A good electric fan can make or break your cooling setup, especially when you’re short on space.
The Flex-A-Lite 105390 Flex-Wave LoBoy is built for those conditions—delivering impressive airflow in a low-profile design that fits where most fans can’t.
With its 16-inch puller configuration, 2,500 CFM capacity, and quiet Flex-Wave blade technology, this fan provides a smart balance of power, efficiency, and durability for modern and classic builds alike.
Key Features of the Flex-A-Lite 105390 Flex-Wave LoBoy
This model takes on the biggest challenge in performance cooling—achieving high airflow in limited space—without compromising efficiency or noise control.
Low-Profile Build
At just 2-5/16 inches deep, the LoBoy is ideal for tight clearances. It often fits without requiring radiator relocation or trimming, making it perfect for custom swaps and compact engine compartments.
Flex-Wave Blade Design
The fan’s signature S-shaped blades are engineered for performance. The wave curvature smooths airflow, reduces drag, and minimizes the harsh “whoosh” noise common in flat-blade fans. This design not only keeps temperatures in check but also makes operation quieter and more stable.
High-Output Cooling
The LoBoy moves up to 2,500 cubic feet of air per minute—matching the performance of larger units while maintaining a slim fit. It’s a practical upgrade for vehicles with modified or high-compression engines that generate excess heat.
Built for Durability
Reinforced nylon blades and a sealed electric motor withstand high under-hood temperatures and vibration. The material resists warping, ensuring the fan maintains performance even during extended operation.
Easy Installation
All necessary mounting hardware comes included. The kit supports direct radiator installation, saving time and reducing the need for extra brackets or fabrication.
Performance and Technical Specs
Before installing an electric fan, it helps to understand what kind of load and airflow it brings to your system. The LoBoy offers an ideal balance of electrical efficiency and cooling power.
- Diameter: 16 inches — provides broad coverage without excess bulk.
- Airflow: 2,500 CFM — strong enough for most performance and street applications.
- Power Draw: 18–19 amps — easily supported by most alternators.
- Configuration: Puller-style only — designed for behind-radiator installation.
- Controller Compatibility: Works with aftermarket fan controllers for temperature-based activation.
These specifications make it a good fit for both daily drivers and high-performance vehicles that need consistent temperature control.
Installation and Setup
Installing the LoBoy is straightforward but benefits from a few precautions and proper planning.
- Direct Mounting: Use the included brackets to secure the fan directly to the radiator.
- Custom Fitment: The fan’s flexible mounting system adapts well to nonstandard radiator shapes or custom builds.
- Wiring: Use 10- to 12-gauge wire with a relay system to manage the 18-amp draw safely.
- Clearance Check: Measure space behind the radiator carefully, accounting for belts or pulleys.
DIY installers with basic electrical knowledge can handle the job, though professional wiring ensures the safest and most reliable performance.
Best Vehicle Applications
The Flex-A-Lite 105390 works across several vehicle categories, adapting to different setups without losing performance.
- Performance Cars: Handles increased heat from turbocharged or modified engines.
- Tight-Space Builds: Ideal for vintage chassis or small-engine compartments where clearance is minimal.
- Racing: Withstands high vibration and sustained high-load conditions.
- Daily Drivers: Offers efficient cooling at idle without parasitic power loss.
- Restorations: Delivers modern reliability while staying visually discreet.
Each of these applications benefits from the fan’s balance of power, compactness, and quiet operation.
Cooling Efficiency in Real Conditions
In real-world use, the LoBoy can reduce engine temperatures by 15–25°F under demanding conditions. The most noticeable difference appears at idle or in stop-and-go traffic—where mechanical fans lose efficiency.
The Flex-Wave design also cuts noise levels by roughly 3–5 decibels compared to flat-bladed fans, offering a smoother sound profile. Most users report consistent operation for seven to ten years before service or replacement is needed.
Optimizing System Performance
To get the best results, pair the LoBoy with a fan controller and proper shrouding.
- Fan Controller: Set to engage between 180°F and 195°F for balanced operation.
- Shroud Coverage: Aim to cover 70–80% of the radiator core to prevent airflow loss.
- Electrical Support: A 60-amp alternator or higher is recommended for older vehicles with additional electrical accessories.
These small adjustments can greatly improve cooling consistency and component lifespan.
Final Take
The Flex-A-Lite 105390 Flex-Wave LoBoy Puller Electric Fan offers exceptional cooling in tight spaces.
Its 2,500 CFM output, slim design, and quiet Flex-Wave blades make it one of the most efficient compact fans available today.
Built tough with reinforced nylon and designed for easy installation, it’s a reliable choice for anyone upgrading a performance engine, restoring a classic, or solving clearance problems in a custom build.
For powerful cooling without compromise, the LoBoy remains a top-tier solution.
Leave a Reply