Need For Speed: What Makes One Car Faster Than Another

Posted on 30 June, 2009

Although speed demons can’t do much for their higher auto insurance rates, that doesn’t stop them from marveling at the fastest cars in the world. But what makes one car faster than another? It essentially comes down to maximizing horsepower.

Horsepower refers to an engine’s strength. This is how drivers can accelerate to high speeds in a matter of seconds, carry loads of various weights, and stop in mere moments. The fastest cars accelerate to a given speed in the smallest amount of time and are able to stop immediately. A typical car usually has a 120-horsepower engine, while the fastest cars can have up to an 800 or more horsepower engine. There are a number of features that engines can have to maximize its horsepower.

The more cylinders an engine contains, the greater performance it will exhibit. When an engine has more cylinders, it has more pistons to pump and turn the crankshaft, leading to combustion and powering the engine.

When air is allowed to enter the engine more freely, the pistons of the engine are able to work more efficiently. So a car with a large air filter or smaller intake piping will be faster than an engine with a smaller air filter because more air is being filtered in the same amount of time. Also, cars with polished or smoothed intake manifolds decrease air resistance, allowing air to flow in much easier. More intake and exhaust valves also mean greater airflow.

Cars with an intercooler radiator are able to decrease the temperature of the incoming air, therefore contracting it and allowing more of it to run through the cylinders and in turn, increasing horsepower the cylinders can churn out. Turbo chargers also pressurize incoming air and allow more air to enter so that the pistons can go to work more efficiently.

A high-performance exhaust system makes a car faster because it allows the exhaust to exit freely, instead of backing up, which makes an engine lose power. High-end systems have a header, free-flowing mufflers, and large tail pipes. These help exhaust move out from the engine and reduce air resistance.

Weight and Design
But the engine’s power isn’t the only thing that makes one car faster than another. Lighter cars with a lower weight to haul around help engines perform better. Therefore, if two cars are identical in every way, the weight of the driver can be a factor in determining which one will be faster. Lightweight parts take less energy to function and enable the engine to rev up faster.

The sleek and stylish designs of the fastest cars in the world aren’t all just for looks and admirable glances. The design of the body does serve a significant purpose when it comes to speed. The sleeker the car is, the less air resistance it faces. Faster cars have streamlined, rounded bodies that cut through the air like a warm knife through cold butter. Therefore if two cars with identical engines were to race, the one with the sleeker design might win out.