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BHP Calculation Formula:
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The WHP to BHP conversion calculates brake horsepower (engine output) from wheel horsepower (power measured at the wheels), accounting for drivetrain power losses. This is essential for understanding true engine performance versus actual delivered power.
The calculator uses the BHP conversion formula:
Where:
Explanation: The formula accounts for power losses through the transmission, driveshaft, differential, and other drivetrain components to determine the actual engine output.
Details: Understanding the relationship between WHP and BHP is crucial for vehicle performance tuning, comparing engine modifications, and accurate power measurement for racing and automotive applications.
Tips: Enter wheel horsepower in hp and drivetrain efficiency as a decimal (0.85 for 85% efficiency). Typical efficiency values: 0.85 for RWD, 0.88 for FWD, 0.90 for AWD.
Q1: What's the difference between WHP and BHP?
A: WHP is power measured at the wheels, BHP is power measured at the engine crankshaft. WHP is always lower due to drivetrain losses.
Q2: What are typical drivetrain efficiency values?
A: Rear-wheel drive: 0.83-0.85, Front-wheel drive: 0.87-0.88, All-wheel drive: 0.85-0.90, depending on vehicle design and condition.
Q3: Why is WHP lower than BHP?
A: Power is lost through friction in the transmission, driveshaft, differential, wheel bearings, and tire deformation before reaching the wheels.
Q4: How accurate is this conversion?
A: The conversion provides a good estimate, but actual drivetrain losses can vary based on vehicle age, maintenance, and specific components.
Q5: Can I use this for dyno tuning?
A: Yes, this conversion is commonly used to estimate engine power from chassis dynamometer measurements during performance tuning.