Quote:
Originally Posted by PoorMans180SX
Yeah the 7163 is actually has very similar wheels to the 7064 (obviously from the names) so it will probably flow in the 55lb/min range. Pretty nuts when you consider the spool.
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Is that a safe thing to assume? The mixed flow turbine seems like enough of a departure from convention that a 63mm mixed flow isn't going to consume air in the same way a 64mm radial turbine will. Compressor sides are nearly identical though.
Also, I'd like to see BW take their turbine wheels down in size a little; I'm curious to see how that would affect things. Currently BW has their turbines 5-10mm larger than the comparable Garretts and there are a few things to consider with that. They can make a larger wheel than Garrett and still have the same mass. The problem is that it's inertia that keeps the wheel from moving, not mass and inertia increases linearly with mass but squared with radius. So by increasing the radius by 5-10mm over Garretts they might actually be winding up with a higher inertia even though their wheels weigh less. This however is offset a bit because when you increase the radius of the turbine wheel, you're also increasing the torque arm length for the force of the exhaust acting upon it, making it easier to rotate.
There are a lot of things to consider when sizing the turbine, especially when working with a new material that provides a mass decrease. I'm sure BW has done their homework and are certainly smarter than me but I still think it would be interesting to see something like a 7158 or 7155. That ought to flow like a GT2871 but spool like a T25.
Mind you, this is all in terms of their "old" 1st generation EFR turbines. This new mixed flow wheel changes things.