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The biggest killer of these turbos is not letting them cool-down. Most turbos use floating bearings, which means theres oil on the outside and inside the bearing. Also provides dampening to the shaft harmonics. Our bearings are non-floating, they're pinned in place and oil is only on the inside of the bearings. My theory on why is beacause with a vnt turbo, you can have high shaft speeds at low engine rpm. Because the oil pump is driven by engine rpms, low engine rpms = low oil pressure. Journal bearing turbos need pressure to work as designed, having high shaft speed and low oil pressure would wreck bearings fast. Floating bearings require more pressure and flow since there is oil on both sides, where fixed bearings need less oil press/flow cuz there is less than half the surface area to keep lubed. Again, this is my theory. Where this matters is cool-down. When you shutdown heat travels from the exhaust wheel and through the shaft. Floating bearings have more oil around to soak up the heat, they can still be cooked, it just takes more. Also when these cook, the bearings will be stuck to the shaft, but because they float in there bores, they are still able to spin. Only they are spinning at the same speed as the shaft. This is fine at idle, but one the turbo spools the brass bushings cant take the g-load, expand, touch the housing, and then carnage. Fixed bearings have very little oil to soak up the heat. What is there is heated up faster and hotter. Once its cooked, the shaft has no choice but to spin because the bearing is fixed in its bore. Wherever the highest point of friction is it builds up heat until the shaft fails. This is why almost all turbos now are watercooled. The water cooling is not meant to do any kind of cooling while it runs, its only there to absorb heat after a shutdown. All of garretts new vnt turbos are watercooled, hmmmm coincidence??
_________________ 05 Liberty Limited CRD, converted to KPA 2863 ball bearing and billet turbo, 50hp injectorsl, complete egr delete, cooling fan delete, weeks intake kit, cummins in tank lift pump, ARP studs, 3" turbo back exhaust, samcos, etecno plugs, GDE trans tune, custom GDE engine tune.
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