Quote:
Originally Posted by Wanted_M
Would be nice if a true metallurgical RCA was performed not an assumption to truly understand what caused the failure. Was it impacted by rub, LCF or HCF?
That's what we do with our gas turbine blading, a good idea would be to integrate a speed sensor into your compressor housing so tuners know the limit based on your maps. Do you have maps for your compressor/turbine wheel as I've never have seen one?
Typically operating speeds are around 100,000 to 250,000 rev/min, depending on wheel size. Maybe take a peek at the turbo serial #, verify VSR and see if anything was out of balance for higher compressor/turbine speed. As good practice, it would be beneficial to offer the VSR report should the buyer asks for it.
My .02C.
|
We do not bring any turbo system to market without speed sensor testing data. All our prototype turbos utilize speed sensors for data collection to ensure shaft speeds stay within the adiabatic efficiency of our compressor wheels. Attached below you'll see an example of a speed sensor installed one one of our prototypes. We also don't provide compressor maps as we do not manufacture universal fit turbochargers. Companies that manufacture universal turbochargers provide this data so the end user can decipher which turbocharger is most efficient for their goals and vehicle application. Our Engineers design each turbo system specific to the vehicle application and therefore all the guess work is taken out of the equation. Also, the horsepower figures we advertise are directly based off of the flow capabilities that our rotor group has the ability to support. All this information has been provided before in previous online discussions about our turbo systems. To this day, we have yet to see any company sellling their own oem fitment turbochargers hybrid or otherwise that offer maps for their compressor wheels.
Operating speeds for turbochargers that utilize our frame size are nowhere near 250,000 rpm. In addition, no ball bearing technology could ever support those types of shaft speeds. Also, vsr balancing doesn't work in the manner you're describing. All our turbos are balanced below 1g via a Schenck balancer and the data for each serial number is then cataloged for internal purposes. In addition, a turbo that is balanced at low shaft speeds and out of balance at high shaft speeds will look like a dyno graph on the vsr screen. A balance that continues to climb as shaft speed climbs, even within range, is never an acceptable practice. A correctly balanced rotor group should either be flat or have a downward slope as shaft speed increases. This method also helps reduce vibration during overspeed conditions. Having said that, there is no need for us to go back to confirm if there was any balancing issue with a specific serial number. If a turbocharger doesn't pass our balancing requirements it is never shipped out. In the hypothetical scenario that a turbocharger was shipped out of balance, it would fail almost immediately at wot with this type of boost level and not 1000 miles later. Lastly, a balancing issue would not cause the turbine inducer to break off blades in an empty cavity unless the turbine wheel broke off the shaft making contact with the housing which did not occur.