Imagine your self driving down the road in your hot import ride with the windows rolled down, the roar of the exhaust as you press on the gas pedal; you let off the gas to here the phhsss sound of the blow off valve relieving the pressure of your turbocharger and you wonder how does it all work?
Turbos are designed with two parts, the first part is the exhaust side which connects to the exhaust manifold. Using the exhaust pressure it pushes the turbine inside the turbo which is connected to a shaft that extends to the other side of the turbo and drives the intake side. The exhaust pressure builds up (considering it has to push a turbine before it continues its journey) causing a mechanism connected or built into the exhaust side of the turbo to relieve the exhaust pressure, this mechanism is called the waste gate.
The second part of the turbo is the intake side which has a turbine that is driven by the exhaust turbine that is on the other side of the turbo. when the intake turbine is spinning it is pushing air into the engine to create more power. When the intake pressure gets to high the blow-off valve relieves the pressure which causes the phhssss sound we all know and love.
Both Turbines are connect by a shaft with bearings that allows the shaft to spin. Oil is poured in from your engine to lubricate the shaft and bearings, oil seals on each side of the shaft keep oil from going into the intake or exhaust which could cause major issues. If the oil has not been changed on a regular basis the detergents in the oil breakdown and cause "engine dirt". Engine dirt becomes very abrasive on the tight tolerance in the turbo chargers internals. Strict oil change schedules is important to the life of a turbo.
When your turbo pushes more air in the engine the cylinder also needs more fuel to create the initial higher horsepower. This is where you need to consider how big your injectors need to be, how powerful your fuel pump needs to be, installing a hotter ignition system, and of course tuning your engine. all of these upgrades wont work unless you tune the engine to push the right amount of air and fuel in the engine at the proper time to create the most horsepower. The combination of more fuel and air will need a higher spark to explode it all in you engine efficiently. The exhaust system will also need to be larger in diameter to reduce back pressure.
Heat also plays a major factor in turbo performance, this is were the inter-cooler comes in to the mix. The turbo pushes air at higher volumes which creates heat, the air flows through the inter-cooler were it gets cooled down by a process called "heat transfer". Inter-coolers transfer heat two ways, either using liquid to air or air to air. The air to air inter-coolers are the most common due to their low maintenance and cost. Liquid to air inter-coolers need more parts to operate and cost more.
The key to extending the life of a turbo is to know what to do when you have a turbo.
here are key maintenance tips to live by
- Prime your oil filter when changing oil (any drop in oil pressure due to a space without oil can cause faster wear and tear on your turbo bearings).
- Invest in a turbo timer or wait before turning your engine off (the engine needs to idle for at least 2 minutes before turning it off to allow oil to flow through and cool your turbo, if not oil will burn on your turbo bearings).
- Change oil religiously (not changing your oil on time will cause wear and tear on all parts of your engine especially the turbo)
- Keep an air filter on it (you don't want foreign objects getting sucked into your turbo causing damage to you turbine which will get sucked into your engine causing even more damage.
- Check the exhaust system regularly (Clogged converters, resonators, or mufflers create increased back pressure and raised temperature which heats up the turbo even more and can cause oil coking)
Remember if you install a turbo or purchased a vehicle with one it is important to maintain your vehicle in order to extend the life of the turbo.
Drive safe fellow tuners.