by 
The Curious Bag
-
Horsepower is a value that is calculated by indexing torque output and engine RPM, and is probably the single most defining factor when discussing a vehicle's performance. Methods of calculating horsepower vary by approach and accuracy.
Stock Horsepower
This is the easiest to find, as engine horsepower ratings are available from the manufacturer. Bear in mind, however, that horsepower production usually decreases with engine wear and age.
The Addition Method
Many estimate their car's horsepower by taking the stock number and adding the amount of increase claimed by the manufacturers of performance components that have been added to the vechile. This is probably the least accurate but most common method.
Engine Dyno
This is the most accurate method of measurement, but requires that the engine be removed from the vehicle and secured to a resistance device known as a dynamometer.
Chassis Dyno
This device works the same as an engine dyno, but requires only that the vehicle be accelerated through its RPM range while strapped to a pair of large rollers.
Dragstrip Method
Engine horsepower can be calculated by indexing vehicle weight, aerodynamic drag co-efficient and top speed reached on a quarter-mile drag-strip.
Source:
Resource:
Horsepower to Trap Speed Calculator
RELATED QUESTIONS
Copyright 2023, Wired Ivy, LLC