The Nissan 370Z has earned its reputation as a driver's sports car, blending sharp handling with a high-revving VQ37VHR V6 engine. While the stock power output is respectable, enthusiasts know that small, focused upgrades can unlock noticeable gains without requiring a rebuild. Ignition system enhancements are among the most cost-effective modifications, targeting combustion efficiency to improve throttle response and horsepower. This guide covers the best ignition upgrades for the 370Z that can deliver over 10 horsepower when combined, with a target budget of under $200 for the core components.

Understanding Ignition Upgrades

The ignition system's primary role is to ignite the air-fuel mixture at the precise moment. Stock components are calibrated for reliability, emissions compliance, and smooth operation across all conditions. Aftermarket ignition parts improve the energy, consistency, and timing of the spark. A stronger spark burns fuel more completely, reducing unburned hydrocarbons and extracting more power from each combustion event. This translates to gains in horsepower, improved throttle response, and sometimes better fuel economy under normal driving. Key areas for upgrade include spark plugs, ignition coils, and supporting calibration via an ECU tune or intake improvements.

The VQ37VHR engine in the 370Z uses a coil-on-plug design, meaning each cylinder has its own ignition coil mounted directly over the spark plug. This eliminates the need for traditional spark plug wires, which were common on older Nissan platforms. Upgrades focus on the spark plug electrode material and coil output energy. Even if your budget is tight, replacing worn spark plugs with high-performance ones is a quick win.

Top Ignition Upgrades Under $200

The following upgrades can be completed for under $200 in parts, especially if you perform the installation yourself. Combined, they can yield a noticeable 10-15 horsepower gain while improving overall drivability.

High-Performance Spark Plugs

Spark plugs are the first line of defense against weak combustion. The factory plugs are adequate, but upgrading to a precious-metal design offers several advantages. Iridium and platinum plugs provide a sharper spark, longer service life, and better heat dissipation. For the 370Z, the VQ37VHR engine requires plugs with a specific heat range and gap. A high-performance plug preserves the spark under higher cylinder pressures, which is beneficial if you plan to add more aggressive modifications later.

Recommended options:

  • NGK Iridium IX (LFR6AIX-11): These are a direct replacement with fine-wire iridium tips. They offer improved ignitability and last up to 60,000 miles. Gap them to 0.044 inches.
  • Denso Iridium Power (IK20TT): Twin-tip design for a stable spark. Known for sharper throttle response. Gap to factory spec.

Expect to pay around $40-$60 for a set of six. Install yourself with a spark plug socket and torque wrench. For more details, check the Z1 Motorsports plug selection.

Upgraded Ignition Coils

The ignition coils on the 370Z generate the high voltage needed to fire the plugs. Stock coils are reliable but can degrade over time, especially if the engine has high mileage. Upgraded coils are often designed with better insulation, improved windings, or higher output to deliver a more energetic spark. This is particularly beneficial at high RPMs where coil saturation time decreases. A stronger coil ensures no misfires and complete combustion under load.

Top picks:

  • OEM Nissan coils (22448-JK00A): A quality replacement if yours are worn. The factory coil is sufficient for mild upgrades.
  • MSD Blaster Coils (82525): Aftermarket coils with higher voltage potential. They work well with aftermarket tunes and high-performance plugs.
  • Genuine Denso Coils (673-1303): Original equipment supplier, same as OEM. Reliable and affordable at around $80-$120 for a set.

Coil prices range from $15 to $30 each, so a full set of six can stay under $180. Installation involves removing the engine cover and intake duct, then unbolting each coil and swapping. A set of new coils combined with iridium plugs is a solid foundation. Concept Z Performance carries both OEM and aftermarket coils.

Cold Air Intake (Supplemental)

While not strictly an ignition upgrade, a cold air intake directly supports the ignition system by providing denser, cooler air to the engine. This improves combustion efficiency and amplifies the gains from upgraded spark plugs and coils. The 370Z's stock airbox is restrictive, so a well-designed intake can reduce intake air temperatures and improve throttle response. On its own, a cold air intake may add 5-10 horsepower, but combined with ignition upgrades, the total gain is greater.

Recommended intakes:

  • Injen SP Series (SP2730P): Long-tube design with hydroshield. Retains factory MAF sensor location for easy tuning.
  • K&N 69 Series Typhoon (69-1250TP): Aluminum tube with a washable filter. Noticeable intake sound and mid-range gains.

Cold air intakes typically cost $200-$300, which exceeds the $200 target if included. However, you can start with plugs and coils for under $200, then add the intake later to push total horsepower gains to 15-20.

ECU Tune: Extracting the Maximum

An ECU recalibration is the final piece that ties all ignition upgrades together. The factory engine control unit (ECU) runs conservative timing and fuel maps. A tune adjusts ignition timing curves, air-fuel ratios, and other parameters to take advantage of better spark and airflow. For the 370Z, a well-known option is an off-the-shelf tune from Admin Tuning or a remote tune via an UpRev or ECUTEK device. A tune alone can unlock 10-15 horsepower on a stock engine, and with intake and ignition upgrades, the gains climb to 20-30 horsepower.

Cost for a basic tune starts around $300 for a flash, plus the cost of a cable. This exceeds the $200 budget, but it's the most influential upgrade for overall performance. If you're strictly limited to $200, focus on spark plugs and coils first, then save for a tune later. The tune will maximize the return on your ignition investment.

Installation Tips for DIY Tuners

Installing ignition upgrades on the 370Z is straightforward with basic hand tools. Here are some practical tips:

  • Disconnect the battery: Always disconnect the negative terminal before working on the ignition system to avoid electrical shock or damage to the ECUs.
  • Clean around the spark plug recess: Use compressed air or a vacuum to remove debris before pulling the plug. Dirt can fall into the cylinder if the plug well is dirty.
  • Use a torque wrench: Spark plugs should be tightened to spec (18-20 ft-lbs for the 370Z). Overtightening can strip the threads in the aluminum head.
  • Check the gap: Even new plugs may need gapping. Use a feeler gauge and adjust carefully. Too wide a gap can cause misfire at high RPM.
  • Coil installation: Apply a small amount of dielectric grease to the coil boot to prevent silicone tracking and corrosion. Ensure the connector clicks securely.
  • Test drive: After installation, start the engine and let it idle. Check for any check engine lights. A brief test drive will confirm improved throttle response.

For a more detailed walkthrough, the The370Z.com forum has DIY guides with photos.

Conclusion

Upgrading the ignition system on your Nissan 370Z is a proven path to unlocking extra horsepower without draining your wallet. By starting with high-performance spark plugs and upgraded ignition coils, you can achieve over 10 horsepower for under $200, especially if you install them yourself. Adding a cold air intake and an ECU tune later compounds the gains, transforming the driving experience. These modifications not only increase peak power but improve throttle response and engine smoothness. Whether you're preparing for track days or want a sportier daily driver, these ignition upgrades deliver real, measurable benefits.

Focus on quality components from trusted brands like NGK, Denso, and MSD, and remember that proper installation and tuning make the difference. Your 370Z will reward you with sharper acceleration and a more responsive engine that's ready to rev.