Motorsports: Known for its top-mounted configuration, this kit utilises a Garrett GTX3582R Reverse Rotation turbo. The "reverse rotation" is a space-saving design that optimises piping layout in the engine bay. Constructed with T304 stainless steel piping to minimise heat absorption, it offers options for different performance stages and can retain the stock exhaust manifold. Stage two kits have demonstrated figures around 500-570 rwhp with appropriate boost levels.
• S&R Performance: This kit prioritises simplicity and reliability, featuring a Precision 62mm turbo. It is highly regarded for its ease of installation and has been known to push well over 600 whp on stock blocks, though such extreme power levels require expert tuning and are not recommended without significant experience. The turbo's high mounting position allows for gravity-fed oil return, simplifying the plumbing.

Which Turbo Kit is Right for You?

The choice between a single and twin turbo setup for your G37 hinges on your individual driving preferences and performance objectives. Twin-turbo systems generally offer a more immediate and linear power delivery, making them a favourable choice for daily drivability and a broader range of performance applications. Their powerband is often more accessible for everyday driving scenarios. In terms of overall value and driving experience, twin-turbo kits are frequently recommended. The AAM Competition kit, in particular, stands out for its proven reliability and widespread adoption by G37 owners as a daily driver modification, earning it a reputation as arguably the best all-around G37 turbo kit available.

Frequently Asked Questions

What engine is in the Infiniti G37?

The Infiniti G37 is powered by a 3.7-litre V6 engine, known internally as the VQ37VHR.

How much horsepower does the stock G37 engine produce?

Early models produced around 330 horsepower, with later models seeing an increase to approximately 348 horsepower.

Can the G37 engine handle turbocharging?

Yes, the VQ37VHR engine is considered very robust and turbo-friendly. It can reliably handle up to approximately 450-500 wheel horsepower on stock internals with proper supporting modifications and tuning.

What are the main differences between twin-turbo and single-turbo kits for the G37?

Twin-turbo kits generally offer reduced turbo lag and a broader powerband, ideal for daily driving and spirited use. Single-turbo kits typically provide more power in the top-end RPM range, favouring drag racing and track use, but can have more noticeable lag.

Do I need to upgrade the transmission when turbocharging a G37?

For moderate power increases (up to around 500 whp), the stock JK41A transmission in the G37 is generally considered strong enough. For significantly higher power levels, transmission upgrades may become necessary.

Choosing to enhance your Infiniti G37 with a turbocharger is a significant undertaking that promises a dramatic uplift in performance. By understanding the nuances of twin-turbo versus single-turbo systems and the essential supporting modifications, G37 owners can make informed decisions to achieve their desired power goals while maintaining the car's renowned reliability. Whether you opt for the immediate response of a twin-turbo setup or the raw top-end power of a single turbo, the VQ37VHR engine is a capable platform ready to be unleashed.

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