WHP to HP Converter (Dyno Calculator)
Determine your engine's true Crank Horsepower (BHP) from your Dyno results. Accurately account for parasitic drivetrain losses in FWD, RWD, and AWD platforms.
Dyno Power Calculator
Typical loss for selected drivetrain configuration
Enter power value above and click "Calculate" to see results
Power Comparison
No conversion yetImportant Disclaimer
Drivetrain losses vary by vehicle condition, temperature, specific components, and dyno type. These calculations provide typical estimates based on industry standards. Actual power measurements should be performed on a professional dyno for accuracy.
The Truth About Dyno Numbers
It's a common heartbreak: You buy a car advertised with 400 HP, put it on a dyno, and it only reads 330 WHP. Did the manufacturer lie? probably not.
The manufacturer sells you the Engine. They measure power at the crankshaft (BHP) in a climate-controlled room with no accessories attached. You drive the Car. Your power has to push through a transmission, driveshaft, differential, axles, and heavy wheels before it hits the ground. This journey consumes energy, known as "Parasitic Loss."
Where Does the Power Go?
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Heat Friction
The biggest thief. Gears meshing and oil churning inside your transmission generate massive heat. That heat is wasted horsepower.
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Rotational Mass
Spinning heavy steel driveshafts and axles takes energy. The heavier the components, the more sluggish the power delivery.
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Hydraulic Pressure
Automatic transmissions behave like fluid pumps. Pumping transmission fluid at high pressure consumes engine torque.
Dyno Types Matter
Not all "Dynos" read the same.
Mustang Dyno (The Heartbreaker)
"Load Bearing". It applies resistance to simulate wind drag and vehicle weight. Reads ~10-15% lower than others.
Dynojet (The Industry Standard)
"Inertia Based". It mostly measures how fast you can spin heavy rollers. Reads higher and is great for internet bragging rights.
Hub Dyno (Dynapack)
Bolts directly to the wheel hubs. Removes tire friction/slippage variables. Reads the highest.
Estimated Parasitic Loss by Drivetrain
| Platform | Manual Trans | Automatic Trans | DCT (Dual Clutch) |
|---|---|---|---|
| FWD (Front Wheel Drive) | 10% - 12% | 15% - 18% | 12% - 15% |
| RWD (Rear Wheel Drive) | 15% | 18% - 22% | 15% - 18% |
| AWD (All Wheel Drive) | 20% - 22% | 25% - 30%* | 20% - 25% |
*Older AWD automatics (like 90s Subarus) can lose up to 35%.
Common Questions
Is a Hub Dyno more accurate?
A Hub Dyno (like Dynapack) eliminates the tire variable. Tires can slip or flex on a roller dyno, skewing numbers. Hub dynos are more consistent for tuning but tend to read higher than roller dynos.
Why does my car make less HP than advertised?
Manufacturers advertise "Brake Horsepower" (Crank HP/BHP). You measure WHP. If you see a 15-20% drop, that is normal. If you see a 30% drop, check your compression or boost leaks.
Can I reduce drivetrain loss?
Marginally. You can install a lightweight flywheel, carbon fiber driveshaft, or lighter wheels. This reduces rotational mass, allowing the engine to accelerate the drivetrain faster (freeing up power).