Since the creation of the internal combustion engine, finding ways to generate more horsepower, kilowatts and torque from them has been forever evolving.
So, let’s break down these terms and what they represent in an engine.
Horsepower: This is a measurement or a rate at which work is done and customarily used to reference the output of engines and motors. The term was adopted by a Scottish engineer, James Watt. He was determined to compare the output of a steam engine to that of a draft horse. So, with a bunch of mathematical equations, he worked out how many horses it would take to get the same output as the steam engine. Therefore, we have the term Horsepower.
Kilowatts: Modern-day measurement of the horsepower saw them convert the output into
Watts, and by definition, 1 Kilowatt equals – 1000 Watts, 1 HP equals 0.7457Kw.
Torque: Referred to as a moment of force. It is said to describe the moment of change of angular momentum imparted to an isolated body. It was Archimedes who used levers to push and pull a linear force applied to a body. Torque can be considered a twist of an object relative to a chosen point. A few mathematical equations later, we have a measurement for torque, usually measured in Foot Pounds Ft-lb and now commonly measured in Newton Meters Nm.
How do we generate more power (insert video of Tim the Toolman grunting)? With modern-day advances in Electronic Fuel Injection, finding or delivering more power from an internal combustion engine, can be very simple but, at the same time, very complex.
When your motor vehicle was initially designed and built, an engine map was loaded into the Electronic Control Unit (ECU): the map tells the engine when to fire injectors and or ignition coils, how to adjust the Variable Valve Timing (VVT) and in some cases when to shut down cylinders to increase fuel economy. All this and more is happening inside the ECU; it sends and receives information from sensors all over the engine and transmission to give you the optimal driving experience required to enjoy driving your car.
By adjusting the engine map, we can move the timing at which the engine fires and how much fuel it can deliver, adjust valve timing to stay open longer or shorter, take away throttle lag in the throttle pedal and throttle body, adjust transmission shifting, and loads more variables. Some performance gains will require modifications to the engine, which your desired outcome will determine. You may want to be able to run a race-defined fuel like E85 and a pump fuel like ULP98; if this is the case, for example, you may require a fuel system overhaul to be ethanol-compatible.
Other mechanical upgrades maybe tuned-length exhaust headers, high-flow catalytic converters and tuned exhaust systems, and cold air induction with an air filter with high flow capability. In looking for a much higher increase, you may want to upgrade to a supercharger or turbocharger used to force the air into your engine, resulting in much higher power increases.
All of the above is relative to petrol fuel-injected vehicles. What about modern-day diesel?
The modern-day diesel is no slouch; technological advances, like the petrol engine, have also evolved. Once a diesel engine was a true workhorse, they loved to load and lug along, being
able to generate high torque at low RPMs. The slow burning of the diesel fuel combined with a long stroke in the diesel engine delivered that torque.
Now, to deliver a more efficient diesel engine, I will go out on a limb and say there would be a few that do not have a turbocharger attached to them. The ability to squeeze more diesel and air into the combustion chamber gives the engine more power, much quicker and can run more efficiently. The turbo provides each cylinder with as much filling as allowed, and the Common Rail Fuel Injector sprays a high-pressure atomised diesel that mixes with that squeezed-in air to create the firepower the engine requires.
How do they increase the power of these engines? Like the petrol engine, the ECU has a map set out by the manufacturer. The relative tuner can adjust the map to change the timing of componentry in the machine, allowing more turbo boost, opening the injectors for longer to deliver more diesel and changing a few signals to and from the ECU on select sensors around the engine bay.
You may need mechanical upgrades as well with diesel tunes, and typical upgrades include larger diameter exhausts to assist in letting the exhaust flow much better, cold air induction like snorkels, larger surface intercoolers and, in some cases, depending on your desired outcome, bigger common rail injectors and turbo upgrades.
Consider more upgrades to drivelines and brakes for petrol and diesel power increases. Talk to your preferred tuner about these upgrades, and they can suggest what will work for