The Infiniti G37 strikes a rare balance between luxury and performance, offering a potent VQ37VHR engine and rear-wheel-drive dynamics that make it a favorite among enthusiasts. With a budget of under $2,000, you can transform this grand tourer into a sharper, quicker machine. This guide breaks down high-impact modifications that deliver measurable gains in horsepower, handling, and driver engagement without requiring a second mortgage.

1. Cold Air Intake Systems

A cold air intake (CAI) is one of the simplest bolt-on upgrades for the G37. By drawing cooler, denser air from outside the engine bay, it improves combustion efficiency and yields modest but noticeable power gains. Most systems also replace the restrictive factory airbox with a larger filter and smoother intake tubes.

Key Benefits

  • +8 to +12 whp on a stock tune with proper heat shielding
  • Sharper throttle response, especially in mid-range rpms
  • Deepened intake growl that enhances the VQ’s character

The Stillen Gen 2 and Injen SP Series are proven designs that include carb-legal EO numbers in many states. The Z1 Motorsports 3-inch intakes are another strong choice for those planning future tuning. Installation takes 2–3 hours and requires only basic hand tools. Pairing a CAI with a high-flow air filter (like a dry synthetic unit) reduces maintenance and avoids oil contamination of MAF sensors.

For maximum gains, consider a system that relocates the filter behind the bumper or uses a sealed heat shield. Without such shielding, engine bay heat soak can negate gains in stop-and-go traffic.

2. Performance Exhaust Systems

A freer-flowing exhaust reduces backpressure, allowing the VQ37VHR to exhale more efficiently. The result is a power bump of 5–15 whp depending on the rest of your setup, plus a soundtrack that ranges from refined to aggressive.

Cat-Back vs Axle-Back

Cat-back exhausts replace everything from the catalytic converters rearward. They offer the largest gains but cost $800–$1,200. Axle-back systems replace only the rear mufflers, delivering a deeper note with minimal power gains (0–5 whp) and lower cost ($300–$600). For under $2,000 total, a cat-back is the smarter investment if paired with other mods.

Top Picks

  • Fast Intentions (FI) resonated cat-back – known for zero drone and excellent build quality
  • Motordyne Shockwave – offers the best power gains and a refined, exotic tone
  • ARK GRiP – valved option that lets you switch between loud and quiet modes

303 stainless steel construction resists corrosion better than T-304, but T-409 is lighter and cheaper. Mandrel-bent tubing (2.5-inch or 3-inch) maintains consistent diameter. A true dual 2.5-inch system is ideal for naturally aspirated builds, while 3-inch suits forced induction later.

3. ECU Tuning

ECU tuning is the single most effective modification for the G37. The factory calibration is conservative; a custom tune can unlock 15–25 whp on an otherwise stock car, and even more with bolt-ons. Tuning also improves throttle mapping, raise the speed limiter, and optimize transmission shift points in automatic cars.

Options Within Budget

  • UpRev Osiris – the most common platform; $300–$400 for the tune file, plus a $200 cable. DIY street tuning is possible with a wideband O2 sensor
  • Ecutek – offers more advanced features like flex-fuel support; $600–$800 including pro dyno time
  • Remote tuning services – companies like Admin Tuning or RS Enthalpy provide base maps and data logging support for ~$500

A dyno tune at a reputable shop typically runs $400–$600 and yields the most reliable results. For automatic G37s, be sure the tuner adjusts line pressure to crisp up shifts. Avoid generic “canned” tunes that ignore your car’s specific modifications and fuel quality.

Pair a tune with 93-octane fuel (or E85 with flex fuel sensor) to maximize gains. Budget the cost of tuning early in your build, as it amplifies the benefit of every other bolt-on.

4. Upgraded Suspension Components

The G37’s stock suspension leans toward comfort, with noticeable body roll and soft damping. Targeted upgrades can transform cornering grip and steering feel while staying under $1,000.

Best Value: Sway Bars

Rear sway bar upgrade is the cheapest handling improvement. The stock rear bar is thin; a 20mm–22mm adjustable aftermarket bar (e.g., Hotchkis, Whiteline, Z1) reduces understeer and tightens turn-in for about $200–$300. Pairing it with a larger front bar (27mm–32mm) gives even more balance, but keep the rear bar two steps stiffer than the front for neutral handling.

Coilovers vs Sport Springs

If you have room in the budget, a set of entry-level coilovers like BC Racing BR or Fortune Auto 500 ($900–$1,200) allow adjustable ride height, damping, and camber. They dramatically reduce body roll and improve grip on rough roads. For $300–$400, Swift Spec-R lowering springs drop the car 1.0–1.3 inches and pair well with upgraded shocks (Koni Yellows or Bilstein B8s).

Do not overlook rear subframe bushings. The G37’s rubber differential bushings allow excessive axle hop; solid aluminum or polyurethane bushings ($100–$150) tighten rear-end response and reduce wheel hop during hard launches.

5. Lightweight Wheels

Unsprung weight matters tremendously. Reducing wheel mass by 5–8 pounds per corner improves suspension compliance, acceleration, and braking feel. For under $2,000 you can find quality cast or flow-formed wheels that shed 4–8 lbs over the heavy factory 19-inch units.

Target Specifications

  • Size: 18x9.5 or 19x9.5 with a +22 to +35 offset fits well on the G37 without rubbing
  • Weight: Aim for under 22 lbs per wheel. Factory 19s weigh 28–30 lbs
  • Construction: Flow-formed (rotary forged) offers the best strength-to-weight ratio in this price range

Enkei RPF1 (17x9, 15.8 lbs) is the track favorite but looks small on a G37. For street use, Konig Hypergram (18x9.5, 18.6 lbs) or Titanen TS5 (19x9.5, 21 lbs) provide a balance of weight, cost, and style. Used OEM Nissan GT-R wheels (20-inch, 22 lbs) also bolt on with hub-centric rings and are widely available for under $1,000.

Pair lightweight wheels with proper lug nuts and hub-centric rings to avoid vibrations. Consider wheel stud upgrades from ARP for added safety at the track.

6. High-Performance Tires

Even with all the power in the world, inadequate tires leave everything on the table. The G37’s 330+ hp demands rubber that can handle acceleration, cornering, and braking. A set of high-performance summer tires costs $600–$900 and is arguably the highest-impact safety and performance upgrade you can make.

Best Tires for the G37 Under $1,000

  • Continental ExtremeContact Sport 02 – excellent wet/dry balance, 340 treadwear, long life
  • Michelin Pilot Sport 4S – gold standard but often over budget; check for clearance
  • Firestone Firehawk Indy 500 – outstanding dry grip for the price, 340 treadwear
  • Bridgestone Potenza RE-71RS – extreme performance summer, autocross favorite but wears quickly

For daily drivers, avoid track-compound tires that heat cycle out in 10,000 miles. A 200–340 treadwear rating offers the best balance of grip and longevity. Use 245/40R19 front and 275/35R19 rear on 9.5-inch wide wheels for optimal contact patch.

Budget for a proper alignment after installing new tires. The G37 responds well to -1.5° front camber and -2.0° rear camber for improved cornering while maintaining tire life.

7. Brake System Upgrades

Stopping power becomes critical as you add more power and grip. The G37’s Akebono calipers (found on Sport models) are capable, but pad and fluid upgrades are essential. Non-Sport models with sliding calipers benefit most from a full bracket swap to larger rotors.

Under $500 Upgrades

  • High-performance brake pads: Hawk HPS 5.0 ($120) or EBC Redstuff ($140) reduce fade and dust. For track use, Carbotech XP8 or G-Loc R8 pads are ideal
  • Slotted rotors: StopTech SportStop or Centric Premium slotted ($200 for front pair) improve bite and resist glazing
  • Stainless steel brake lines: Goodridge or Z1 braided lines ($150) eliminate spongy pedal feel and handle higher heat

If your G37 has the base brakes, consider a used Akebono conversion kit (calipers, brackets, rotors) from a G37S or G37xS. These can be found for $400–$600 and provide massively improved pedal feel and heat capacity. Add Motul RBF 600 fluid ($25) to complete the system.

8. Differentials & Driveline

One often-overlooked upgrade is the VLSD (viscous limited-slip differential). The G37’s factory unit wears with mileage and allows inside wheel spin in corners. A genuine Nismo GT Pro 1.5-way LSD or Quaife ATB (automatic torque biasing) unit can transform traction but runs $1,000+ and pushes the budget. For under $200, a differential bushing insert kit from Z1 or SPL Parts eliminates slop and reduces wheel hop. Combine with a solid rear subframe bushing (added earlier) for a dramatic improvement in power delivery feel.

Putting It All Together: Sample Builds Under $2,000

Not all mods need to be done at once. Below are two balanced packages that maximize play for the money.

Street Performance Build (~$1,900)

  • Stillen Gen 2 cold air intake — $450
  • UpRev tune (mail-in base map + logging) — $500
  • Hotchkis rear sway bar — $230
  • Konig Hypergram 18x9.5 wheels — $300 (used)
  • Continental ExtremeContact Sport 02 tires (245/275) — $700
  • Z1 diff bushing insert — $45

Handling-Focused Build (~$1,850)

  • BC Racing BR coilovers — $950
  • SPL front lower control arm camber arms — $250
  • Whiteline rear sway bar — $200
  • StopTech slotted rotors + Hawk HPS pads — $400
  • Motul RBF 600 fluid — $25

Conclusion

The Infiniti G37 is a rewarding platform that responds beautifully to carefully chosen modifications. Sticking to a $2,000 budget requires prioritizing: start with a tune and cold air intake for the biggest power per dollar, then address handling with a rear sway bar and lightweight wheels. Tires and brakes complete the package, turning your G37 into a capable street performer that keeps its luxury composure. Shop for used parts on enthusiast forums to stretch your budget further, and always invest in professional alignment and maintenance before adding boost or aggressive cams. With the right approach, your G37 can punch well above its weight class—without emptying your wallet.