Building and Maintaining a 2008 Infiniti G35 Custom: Modifications, Performance, and Upgrades

The 2008 Infiniti G35 remains a popular platform for automotive enthusiasts seeking a rear-wheel-drive sports sedan with a high-revving VQ35HR V6 engine, offering an ideal balance of luxury, everyday usability, and aftermarket customization potential.

The 2008 Infiniti G35 represents a sweet spot in Japanese luxury-performance history. Sitting on Nissan's legendary FM (Front Midship) platform, it bridges the gap between executive comfort and track-capable dynamics. Because the platform shares its architectural DNA with the iconic Nissan 350Z, the aftermarket support for a 2008 Infiniti G35 custom build is vast. Whether you are looking to enhance the aggressive lines of the Journey or Sport trims, extract more horsepower from the dual-throttle-body VQ35HR engine, or dial in the suspension geometry for canyon carving and drift events, this platform rewards thoughtful, well-executed modifications.

Understanding the unique characteristics of the 2008 model year is essential before turning a single wrench. Unlike the earlier 2003–2006 G35 sedans which used the VQ35DE engine, the 2007 and 2008 models received the heavily revised VQ35HR (High Revolution) engine. Featuring a taller redline (7,500 RPM), dual air intakes, a stiffer block, and dual variable valve timing (e-VVT on intake, hydraulic on exhaust), the HR motor responds differently to modifications than its predecessor. Tailoring a custom build to respect these mechanical nuances ensures long-term reliability while achieving your performance and aesthetic goals.

Understanding the VQ35HR Platform and Customization Goals

Before purchasing aftermarket parts or visiting a fabrication shop, defining a clear vision for your 2008 Infiniti G35 custom project prevents wasted time and money. The car can be pulled in several distinct directions: a daily-driven VIP cruiser, a weekend autocross and track toy, or a clean stance build. Each path requires a different hierarchy of upgrades.

The VQ35HR engine bay is famously tight, particularly around the dual intake plenums and exhaust manifolds. Recognizing these spatial constraints helps owners avoid parts that promise massive gains but cause fitment headaches. Furthermore, establishing a budget that accounts for supporting modifications—such as upgraded cooling for track use or stiffer bushings when lowering the chassis—ensures the build remains cohesive.

Trim Levels and Factory Foundations

The 2008 lineup primarily features the Base, Journey, and Sport (S) trims. For an enthusiast custom build, starting with the Sport trim or retrofitting Sport components is ideal. The Sport package includes:

• 14.7:1 quick-ratio steering gear
• Sport-tuned suspension dampers and springs
• Larger 14-inch front and 13-inch rear brakes with 4-piston front and 2-piston rear calipers
• Unique 18-inch split-spoke wheels
• Bolstered sport seats and paddle shifters (on automatic models)

If you start with a Base or Journey model, upgrading the braking system and suspension should take priority over cosmetic additions to match the safety and dynamic capability of a true performance build.

Engine Performance Upgrades: Breathing and Tuning

The VQ35HR is an incredible canvas for naturally aspirated power, but extracting gains requires addressing factory bottlenecks in the intake and exhaust systems.

Air Intake Systems

Because the VQ35HR utilizes dual throttle bodies and dual intake tubes, single cold-air intakes are generally ineffective compared to dual-filter setups. High-quality dual short-ram intakes or true cold-air setups that position the filters behind the front bumper can yield noticeable mid-range and top-end power gains, accompanied by an aggressive induction roar. When selecting intakes, ensure the mass air flow (MAF) sensor housings maintain the correct internal diameter to prevent lean or rich running conditions that trigger check engine lights.

Exhaust Modifications

The factory exhaust on the G35 sedan is heavily muffled, prioritizing quiet refinement over sound and flow. Upgrading the exhaust requires careful consideration of the dreaded "VQ drone"—a resonant buzzing sound between 2,000 and 3,000 RPM common with poorly designed aftermarket cat-back systems.

• Cat-Back Exhausts: Look for systems featuring Helmholtz resonators or true X-pipes (such as those from Fast Intentions or Motordyne) to smooth out the exhaust note and eliminate drone.
• Test Pipes and High-Flow Cats: Replacing factory catalytic converters with high-flow cats or test pipes significantly increases exhaust flow and rasp. Note that test pipes will cause the vehicle to fail tailpipe emissions testing and may trigger an O2 sensor code unless tuned out.

Engine Tuning

Unlike older vehicles where ECU tunes were optional, any significant modification to the intake or exhaust on a 2008 G35 benefits immensely from a custom dyno tune. Upgrades like the UpRev Osiris or ECUTEK software allow tuners to adjust air-fuel ratios, optimize ignition timing for higher-octane fuel, raise the rev limiter slightly, and recalibrate throttle response curves for a sharper pedal feel.

Suspension and Handling Modifications

The FM platform boasts a front mid-ship engine layout with a near-50/50 weight distribution, making it an exceptional handling chassis. Customizing the suspension can transform the car from a comfortable cruiser into a precision cornering machine.

Coilover Systems vs. Lowering Springs

Simply slapping lowering springs onto factory struts is a common mistake that blows out aging dampers and ruins ride quality. Investing in a quality set of single- or double-adjustable coilovers (such as BC Racing, Fortune Auto, or KW) allows you to dial in ride height, spring rates, and damping characteristics.

Suspension Geometry and Bushings

When you lower a 2008 Infiniti G35, the multi-link suspension geometry changes, causing extreme negative camber and toe-in. This leads to premature inner tire wear and twitchy high-speed stability. A complete custom suspension refresh should include:

• Front upper adjustable control arms (to correct camber and caster)
• Rear camber arms and toe bolts/rods
• Whiteline or Energy Suspension polyurethane bushings to replace worn-out factory rubber, tightening up steering feedback and eliminating slop in the subframe.

Exterior Styling and Aerodynamics

A custom exterior on a G35 sedan requires a delicate touch to avoid looking overdone. Because the sedan shares styling cues with contemporary Infiniti luxury models, subtle enhancements yield the best aesthetic results.

Front Bumpers and Splitters

Many owners opt for an IPL (Infiniti Performance Line) style front bumper or an aftermarket lip spoiler to give the front fascia a more aggressive, lower-slung appearance. Carbon fiber splitters add a motorsport-inspired look, but ground clearance must be monitored closely if the car is lowered.

Wheels and Fitment

Wheels dictate the entire stance of the vehicle. The G35 sedan has generous wheel wells, but aggressive offsets are required to sit flush with the fenders.

• Square vs. Staggered: While a staggered setup (wider wheels in the rear) maintains factory handling dynamics, a square setup allows for tire rotation and neutralizes understeer.
• Common Specs: Popular custom wheel configurations range from 18x9.5 to 19x10.5 with offsets between +15 and +22, often requiring a mild fender roll if running wider rubber.

Interior Upgrades and Modern Technology

The cabin of a 2008 Infiniti G35 features hallmark 2000s Japanese luxury materials, complete with aluminum trim and analog clocks. However, the factory infotainment system is severely outdated by modern standards.

Infotainment Upgrades

Upgrading the center stack is one of the most practical modifications you can perform. Because the HVAC controls are integrated into the factory radio bezel on non-navigation models, replacing the head unit requires specialized dash kits such as those from Metra or JDM double-din finishers. Installing a modern Android Auto or Apple CarPlay head unit breathes new life into the interior, providing hands-free calling, reliable navigation, and modern audio streaming.

Steering Wheels and Seating

For track-focused builds, replacing the heavy factory steering wheel with a quick-release setup and a deep-dish wheel (like a Nardi or Personal) improves driver engagement. For street builds, wrapping the factory steering wheel in fresh perforated leather or Alcantara preserves factory airbag functionality while upgrading tactile comfort.

Common Issues and Maintenance Before Customizing

Modifying a high-mileage or neglected engine will only accelerate mechanical failures. Before investing in performance parts, inspect and service these critical areas of the 2008 Infiniti G35:

1. Gallery Gaskets: While early VQ35DE engines had oil consumption issues, the HR motor solved most of those; however, internal oil gallery gaskets behind the timing cover can degrade and leak, leading to a loss of oil pressure. Check oil pressure at idle and operating temperature.
2. Valve Cover Gaskets: Over time, the plastic valve covers warp and spark plug well seals harden, causing oil to pool in the spark plug tubes and causing misfires. Replace the entire valve cover assembly rather than just the gaskets for a permanent fix.
3. Cooling System: The plastic bleeder port and radiator end tanks are prone to cracking. Upgrading to an aluminum radiator and fresh hoses prevents catastrophic overheating.
4. Suspension Bushings: Front lower control arm liquid-filled bushings commonly rupture, resulting in a clunking noise when braking and vague steering. Replace these with solid rubber or polyurethane units.

Frequently Asked Questions

Can I drop a VQ35HR engine into an older G35 sedan?

While physically possible, it is a complex and expensive undertaking. The VQ35HR uses a completely different wiring harness, ECU, transmission bellhousing bolt pattern, and a taller hood to clear the dual throttle body plenum. It is far more cost-effective to purchase a 2007–2008 model if you want the HR platform.

What is the best exhaust system for a VQ35HR to avoid rasp?

Systems featuring internal Helmholtz chambers or true X-pipes, such as those made by Motordyne or Fast Intentions, are widely considered the gold standard for eliminating the unwanted rasp and drone common with cheap straight-pipe setups.

Do I need a tune after installing a cold air intake?

While the car will run without a tune after installing intakes, a custom dyno tune allows the ECU to fully capitalize on the increased airflow, optimizing air-fuel ratios and unlocking hidden horsepower while smoothing out throttle response.

How do I fix the outdated navigation screen in a 2008 G35?

You can install a aftermarket double-DIN head unit using a specialized dash integration kit or utilize custom tablet integration kits that overlay modern touchscreens onto the upper dashboard display area while retaining HVAC controls.

What tire size should I run on 19-inch wheels for a lowered G35?

For a flush look without excessive rubbing on a lowered suspension, a common tire size setup is 245/40R19 in the front and 275/35R19 in the rear, paired with wheels measuring 9.5 inches wide in the front and 10.5 inches in the rear.

Final Recommendations for Your Build

Executing a successful 2008 Infiniti G35 custom build requires patience and a systematic approach. Always prioritize mechanical health and suspension integrity before chasing peak horsepower numbers. Address worn-out bushings, upgrade the cooling system, and ensure your braking capability matches your engine modifications. By treating the VQ35HR platform with respect and investing in quality components, you will create a reliable, rewarding sports sedan that stands out on both the street and the track.