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I've been researching turbo blankets and found mix reviews, many of which still recommend one given some possible long term adverse effects

-Has anyone had a turbo blanket on their 2013 Gene for more then a year?
-Should they be swapped yearly?
-What are the possibilities of a turbo blanket cracking the housing?

My understanding is that trapping heat in the turbine is good, expanded hot gas spools faster. And keeping the radiant heat from the CHRA and compressor housing is a very good thing (although heat will still transfer through the metal contact).

Caz
 

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Are you speaking of blanketing your stock turbo?
 

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From when I asked GCP back when he was testing out building O2 housings, he mentioned that wrapping the turbo or exhaust parts is a super bad idea due to it holding the heat on the parts. While it is good for other surrounding parts not to get as hot, the turbo and exhaust parts will tend to overheat under racing/hard driving conditions and may lead to failures/leaks/breaks.
 

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Racing conditions vs DD driving. There is a common misrepresentation that turbo blankets reduce a turbo's life due to heat soaking of the parts. While there may be a little bit of truth to that in that it does keep the heat in, think very hard about what your turbo is designed to do.

By it's design a turbo has hot exhaust gases running through it and gets very hot as a result. In other words, run a turbo hard and it will get heat soaked because hot exhaust is heating the metal surfaces. If you remove the heat source (the exhaust) the turbo does not get any hotter as a result. Heat actually benefits the operation of the turbo to a certain extent because hot gases tend to turn the turbine faster than cool gases. If the hot exhaust gases cool when it passes through the turbo, the turbine loses efficiency. You want to keep the hot side hot while it is operating.

What about when the turbo is not operating? Heat soaking the bearings (journal or ball bearing) of the turbo shaft is not necessarily a good thing as this promotes coking of the lubricating oil and can lead up to a build up of carbon in the bearing. This can happen with or without a turbo blanket by the way. While a blanket may prolong the time that the oil sits in the heat it really has a negligible effect on the overall process. The only real way to cool the turbo is to allow it to cool naturally by idling the car after the turbo has been pushed really hard and not let the oil in the turbo sit and cook. Again, this is true with or without a turbo blanket. A turbo blanket will not increase the amount of time that car must idle to cool the turbo down to a safe level.

So, if idling will cool the turbo and reduce the chances of coking, why has Hyundai (or any other car manufacturer of turbo cars) set a turbo timer that prevents the car from being shut off until the turbo has been properly cooled? Two reasons:

1. Hyundai assumes all drivers to be complete idiots and as a result, designed their cars to be as idiot-proof as possible. There is another assumption that they make, and that is that the average driver does not "race" their car... in other words, they don't spend all their time driving around with the turbo in full spool for extended periods of time. Time spent at lower RPMs in traffic have the same result as idling the car. Yes, the turbo gets hot, but not nearly as hot as when it is sucking in huge amounts of exhaust at 4000+ RPM.

2. Oils have gotten a lot better and contain additives that resist coking. Synthetic oil can literally sit and cook for hours before any noticeable coking occurs... if it occurs.

So, given that a turbo blanket really has relatively minimal impact on heat soaking, let's discuss why it's good to keep the hot side hot:

  • First, a turbo blanket protects components within your engine bay. The turbo blanket isolates the heat produced by your turbocharger, and prevents that heat from damaging, or even igniting, components surrounding the turbocharger within your engine compartment, such as plastic and rubber hoses and electrical wiring, as well as painted surfaces, such as the engine bay and the surface of the hood. Also, it prevents areas of localized high temperature from damaging the engine itself. For example, a common cause of head gasket failure in turbocharged vehicles is localized heating of a portion of the engine. The heat differential between the portion of the engine near the turbocharger and the rest of the engine can cause warping of the head, and thus, head gasket failure. This has been a known cause of head gasket failure in both OEM and aftermarket turbocharged vehicles.
  • Second, a turbo blanket improves the performance of your turbocharger by keeping "the hot side hot." In keeping the exhaust gases within the turbocharger hot, turbocharger efficiency is improved. As you may know, the hotter a gas is, the more expansive it is. Within a contained system of a specified size, the more expansive a gas is, the greater the pressure derived and thus, the greater the flow of gas to escape the containment. With this increased pressure and flow rate for a given engine RPM, the acceleration of the turbocharger's impeller is increased as compared to the same turbocharger with the engine at the same RPM but with cooler exhaust gases. This equates to faster spool up of the turbocharger, as well as greater attainable levels of boost. What a driver will experience with a turbo blanket is greater turbocharger responsiveness. The faster spool up of the turbocharger means less turbo lag and a more linear power curve.
  • Third, a turbo blanket improves the performance of your turbocharger by keeping "the cool side cool." As you may know, it is very important to keep engine intake air cool. This is why intercoolers are often utilized with turbochargers. Similar to above, the cooler a gas is (such as intake air), the more dense it is. The more dense the intake air, the more oxygen it contains per unit volume. The more oxygen reaches the engine, the more power can be obtained. In keeping the heat of the exhaust gases contained within the hot side of the turbocharger and away from the cool side of the turbocharger and the intake path, more oxygen per unit volume reaches the engine, and thus, more power.
So... to summarize:

  1. You do not need a turbo blanket on an OEM turbo. Hyundai designed the heat shields to prevent damage to surrounding components.
  2. You do need some kind of barrier between the hot side of the turbo and plastic/rubber engine components when there is no heat shield between those components (i.e., when you upgrade your turbo to an aftermarket option with no heat shield option).
  3. Keeping the hot side hot and the cold side cold is a good thing. The hot side of the turbo works more efficiently when the heat is kept inside of the turbo. Likewise keeping the hot side from residually heating the cold side improves the efficiency of the turbo compressor.
  4. You can put a turbo blanket on an OEM turbo with little or no adverse impact; however, you will probably not notice any positive impact either.
  5. You do not have to idle your car after normal DD driving to cool the turbo off. Hyundai already assumed that you weren't going to do it and you're just wasting gas and polluting the environment for no good reason.
  6. If you race your car until your turbo glows red hot and then shut the engine off without allowing your turbo to cool down, you are probably a fool who shouldn't be racing a car at all. "Race" for the purposes of this discussion can be defined as extensive operation of the engine at high RPMs and pushing the outer boundaries of its limitations.
Hope that clears some things up and hopefully puts to bed some myths.
 
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