MSV Racing OptiFlo™ CR500 "Phi" High-Volume Water Pump Impeller

Up to 20°F Cooler Operating Temperatures. Up to 2.12 HP Recovered.

The MSV Racing OptiFlo™ "Phi" High-Volume Impeller is one of the most effective cooling upgrades available for the Honda CR500.

Engineered specifically for the CR500 water pump housing, the OptiFlo™ Impeller increases coolant flow by an average of 1.5 gallons per minute throughout the RPM range. The result is improved heat transfer, lower engine temperatures, and more consistent horsepower under demanding riding conditions.

Proven Benefits

✔ Up to 20°F Lower Engine Temperatures

✔ Average 1.5 GPM Increase in Coolant Flow

✔ Up to 2.12 Horsepower Recovered

✔ Reduced Heat Soak

✔ More Consistent Power Delivery

✔ Precision CNC Machined

✔ Includes Water Pump Cover Gasket Set

Why Cooling Matters

Horsepower creates heat.

As engine temperatures rise, performance begins to fall. Heat soak reduces power, increases detonation risk, and robs your CR500 of the performance you've worked hard to build.

The OptiFlo™ Impeller helps keep coolant moving through the engine and radiators more efficiently, reducing cycle time and improving heat removal.

The result is a cooler-running engine that maintains power longer under heavy loads and high-RPM operation.

The Science Behind the OptiFlo™

Unlike conventional impellers, the OptiFlo™ "Phi" Impeller uses computer-designed vane geometry based on Golden Ratio proportions optimized specifically for the CR500 water pump housing.

Combined with extremely tight clearances between the impeller and housing, this design improves pumping efficiency and coolant flow throughout the RPM range.

Performance Comparison

Standard Impeller = Lower Coolant Flow

MSV OptiFlo™ Impeller = +1.5 GPM Average Flow Increase

Cooling Performance

Competitive Impellers = Higher Operating Temperatures

MSV OptiFlo™ Impeller = Up to 20°F Cooler

Dyno Tested

Testing showed up to:

2.12 Horsepower Recovered Across a 1,750 RPM Range

More cooling efficiency means more usable horsepower.

Built for Every Type of CR500 Rider

Whether you're racing or riding:

• Outlaw Kart
• Motocross
• GNCC
• Hill Climb
• Sand Drags
• Supermoto
• Woods Riding
• Dunes
• Trail Riding

The OptiFlo™ Impeller helps your CR500 stay cooler and perform more consistently.

Why Riders Choose MSV Racing

Many aftermarket CR500 impellers use similar oversized designs.

The OptiFlo™ Impeller was developed using real engineering, flow testing, temperature testing, and dyno validation.

We don't just make claims—we publish the data.

That's the MSV Racing difference.

What's Included

• MSV Racing OptiFlo™ "Phi" High-Volume Impeller
• Water Pump Cover Gasket Set (2 Gaskets)

Everything needed for a straightforward installation.

Customer Review

★★★★★

"Fantastic fit and finish. Easy install. This guy does great work to improve the sore spots on our beloved big bores."

— Billy Brown

If you're serious about keeping your CR500 cooler, stronger, and more consistent under load, the MSV Racing OptiFlo™ "Phi" Impeller is a must-have upgrade.

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