Getting more for less is always a better option. The long and the short of forced induction is why many manufacturers are choosing to boosted motor over a normally aspirated one. Whether driven by pulleys or by exhaust gases, the goal is to put more air and fuel into a motor and get better performance than another motor of a similar size.
The history of turbocharging lies with the large diesel motors of ocean liners and rail transport, as well as aviation applications of the early 1900’s. Both of these types of motors tend to run for an extended period of time at a constant RMP. Using exhaust gases to power a compressor to feed cooler air into the motor at a higher pressure is how boost is made. Initially, these low pressure turbines were used to increase fuel economy.
Fast forward through several decades of research and development, and today’s marketplace is seeing more and more forced induction motors in everyday vehicles. Keywords like “TwinPower” and “supercharged” make the marketplace more confusing than ever.
A twin scroll turbo uses the same idea of a basic turbocharger, but has a two part inflow. Splitting the input side reduces pressure differences and improves the overall operation of the system. A twin power turbo is mated to a balanced exhaust manifold to aid in keeping exhaust pulses at equilibrium and not siphoning power out of the adjoining cylinder. Many newer BMW engines use this setup.
High performance motors such as those found in the V8 bi-turbo powered BMW’s and Mercedes-Benz AMG’s are set up in a “Hot V” configuration. Traditionally, V motors have the intake in the center of the V and exhaust out and down. This is reversed in a “Hot V”, so the supercharger or turbochergers can be placed there. Additionally, this design is more compact and can allow these motors to fit into smaller engine bays or into a cross platform chassis where a larger motor couldn’t fit.
The Audi 3.0L V6 “supercharged” motors feature an Eaton 1320 supercharger. These superchargers work in the same manner as their turbocharged counterparts, but are driven from the motor itself. Supercharging offers a more instantaneous response since it does not suffer from lag.
In today’s world: car motors are being produce lighter by using alloys over heavier cast iron; stronger by better material use like forged internals and titanium valvetrains; more powerful via forced induction. All of this helps us go further on less.