Turbochargers: Unraveling the Mystery Under Your Bonnet

More new cars are coming equipped with turbochargers...but what are they?

Cast your mind back about a decade, the only time you would hear about a turbocharger was if you were lucky enough to drive the top of the range model, like a Golf GTi, drove a turbo diesel or you enjoyed the modified and custom car scene.

Fast forward to the last several years, and now more cars are being fitted with turbochargers from the factory, even the smallest models as manufacturers try to gain as much power and torque as possible out of small capacity motors while retaining their fuel efficiency. Take the Hyundai Venue, which is equipped with a 1.0 turbocharged engine or the 1.0 turbocharge Renault Kiger.

But what is a turbocharger, how does it benefit your engine and what can you do to maintain yours? Well, that’s what ClickaCar is here to help you with.

What is a Turbocharger?

In its most basic form, a turbocharger is an air pump. A turbocharger unit consists of two housings that contain two propellers, or wheels facing the openings on either side.

The turbocharger itself is attached to the exhaust manifold of your car and uses the waste exhaust gasses to spin the exhaust wheel, like a steam-powered turbine. This exhaust wheel spins the shaft that connects it to the wheel on the other side, known as the intake wheel, this draws in air.

So How Does a Turbocharger Benefit My Engine? 

Now that you know how the turbocharger gets spinning thanks to your engine’s wasted exhaust gas, how does it benefit your engine? 

If you know anything about combustion, you will know that more air plus more fuel gives you more heat, and therefore energy, like when you use a hairdryer to ignite the coals in your braai. The turbocharger forces more air into your engine allowing the engine to create a bigger explosion on its combustion cycle and hence, generate more power.

The higher air pressure which a turbocharger forces into your engine is known as boost, and it is measured as a percentage above the atmospheric pressure of the air around you. This is usually measured in PSI or Bars.

Factory turbocharged cars run a very low boost setting which maximises reliability, power output and fuel efficiency. With a turbocharger, a 1.0 engine can produce more power than a 1.6.

How To Maintain Your Turbocharger?

A turbocharger is a very expensive piece of equipment and despite most warranties covering turbochargers, replacing one after your car’s service plan has ended will take a serious bite out of your budget. To help you ensure this doesn’t happen, there are a few simple precautions you can take.

Let The Engine Warm Up

The bearing which suspends the shaft between the two turbo propellers endures massive RPM loads and needs to be well lubricated. When you start your car, oil begins pumping around your engine and begins feeding into the turbocharger, once the turbocharger has enough oil around the bearing at the right temperature, then you can begin driving at a higher RPM.

Let The Turbo “Wind Down”.

If you have been driving your car at sustained speeds, then you cannot simply turn off your engine when you arrive at your destination. This is because your turbocharger is still spinning and as soon as you turn off the engine, the oil pump will stop feeding the turbocharger, resulting in the bearing “running dry”. It’s recommended that you idle your car at low RPM for a minute after driving to allow the turbo to stop spinning.

Regular Oil Changes

A turbocharged car requires oil changes more regularly than a car without one, and you need to ensure that the oil level is kept at the required level. The car’s service manual will give a suggested mileage as to when the oil must be changed, but as the car gets older, it's better to carry out the oil services more regularly as a precaution. 

Keep Your Cool

Most, if not all turbocharged models come equipped with an intercooler, this is a heat exchanger which helps to reduce the temperature of the air going into the engine. Some cars use a simple air-to-air intercooler which works the same as a radiator without any water in the system. Most high-performance models use a water-based cooling system which forms part of your car’s radiator system. 

Whichever system your engine uses, it's best to make sure that it is well maintained and not blocked.

Keep It Clean

Your car’s turbocharger spins at extremely high RPMs and even the most minute particle of dirt can “sandblast” the internals. 

To avoid this, ensure that you use a good quality air filter and have it changed regularly. A low-quality air filter won’t only let dirt past but can also begin disintegrating and lead to further damage as particles get sucked in by the turbo. 

Boost Creep

Aside from the turbocharger, the entire system uses several other components to ensure that everything runs correctly, the two most important items are the dumpvalve or recirculation valve, and the wastegate.

The dumpvalve or recirculation valve will release the pressure created by the turbo when you take your foot off the accelerator to prevent the excess boost from damaging the turbocharger. The wastegate keeps the boost pressure at a consistent level in line with manufacturer specifications.

If the boost levels suddenly spikes or you lose pressure, then these components may be at fault and it's best to have them checked by a mechanic. Sustained loss of boost or uncontrolled boost spikes will damage your engine.

Turbochargers have remained a mystery for many people outside performance circles, or the racing scene. But as they become more mainstream in our daily cars, knowing how they work and how to maintain them will ensure that you enjoy your car for longer, while preventing costly damage. 

Do you want to experience turbocharged performance yourself? Visit the ClickaCar Virtual Showroom and find a turbocharged model.