“Jason’s Impeller design keeps both my CR500 and KX500 cool in the AZ Deserts. A temp gun on the radiators shows a considerable cooling over stock.”- Douglass B.
MSV Racing OptiFlo™ “phi” High-Volume KX500 Impeller
Cooler Temps. More Power. Unmatched Flow.
If you’re serious about performance, the MSV Racing OptiFlo™ “phi” HV Impeller is a must-have upgrade for your KX500 cooling system. Designed with precision, tested under race conditions, and proven to outperform every other impeller on the market — including Frank’s MX, AS3, and Mino.
3 Ways to Improve KX500 Cooling — Only One Works
Bigger radiator area? Not an option. The KX500’s tight shrouds limit size increases, and thicker radiators only delay overheating.
Cooler air? You’re at the mercy of ambient temps — no control.
✅ Increased coolant flow? Now we’re talking. That’s exactly where the MSV “phi” impeller dominates.
Engineered for Results:
- +1.2 GPM more coolant flow vs. OEM & aftermarket units
- Up to 18°F drop in head and coolant temps
- Golden Ratio vane design (φ) = optimized flow efficiency
- Precision CNC’d from 7075 T6-511 Aluminum – stronger, lighter, and built to last
- Closer impeller-to-housing tolerances for maximum hydraulic performance
- Tested on flow benches and real-world MX race conditions
Why It Matters:
More coolant flow = faster heat extraction = cooler engine temps = more reliable horsepower.
With the “phi” impeller, your engine stays cooler longer — giving you the edge whether you’re tearing up GNCC, MX, Supermoto, Hillclimb, Sand Drags, or tight single track.
Don’t let heat soak kill your power. Build a more efficient engine with the MSV Racing OptiFlo™ “phi” Impeller — and trust the only company that shows you the data to back it up.
🛠️ Includes:
- Billet 7075-T6 OptiFlo™ “phi” Impeller
- High-quality H₂O pump cover gasket set
- Easy install. Big performance gain.
⚠️ COMPARE BEFORE YOU BUY:
Frank’s MX, Mino, and AS3? Same oversized impeller with a spacer.
MSV’s “phi” Impeller? Completely engineered from scratch for the KX500’s unique cooling demands.
📈 Trusted by Racers. Proven on Track.
Join the riders who’ve dropped temps, freed horsepower, and run at the front — with MSV Racing.
Travis McQueen (verified owner) –
Professional Workmanship!!!
JEFFREY F. (verified owner) –
Great piece for you KX500
Steve Williams (verified owner) –
Great craftsmanship.
Brock Chandler (verified owner) –
amazing stats on this, cant wait to put it to the test.
Mike Weir (store manager) –
My thoughts on the impeller after testing on my Super Moto and both my Land Speed bikes is that NOTHING cools better than the MSV Racing PHI impeller… 2 miles, 5th gear pinned… high port timing… Zero overheating and I’ve been running without shrouds. The harder you push your bike the more you need it..
Doug Haas (store manager) –
Jason, finally got around to starting my KX500 with your precision machined high flow impeller. I did not measure the flow rate of the cooling system with your impeller, but from looking in the radiator with the engine running I can see it does have significantly more flow (turbulence in the radiator) over the stocker. It’s almost like a “tempest in a teapot”. Based on that perception and measuring the clearances to the impeller housing with your impeller and the stocker, it is easy to conclude your impeller will flow more coolant and cavitate less than the stocker. From a visual comparison of the two impellers yours is more “hydrodynamically” designed, the machining is excellent and the visual appearance is outstanding over the stocker. It is a shame that a part this good is going to be covered up by the impeller housing. When the weather clears up and my surgery heals I will be doing some extended radiator temperature testing. Really good work!!
Doug Haas (verified owner) –
Price was good and competitive.
freundlichertaxifahrer (store manager) –
Top-notch part, offering great tuning at a fair price.
Ursilly (store manager) –
I received the package quickly. impeller definitely makes the bike run noticeably cooler!
Douglass B. (verified owner) –
Jason’s Impeller design keeps both my CR500 and KX500 cool in the AZ Deserts. A temp gun on the radiators shows a considerable cooling over stock.
tribalbc (store manager) –
Put this on my kx500 snowbike. Very impressed!! Saw a temp difference of 40 to 50