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It does seem that could be caused by a surge "bark" scenario. Is this something that "could have" happened?....For example the turbo is at 40psi and you let out of the throttle. The vanes go from open to close (or partial close) but the compressor wheel is still spinning at full speed. When the vanes close it causes turbine surge/stall (different than compressor surge) that causes the wheel to want to stall out. When the turbine stalls the compressor wheel and shaft is like a big lever that just twisted itself right in half.
It does seem that could be caused by a surge "bark" scenario. Is this something that "could have" happened?....For example the turbo is at 40psi and you let out of the throttle. The vanes go from open to close (or partial close) but the compressor wheel is still spinning at full speed. When the vanes close it causes turbine surge/stall (different than compressor surge) that causes the wheel to want to stall out. When the turbine stalls the compressor wheel and shaft is like a big lever that just twisted itself right in half.
I think you're on to the cause......Being an early adopter can have some disadvantages.
I think you're on to the cause......Being an early adopter can have some disadvantages.
This has kind of perplexed me in the past. The example below is a Ford turbo 2011+ but the newer 2017+ I believe have a similar design. The turbo itself has a Variable Vane turbine housing, it also has an internal WASTEGATE. I originally saw this a thought "why?". In the description it says it stops over speeding which usually leads to a different type of failure. Cant help to think that it could also help control spikes in EBP. My theory is based around Mechanical Wastegates that use Drive Pressure to open and close. Instant spike (short spike) in DP and the WG pushes open taking the load off the turbine wheel. Similar to how FTN was saying that a blowoff valve may be needed but on the exhaust side. Maybe an external WG set to operate off drive pressure? 6.7L Power Stroke DualBoost SST Turbocharger
Damn man that stinks, sorry to hear about everything.
will a turbonator work with an s480?
breakage is just an oppurtunity to up grade
Lol you vulture you. The one I have is for a 74mm S300 turbine so no it wouldn't fit. The have a version for 83mm S400 turbines though.
Originally Posted by brokestroke
Damn.
It does seem that could be caused by a surge "bark" scenario. Is this something that "could have" happened?....For example the turbo is at 40psi and you let out of the throttle. The vanes go from open to close (or partial close) but the compressor wheel is still spinning at full speed. When the vanes close it causes turbine surge/stall (different than compressor surge) that causes the wheel to want to stall out. When the turbine stalls the compressor wheel and shaft is like a big lever that just twisted itself right in half.
Originally Posted by brokestroke
This has kind of perplexed me in the past. The example below is a Ford turbo 2011+ but the newer 2017+ I believe have a similar design. The turbo itself has a Variable Vane turbine housing, it also has an internal WASTEGATE. I originally saw this a thought "why?". In the description it says it stops over speeding which usually leads to a different type of failure. Cant help to think that it could also help control spikes in EBP. My theory is based around Mechanical Wastegates that use Drive Pressure to open and close. Instant spike (short spike) in DP and the WG pushes open taking the load off the turbine wheel. Similar to how FTN was saying that a blowoff valve may be needed but on the exhaust side. Maybe an external WG set to operate off drive pressure? 6.7L Power Stroke DualBoost SST Turbocharger
That is an interesting idea. So are you suggesting that instead of a boost side blow of valve to let out excess air to keep it from stalling the compressor, there should be a blow off valve on the drive side to let air into the turbine to keep it from stalling once exhaust gasses have been cut off? That means the air would have to be allowed in somewhere between the vanes and the turbine so the vanes don't block the air from the blow off valve also. That's going to be hard to do without a different casting with this design I'm afraid.
Looking at the 6.7's Dualboost, the wastegate is performing its traditional role and merely letting exhaust gasses out to keep the turbine from overspeeding. This suggests to me that the vanes in that turbo lack sufficient control authority and are used for low end response only. That also means they can't close off so completely that it causes the turbine to stall. This also means I may still have the starting position of the vanes set too low.
Going along with what Brokestroke and lpzd have been discussing, could this be related to the vanes shutting too quickly (or too far) during decel. Either when you let off the throttle or when activating the exhaust brake? The thought being that the Turbonator is now suddenly trying to stop this mass of inertia.
edit:... or when you let off the throttle and the vanes close up, would that suddenly create higher drive pressure and make it want to spin faster? Maybe the source of the bark?
Going along with what Brokestroke and lpzd have been discussing, could this be related to the vanes shutting too quickly (or too far) during decel. Either when you let off the throttle or when activating the exhaust brake? The thought being that the Turbonator is now suddenly trying to stop this mass of inertia.
Yes exactly.
Today is Turbonator full degrease day to see if there is any damage hiding under all that caked on oil.
Originally Posted by RacinJasonWV
edit:... or when you let off the throttle and the vanes close up, would that suddenly create higher drive pressure and make it want to spin faster? Maybe the source of the bark?
Edit to reply to your edit: That is a good question. Are the vanes closing up so much that they cut off drive gasses and stall out the turbine? Or are they closing just enough to really spin the turbine like in the low end boost scenario? That will take data logging of the drive pressure sensor readings in the abrupt-release-of-go-pedal scenario. I'm somewhat reluctant to do that lest I break another turbo.
Lol you vulture you. The one I have is for a 74mm S300 turbine so no it wouldn't fit. The have a version for 83mm S400 turbines though.
That is an interesting idea. So are you suggesting that instead of a boost side blow of valve to let out excess air to keep it from stalling the compressor, there should be a blow off valve on the drive side to let air into the turbine to keep it from stalling once exhaust gasses have been cut off? That means the air would have to be allowed in somewhere between the vanes and the turbine so the vanes don't block the air from the blow off valve also. That's going to be hard to do without a different casting with this design I'm afraid.
Looking at the 6.7's Dualboost, the wastegate is performing its traditional role and merely letting exhaust gasses out to keep the turbine from overspeeding. This suggests to me that the vanes in that turbo lack sufficient control authority and are used for low end response only. That also means they can't close off so completely that it causes the turbine to stall. This also means I may still have the starting position of the vanes set too low.
Was thinking a standard external waste-gate that opens when the EBP has short spikes, either mechanical or driven from drive pressure.
Edit to reply to your edit: That is a good question. Are the vanes closing up so much that they cut off drive gasses and stall out the turbine? Or are they closing just enough to really spin the turbine like in the low end boost scenario? That will take data logging of the drive pressure sensor readings in the abrupt-release-of-go-pedal scenario. I'm somewhat reluctant to do that lest I break another turbo.
Definitely understand not wanting a recreation of events. My thinking process was more geared towards trying to understand what could have occurred and countermeasure as I’m sure is your direct objective.
What about adding a turbine speed sensor? The sx-e already has provisions for one. Maybe that could help you spot a problem before it causes failure as the Turbonator is being tuned in?
Was thinking a standard external waste-gate that opens when the EBP has short spikes, either mechanical or driven from drive pressure.
How does that prevent turbine stall when it's the vanes cutting off gas flow though?
Originally Posted by RacinJasonWV
Definitely understand not wanting a recreation of events. My thinking process was more geared towards trying to understand what could have occurred and countermeasure as I’m sure is your direct objective.
What about adding a turbine speed sensor? The sx-e already has provisions for one. Maybe that could help you spot a problem before it causes failure as the Turbonator is being tuned in?
You read my mind. I have been looking at BW speed sensors. They're not cheap, but then neither is breaking a turbo.