AEM 30-3301 V3 Water/Methanol Injection Kit 5-Gallon HD Diesel 40 PSI

Vehicle Fitment

• Universal - designed primarily for turbocharged diesel trucks and SUVs (HD applications). Also compatible with turbocharged or supercharged gasoline engines. The boost-dependent HD internal MAP controller supports boost pressures from 1-40 PSI.
• For diesel applications running more than 40 PSI of boost, use the AEM HD Multi-Input kit (PN 30-3351), which accepts an external 0-5v MAP sensor and frequency-based MAF or IDC inputs for ultra-high-boost and alternative triggering strategies.
• This is the version with the 5-gallon tank included (PN 30-3301). The identical kit without the tank is available as PN 30-3303 for installations where a separate fluid reservoir is used.

Fitment Notes

• The HD boost-dependent controller's on-board MAP sensor accepts a boost hose connection via the molded-in barbed nipple on the controller housing. The boost reference must be taken from a reliable post-compressor manifold pressure source. Boost Safe activates if the reference hose is disconnected or develops a leak during operation.
• The 5-gallon tank includes an anti-starvation reservoir - a critical diesel-specific design feature that prevents fluid starvation during sustained hard acceleration, cornering, or uphill driving where fluid can slosh away from the tank's outlet. On a diesel truck making sustained high-boost pulls on a dyno or drag strip, this prevents the system from running dry mid-run due to sloshing.
• The injection nozzle should be placed downstream of the turbocharger compressor outlet, upstream of the throttle body (if equipped) or intake manifold inlet, to maximize charge air cooling effectiveness. The tank must be mounted below the injection nozzle unless the optional WMI solenoid (PN 30-3326) is used to prevent siphoning when the system is inactive.
• AEM recommends running an inline WMI fluid filter (PN 30-3003) upstream of the pump for all WMI systems. For installations with the pump/tank above the injection nozzle, the optional High-Flow Low-Current WMI Solenoid (PN 30-3326) prevents unintended fluid draining when the system is off.
• Maximum methanol concentration: 50%. AEM strongly recommends never exceeding a 50:50 water-to-methanol ratio. The flow sensor in AEM WMI systems can be damaged at higher concentrations, and the safety hazards of neat or high-concentration methanol in an under-hood environment are significant. Methanol is toxic, highly flammable, and burns with a nearly invisible flame.

Features

• Water/methanol injection delivers a measurable set of diesel-specific benefits beyond the power gains associated with gas applications. On turbo diesel engines, WMI reduces exhaust gas temperatures (EGTs) - a critical concern on high-boost, high-fueling diesel builds where EGT spikes are a primary engine longevity limiter. WMI also actively cleans carbon deposits that accumulate in the intake tract from the engine's exhaust gas recirculation (EGR) system, reducing the frequency and severity of intake cleaning required over the engine's service life.
• The HD controller includes a high-amperage pump driver with dedicated over-current, over-voltage, and under-voltage protection - hardware protection that the standard gas controller (30-3300) does not include. This makes the HD controller appropriate for the larger, higher-draw pump configurations that diesel performance applications often require.
• The HD controller provides two system status LED indicators rather than one: one shows pump duty cycle and one shows system errors, allowing the operator to see both injection activity level and system health status simultaneously at a glance.
• Pump open and short detection with indication is built into the HD controller and functions continuously - even when the pump is not actively running. This means wiring faults and pump failures are detected and displayed proactively, not only when the system is actively injecting.
• A manual test button on the HD controller directly triggers the pump for priming and system verification during setup, without requiring the engine to be running or boost to be present - a significant convenience advantage during initial installation and troubleshooting.
• The progressive boost-dependent controller scales injection flow in direct proportion to boost pressure, producing a linear fluid delivery output that better matches the engine's cooling and detonation suppression demand at each point along the power curve. Flow delivery starts at the programmed start pressure and reaches full activation at the programmed full pressure, with both set via large turn-resistant knobs on the controller face.
• The Boost Safe failsafe output monitors the entire WMI system and produces a grounded output signal if it detects any fault condition - low fluid, short, bad connection, broken wire, overheated pump, or out-of-range voltage. This output can trigger: a warning light, ignition timing retard through a standalone ECU, boost pressure reduction via a wastegate solenoid, or a fuel map switch on a programmable ECU. Combined with the conductive tank sensor, Boost Safe can put the engine into safe mode before the system runs dry.
• The V3 injector uses AEM's Swirl Generator Technology to improve fluid atomization and cooling speed compared to the previous V2 design. Three interchangeable nozzle inserts (250, 500, and 1000cc/min) are included, with nozzle swaps requiring no tools or re-plumbing. The integral check valve prevents fluid from back-draining through the nozzle when the system is inactive.
• The 200 PSI recirculation-style pump runs continuously using an internal bypass rather than switching on and off, producing stable line pressure, consistent flow rates, and significantly quieter operation than switched-style pumps. Santoprene diaphragm and EPDM seals provide long-term chemical compatibility with methanol-water mixtures.

Specifications

• Part Number: 30-3301
• Brand: AEM Electronics
• System Version: V3 (V3 injector/nozzle; current production)
• Controller Type: Boost-Dependent HD Progressive; on-board MAP sensor
• Boost Range: 1-40 PSI (internal MAP sensor maximum)
• HD Controller Extras: High-amp pump driver; over-current/over-voltage/under-voltage protection; dual status LEDs; pump open/short detection; manual test button; error protection output with over-temp protection
• Pump Type: Recirculation-style, internally bypassed, heavy-duty HD
• Pump Pressure: 200 PSI
• Pump Seals: Santoprene diaphragm / EPDM seals
• Injector: V3 precision-machined billet aluminum; Swirl Generator Technology; integral check valve
• Nozzles Included: 250cc/min, 500cc/min, 1000cc/min (3 interchangeable)
• Tank Capacity: 5 gallon
• Tank Features: Anti-starvation reservoir; integral conductive low-fluid level sensor
• Failsafe Output: Boost Safe - grounded output on fault
• Dash Light: LED system status and low fluid warning
• Max Methanol Concentration: 50% (AEM recommended maximum)
• Tank-Less Version: PN 30-3303
• Multi-Input HD Version: PN 30-3351 (external MAP / MAF / IDC)
• Emissions: Legal for emissions-controlled, uncontrolled, and racing vehicles
• Warranty: 12-month limited

Included Components

• 1x Boost-Dependent HD progressive controller (on-board MAP, 40 PSI max)
• 1x 200 PSI heavy-duty recirculation pump
• 1x 5-gallon fluid tank with anti-starvation reservoir and integral conductive low-fluid sensor
• 1x V3 billet aluminum WMI injector assembly with integral check valve and Swirl Generators
• 3x Interchangeable nozzle inserts: 250cc/min, 500cc/min, 1000cc/min
• 1x LED dash light (system status and low fluid warning)
• 1x Wiring harness (color-coded, positive-lock connector, integrated pump power and ground, optional solenoid wire)
• All installation hardware, fittings, and boost reference hose

Product Description

The AEM 30-3301 is the V3 Water/Methanol Injection Kit with the HD Boost-Dependent Controller for turbocharged diesel trucks and SUVs, and high-boost forced induction gasoline applications. It is the heavy-duty version of AEM's boost-dependent WMI kit line - a complete system with everything required for installation, including a 5-gallon tank with anti-starvation reservoir, the HD progressive controller with 40 PSI on-board MAP sensor capability, the 200 PSI recirculation pump, and the V3 injector assembly with three interchangeable nozzle sizes.

The HD controller is the core differentiator from the standard gas kit (30-3300). It adds a high-amperage pump driver, over-current/over-voltage/under-voltage electrical protection, dual status LEDs for simultaneous duty cycle and error monitoring, continuous pump open/short detection, and a manual test button for pump priming without requiring a running engine. These additions address the real-world demands of large diesel performance applications - higher pump current draw, more critical EGT and engine protection requirements, and the need for confident system verification during setup on trucks where access to a running engine for testing may be limited.

The diesel-specific benefits of WMI include reduced exhaust gas temperatures (a primary longevity concern on high-boost diesel builds), intake carbon cleaning that reduces EGR deposit accumulation, and suppression of harmful combustion knock that allows more aggressive tuning without higher-octane fuel. The 5-gallon anti-starvation tank provides substantially more operating range than the 1-gallon gas kit, and the anti-starvation reservoir prevents the fluid starvation failures that can occur during sustained hard pulls when fluid sloshes away from a simple tank outlet. Maximum methanol concentration is 50% - never run neat methanol in this or any AEM WMI system. Warranty: 12-month limited.