How do they work?
Turbos are formed of two main parts – a turbine and a compressor. These are linked so, when the one spins, the other spins with it. As fuel in the engine is burnt, exhaust gasses are forced out of the engine at high pressure, down a snail-shaped tube to spin the turbine. This turbine spins at incredibly high speeds (up to 250,000 rpm) and causes the compressor (effectively a reversed turbine) to spin. This sucks significantly more air into the engine than a normally-aspirated (non-turbo) unit, making more power.
Turbos run at immense speeds which means they operate under huge pressures and temperatures. Typically, an intercooler is paired with the turbocharger to cool the hot air coming out of it and an oil cooling system ensures the turbo itself doesn’t run too hot. Diesels, having tougher engine blocks and simpler intakes, are ideally suited to being turbocharged so all modern diesels have them.
What are the benefits?
More power is the glaring headline here, but it’s far from the only advantage. Turbo engines can make the same power as a normally-aspirated engine while using less fuel. Hence why Ford, for example, has replaced the old 1.6-litre petrol engine with a new 1.0-litre turbo it makes the same power but uses much less fuel.
Turbos also give engines more torque often lower down in the rev range. This means they feel much stronger around town where the extra torque makes nipping into gaps easier. Another, unexpected, advantage is that turbos actually make for a quieter engine as they muffle the sound of the intake.
Any downsides?
Not many, which is why they’re so common in engines now. Mainly, they add cost and complexity to an engine becoming just another part to go wrong and, with the high temperatures and pressures they operate at, when they do, it’s often in quite a spectacularly expensive fashion.
There’s another thing. Reviewers often talk of turbo lag -a brief delay between pressing the throttle and the engine making power. This is caused when the exhaust gasses are not at the required pressure to spin the turbine optimally, hence the delay as the turbo comes "on boost". Car makers try to mitigate this by using more smaller turbos instead of one big one, turbos with multiple optimum operating speeds or, for some race cars, a fearsome anti-lag system that causes 10ft flames to shoot out the back of the car!
Careful control of the throttle in a turbo car is required if you want to get close to the claimed efficiency figure turbos are efficient when cruising "off boost" (ie when the turbo isn’t really working) but very inefficient when "on boost". This means that you may need to alter your driving style if you’re coming from a non-turbo car.
Turbos are formed of two main parts – a turbine and a compressor. These are linked so, when the one spins, the other spins with it. As fuel in the engine is burnt, exhaust gasses are forced out of the engine at high pressure, down a snail-shaped tube to spin the turbine. This turbine spins at incredibly high speeds (up to 250,000 rpm) and causes the compressor (effectively a reversed turbine) to spin. This sucks significantly more air into the engine than a normally-aspirated (non-turbo) unit, making more power.
Turbos run at immense speeds which means they operate under huge pressures and temperatures. Typically, an intercooler is paired with the turbocharger to cool the hot air coming out of it and an oil cooling system ensures the turbo itself doesn’t run too hot. Diesels, having tougher engine blocks and simpler intakes, are ideally suited to being turbocharged so all modern diesels have them.
What are the benefits?
More power is the glaring headline here, but it’s far from the only advantage. Turbo engines can make the same power as a normally-aspirated engine while using less fuel. Hence why Ford, for example, has replaced the old 1.6-litre petrol engine with a new 1.0-litre turbo it makes the same power but uses much less fuel.
Turbos also give engines more torque often lower down in the rev range. This means they feel much stronger around town where the extra torque makes nipping into gaps easier. Another, unexpected, advantage is that turbos actually make for a quieter engine as they muffle the sound of the intake.
Any downsides?
Not many, which is why they’re so common in engines now. Mainly, they add cost and complexity to an engine becoming just another part to go wrong and, with the high temperatures and pressures they operate at, when they do, it’s often in quite a spectacularly expensive fashion.
There’s another thing. Reviewers often talk of turbo lag -a brief delay between pressing the throttle and the engine making power. This is caused when the exhaust gasses are not at the required pressure to spin the turbine optimally, hence the delay as the turbo comes "on boost". Car makers try to mitigate this by using more smaller turbos instead of one big one, turbos with multiple optimum operating speeds or, for some race cars, a fearsome anti-lag system that causes 10ft flames to shoot out the back of the car!
Careful control of the throttle in a turbo car is required if you want to get close to the claimed efficiency figure turbos are efficient when cruising "off boost" (ie when the turbo isn’t really working) but very inefficient when "on boost". This means that you may need to alter your driving style if you’re coming from a non-turbo car.