RPM and Tip Speed Limits

and here's another here's another shortcoming of ball bearing turbo chargers okay you need a ball bearing turbo charger uh on an eight millimeter shaft so something like gt28 size or you know like 300 horsepower per turbo kind of size that's that sort of size range okay um that rotor group the the diameter of that those rotors that rotary group the compressor and turbine is very small okay and the speed is very high see so we don't talk about like there's a rpm limit for uh for the turbos we talk about there being a tip speed limit for the turbos because this is the the magnitude of that tip speed that decides whether or not the part is going to explode you know you if you got a cast iron flywheel they explode sometimes right you rub them up too high yeah yeah well that's because you exceeded the structural the limit of the part uh just from the geometry on it based on the material it's made out of you spun it fast enough to explode it actually happens with anything okay you explode the cd-rom if you spin it fast enough there's some neat videos of that on the internet too but things that spin explode if you spin them fast enough there's no exception to this anywhere yeah uh you know it's just funny was like sometimes people are confused with my reaction they call me go hey man robert man one of these turtles just popped and i'm like okay you're not surprised like am i surprised that you could explode a turbo no i'm not explaining no it's quite possible to do it you know there's a number of ways which you can you know cause that to happen uh prematurely or unintentionally and not even be trying boost leaks easiest one yeah well you get a boost leak what's the first thing somebody does well let me just they don't know it's a boost leak right for some reason i just it's not making the same boost it used to what's the first thing you're gonna do man you flip that laptop up and you got to go duty cycle up arrow up up arrow okay what you just did was take the thing that was already trying to meet a target pumping through the engine and the leak and now you said now pump more through the leak you know it it it does it does until it explodes you know and people go i was only running 20 pounds of boost i don't know how i could overspeed it maybe there's a torn coupler maybe there's an intercooler that's got a weld broke on it maybe you haven't found it i've checked everything if you'd have checked everything you wouldn't be calling me asking me what's wrong you'd…