The ignition system of your Subaru WRX is a critical component that directly influences engine performance, fuel efficiency, and overall driving enjoyment. While the factory stock system is engineered for reliability and daily commuting, it often leaves performance on the table, especially for enthusiasts seeking sharper throttle response or higher horsepower. Upgrading to a modern electronic ignition like the Pertronix Ignitor II represents a cost-effective path toward unlocking your WRX's true potential. This guide provides a comprehensive breakdown of the costs, installation process, and real-world results of swapping your stock ignition for a Pertronix Ignitor II, helping you make an informed decision.

Whether you own a classic WRX or a more recent model with a distributor-based ignition, this upgrade can deliver measurable gains. Unlike modern coil-on-plug systems, many earlier Subaru WRX engines rely on a traditional distributor, making them ideal candidates for the Ignitor II. By replacing mechanical breaker points or even older electronic modules, the Ignitor II provides a precise, high-energy spark that can transform your engine's behavior.

Understanding the Stock Subaru WRX Ignition System

Before diving into the upgrade, it's essential to understand what you're working with. The stock ignition system on a Subaru WRX is designed to meet emissions standards and provide consistent performance under normal driving conditions. Key components include the distributor, ignition coil, spark plugs, spark plug wires, and the associated control module or points assembly.

The distributor houses either mechanical breaker points or, in later models, a basic electronic trigger module. Points-based systems are particularly prone to wear and timing drift as the rubbing block wears down, leading to a degraded spark over time. Even older electronic modules can exhibit lag or inconsistency as they age. The stock coil is typically wound to deliver a spark adequate for factory boost levels and compression, but it may struggle to provide sufficient energy for modified engines or when running increased boost.

Limitations of the Stock Setup

  • Timing Inaccuracy: Mechanical points can fluctuate, causing spark timing to vary from cylinder to cylinder.
  • Weak Spark at High RPMs: At higher engine speeds, the stock ignition may not deliver enough dwell time for complete coil saturation, resulting in a weak or intermittent spark.
  • Maintenance Frequency: Points require periodic adjustment and replacement, and the condenser can fail without warning.
  • Limited Headroom: For owners who have upgraded their turbo, fuel system, or intercooler, the stock ignition often becomes a bottleneck.

Why Upgrade to the Pertronix Ignitor II?

The Pertronix Ignitor II is a drop-in electronic ignition conversion kit that replaces the points or standard Hall-effect module inside your WRX's distributor. Unlike first-generation Ignitor units, the Ignitor II features adaptive dwell technology. This means the module automatically adjusts the coil charge time based on engine speed, delivering maximum spark energy at all RPMs without overheating the coil at idle.

This upgrade eliminates mechanical wear points entirely, providing a maintenance-free, consistent spark. The result is more complete combustion, which translates into smoother idle, better throttle response, and improved fuel economy. For WRX owners who have already invested in exhaust, intake, or turbo upgrades, the Ignitor II helps ensure that the additional air and fuel are fully burned in the cylinder, maximizing power output.

Key Benefits of the Ignitor II

  • Enhanced Spark Energy: Up to four times the spark voltage compared to points, ensuring reliable ignition under high compression or boost.
  • Adaptive Dwell Control: The module self-adjusts to maintain ideal coil charging, preventing pre-ignition and component stress.
  • Drop-In Installation: No permanent modifications to your distributor; the kit fits inside the stock housing.
  • Eliminates Points: No more adjusting gap or replacing points and condensers—true set-and-forget reliability.

Cost Breakdown of the Pertronix Ignitor II Upgrade

One of the main reasons the Ignitor II is so popular among Subaru WRX enthusiasts is its affordability relative to the performance gains. The total cost depends on whether you perform the installation yourself and whether you opt for additional upgrades like a high-output coil or premium spark plug wires.

Expected Expenses

  • Pertronix Ignitor II Kit (Part #91181 or equivalent for your WRX model): $110 – $180
  • Pertronix Flame-Thrower Coil (recommended for maximum performance): $50 – $90
  • Spark Plug Wires (quality aftermarket set): $40 – $80
  • Spark Plugs (NGK Iridium or Copper): $20 – $40
  • DIY Installation Tools (if needed, basic hand tools): $0 – $30
  • Professional Installation (hourly labor, typically 1-2 hours): $100 – $250

Total cost for a comprehensive upgrade ranges from approximately $220 (DIY with basic Ignitor kit and existing coil) to $450 (including upgraded coil, wires, plugs, and professional installation). For the gains achieved, this represents exceptional value versus standalone engine management or full ignition system overhauls.

For reference, the official Pertronix product page provides model-specific kit numbers and current pricing. It is always wise to verify compatibility with your specific WRX year and engine code.

Installation Process: Step-by-Step Guide

Installing the Pertronix Ignitor II is a straightforward DIY project that can be completed in an afternoon. The process assumes you have basic mechanical skills and standard hand tools such as sockets, screwdrivers, and a multimeter for testing. Always disconnect the battery negative terminal before beginning any electrical work on the ignition system.

Tools and Parts Required

  • Socket set (8mm, 10mm, 12mm)
  • Flathead and Phillips screwdrivers
  • Needle-nose pliers
  • Dielectric grease
  • Feeler gauge (if setting ignition timing after installation)
  • Timing light (recommended for final verification)

Installation Steps

  1. Prepare the Distributor: Remove the distributor cap and rotor. Mark the current position of the distributor housing to the engine block with a scratch or paint marker—this will help you approximate timing upon reassembly.
  2. Remove Points and Condenser: If your WRX still uses breaker points, unbolt and remove the points set and condenser. Disconnect the primary wire that leads from the coil negative terminal to the distributor. Set aside all stock components—they can serve as emergency spares.
  3. Install the Ignitor II Module: The Ignitor II fits onto the same mounting plate that held the points. Secure it with the provided screws. Ensure the module's sensor aligns with the distributor shaft's rotating magnet or reluctor. Apply a small dab of dielectric grease to the module's base for heat transfer.
  4. Route Wiring: Connect the red wire from the Ignitor to the ignition coil positive terminal (or to the ignition switch wire supplying +12V with the key ON). Connect the black wire to the coil negative terminal. Secure any loose wiring with zip ties to avoid contact with the spinning rotor.
  5. Install High-Output Coil (Optional but Recommended): If you purchased the Pertronix Flame-Thrower coil, mount it using the original coil bracket. Connect the positive wire from the Ignitor and the main ignition power to the coil positive. Connect the Ignitor black wire and the tachometer wire (if applicable) to the coil negative.
  6. Reassemble the Distributor: Install the rotor, then fit the distributor cap. Ensure the cap engages properly and all spark plug wires are seated firmly. Use new spark plugs and wires if you are refreshing those components.
  7. Reconnect Battery and Test: Double-check all connections, then reconnect the battery. Turn the key to the ON position (do not start the engine). The Ignitor II LED indicator (if equipped) should light up. If not, check for voltage at the coil. Crank the engine—it should start immediately. Use a timing light to verify that your base timing is set correctly (typically 10-15 degrees BTDC for a WRX, depending on modifications).

Common Installation Pitfalls

  • Incorrect Wire Routing: Make sure the Ignitor wires do not touch hot engine components or moving parts inside the distributor.
  • Coil Polarity: Always connect the red wire to coil positive (+) and black to coil negative (-). Reversed polarity will weaken the spark.
  • Timing Shift: In some cases, the Ignitor II may alter the trigger point slightly. Always check and adjust base timing after installation.

Expected Performance Results

After installing the Pertronix Ignitor II, most Subaru WRX owners report noticeable and immediate improvements. The most frequently cited gains include:

  • Faster Start-Up: The engine fires almost instantly, even after sitting for days. Cold starts are notably smoother with less cranking.
  • Smother Idle: The adaptive dwell technology eliminates the erratic idle common with worn points or aging modules. The engine no longer hunts or stumbles at stoplights.
  • Improved Throttle Response: Part-throttle acceleration feels crisper. There is a reduction in the lag between pressing the accelerator and the engine responding.
  • Fuel Economy Gains: Because combustion is more complete, many drivers see a 2-5% improvement in fuel mileage. Over time, this can offset the upfront cost of the kit.
  • Increased Mid-Range Torque: Consistent spark delivery helps the engine build power more linearly. Owners often report a "seat of the pants" increase in pulling power from 2500-4500 RPM.

While peak horsepower gains are typically modest (around 5-10 hp on a stock engine), they become more significant when paired with other modifications. For example, a Subaru WRX forum discussion documented a case where an owner with a Stage 2 setup (downpipe, tune, intake) gained 12 wheel horsepower and 15 ft-lbs of torque simply by switching from points to the Ignitor II and a Flame-Thrower coil. The consistent spark eliminated misfires under full boost that had been limiting the tune.

Compatibility and Considerations for Your WRX

Before purchasing, verify that your specific Subaru WRX model uses a distributor-based ignition. Older WRX models (particularly those from the late 1990s to early 2000s in various markets) often have distributors. Later models with coil-on-plug systems are not compatible with the Ignitor II. Check the distributor cap and rotor configuration—if your WRX has an optical or Hall-effect sensor already, the Ignitor II may not be necessary, but it can still improve dwell consistency.

Is Your WRX Compatible?

  • 1994-2000 Subaru Impreza WRX (EJ20G, EJ20K): Yes, these models use a distributor.
  • 2001-2005 Subaru Impreza WRX (EJ205, EJ207): Many of these still have distributors, but check your specific engine bay.
  • 2006+ WRX: Most models have switched to coil-on-plug or DIS, but verify before purchasing.

If your WRX has been swapped with an older engine or uses a standalone engine management system, consult the manufacturer for wiring specifics. The Ignitor II works best with a standard inductive ignition coil; do not use it with capacitive discharge (CD) ignitions.

Maintenance and Longevity

One of the primary advantages of the Pertronix Ignitor II is the reduction in ignition maintenance. Once installed, there are no points to adjust, no condenser to fail, and no rubbing block wear to worry about. The module itself is solid-state and sealed against moisture and dust. Many users report tens of thousands of miles of trouble-free operation.

However, you should still perform routine checks:

  • Inspect the distributor cap and rotor annually. The Ignitor II does not eliminate cap and rotor wear—they still transmit high-voltage spark and will erode over time.
  • Verify spark plug gap. With a higher-energy spark, you can often open the gap slightly (e.g., from 0.028" to 0.032") for better flame kernel propagation, but stay within the manufacturer's safe range.
  • Keep the coil and Ignitor wiring clean and free of oil or coolant leaks. Heat is the enemy of electronic modules.

Complementary Upgrades to Maximize Results

To truly get the most out of your upgraded ignition, consider these supplementary modifications:

  • High-Performance Coil: The Pertronix Flame-Thrower coil is designed to work synergistically with the Ignitor II. It has a lower primary resistance that allows the adaptive dwell cycle to saturate more completely.
  • Low-Resistance Spark Plug Wires: Replacing aged OEM wires with premium silicone jacketed wires reduces voltage loss between the coil and plugs.
  • Cold Range Spark Plugs: For heavily modified engines (high boost, nitrous), a colder heat range plug can prevent pre-ignition and detonation.
  • Fuel System Upgrade: A consistent spark demands consistent fuel delivery. Ensure your fuel pump, injectors, and regulator are up to the task.

For a deeper dive into ignition tuning and advanced modifications, resources such as Engine Builder Magazine offer technical articles on spark energy and combustion efficiency.

Conclusion

Upgrading your Subaru WRX ignition system to the Pertronix Ignitor II is one of the most cost-effective performance modifications you can make. For an investment of roughly $200 to $450, you gain a maintenance-free, high-energy spark that improves drivability, reliability, and fuel economy. The installation is straightforward for a DIY enthusiast, and the results are immediately apparent. While the Ignitor II alone won't transform your WRX into a track monster, it removes a fundamental limitation in the stock ignition system, allowing your engine to run more efficiently and respond more sharply.

Whether you drive a stock daily driver or a modified project car, the Ignitor II delivers consistent, reliable performance that stands up to the demands of turbocharged Subaru engines. Pair it with complementary upgrades like a high-output coil and fresh spark plugs, and you will unlock smoother power delivery and a more enjoyable driving experience. Consult the official Pertronix website for model-specific guidance, and join online Subaru communities for real-world feedback from owners who have already made the switch.