Turbo charging vs. Supercharging

[Induction Concepts]

Breaking a turbine blade will only spit it out the exhaust system because the turbine is the exhaust side and completely separate from the compressed air side that goes into the engine.

Having a compressor blade failure is about as likely as getting struck by lightning, well, probably less likely, I mean if you play golf during a storm, or climb a 200ft metal pole like a cell phone tower, your chances are pretty good. Can it happen, sure, primarily on race cars that don't run air filters and FOD gets sucked in and fractures a compressor blade.

Even then, the particle would have to make it out of the housing itself, down some charged air tubing with bends, a couple of feet minimum usually, then make it through an intercooler, then through more charged air tubing, usually with several more bends, then through the throttle body, through the intake, and past a valve. Have you ever looked at the inside of an intercooler, the air passages are very tiny, most likely the piece would get hung up at this point.

Can it happen, sure. Can a pig fly? Sure, if you've got a big enough sling-shot.

What the whole point is, is how dependable are these systems under normal operating conditions. And for turbos, racing and hundreds of thousands of miles on semis is considered normal operating conditions. The answer is they are extremely dependable and a proper turbo system should out live your engine. It only needs quality oil, regular oil changes and a good air filter. How many daily drivers do you know of that have 300,000 miles on them before an engine rebuild, like over the road semi's? Pulling a very heavy load, through extreme heat, cold and precipitation their entire lives.

If dependability was even the slightest bit in question, they wouldn't use them, period. Maintenance costs on a semi can make or break a trucking company. They must have dependable, reliable vehicles to stay in business.

Same thing for aviation. They are used for their reliability. Aircraft are the most heavily regulated means of transport on the planet, second only to spacecraft. When cars crash, the fatalities are none, or few. When planes crash, it can be hundreds. Every aspect of anything to do with the FAA is heavily regulated, inspected and maintained. I have a shop that does some machine work for us. They are also an FAA certified repair station. They have to keep their scrap separated logged and inventoried for several years, so that if there is ever a problem, they can trace information all the way back to the actual left-over scrap metal that was used, even down to individual lots or batches of the same metal alloy.

A failure can happen to any component, pistons, rods, valvetrain, crankshaft, oil pump, axles, brake calipers, you name it. Turbos are designed and manufactured to much higher tolerances and quality standards than our engines are. They have to be because of the heat and speed that is their daily life. They also use exotic alloys like inconel.

A wastegate failure is practically unheard of also. Again, can it fail, sure. Will it, almost certainly not. You are much less likely to have a turbo or wastegate failure than you are to have an engine or transmission failure. Again, semis and aircraft wouldn't use them if there were any questions about dependability or reliability.

Some turbos do use coolant to aid in cooling. Not all of them do, many OEM turbos don't. All of ours use coolant. We specifically request the water cooled center cartridges. This helps to remove the heat from the center cartride so that the oil doesn't coke on the bearings, after the engine is shut off, ensuring a long happy life. It doesn't add a noticable temp increase to the coolant though. If the cooling system is in good working order, you shouldn't see a noticable difference on the temperature gauge. Same thing for the oil. It will temporarily increase the temp as it passes through the center cartridge, but the heat quickly dissipates. If it didn't, in any stock engine, the oil that is splashed on the valvetrain, underside of the piston, and the cylinder walls, scraped off by the rings, would just continue to build heat until the oil broke down and lead to catastrophic engine failure. It's amazing to TIG weld on a piece of stainless and see it glow red hot, then pass just a little bit of water over it, for just a few seconds, and it is cool to the touch. Liquid has excellent thermal transfer properties.

Also, turbos don't create heat, other than that created from the compression of the charged air, but we're only talking 200-300 degrees normally on that side. They do retain the heat of the exhaust system, which is where their heat comes from. So they aren't any hotter than your headers. Remember, the exhaust is just spinning a turbine wheel. And with the advances in thermal barriers, you can keep a great deal of heat inside the turbine housing and tubing. For instance we use a special 2000 degree thermal barrier coating from Jet-Hot (not the 'sterling') on all of our turbine housings. It provide a 25% drop in surface temperatures with a single application. This same coating can be applied to the inside and outside of the tubing.