Why Remap A Car?
What is BHP?
Brake horsepower (BHP) is the measure of an engine’s horsepower before the loss in power caused by the gearbox, alternator, differential, water pump, and other auxiliary components such as power steering pump, muffled exhaust system, etc. Brake refers to a device which was used to load an engine and hold it at a desired rotational speed. During testing, the output torque and rotational speed were measured to determine the brake horsepower. Horsepower was originally measured and calculated by use of the “indicator” (a James Watt invention of the late 18th century), and later by means of a De Prony brake connected to the engine’s output shaft.
More recently, an engine dynamometer is used instead of a De Prony brake. Although the output delivered to the driving wheels is less than that obtainable at the engine’s crankshaft, a chassis dynamometer gives an indication of an engine’s “real world” horsepower after losses in the drive train and gearbox. This gives a reasonably accurate indication of how a wheeled vehicle engine will perform once on the road.
What is Torque?
Torque is the twisting force created in an engine by rotating parts; horsepower is the measurement of how fast torque is being used. Horsepower and torque work hand-in-hand, as horsepower is calculated from torque.
For the average buyer, torque shouldn’t be a deciding factor unless you know you’ll be towing or hauling heavy loads. And that’s where high-torque vehicles will do well, driving while towing a trailer or maxing out cargo capacity. It will be easier to accelerate and sustain speed with a high-torque car in any situation, but especially with heavy loads.
High performance cars can also produce gobs of torque that greatly aid in acceleration. That feeling of your eyeballs being sucked into the back of your head in a fast car during heavy right-foot pounding is an example of excessive torque.
What is NM?
A newton metre is a unit of torque (also called “moment”) in the SI system. The symbolic form is Nm or N•m. One newton metre, sometimes hyphenated newton-metre, is equal to the torque resulting from a force of one newton applied perpendicularly to a moment arm which is one metre long.