Quote:
ORIGINAL: Fallstar01
Whipple:
--Ford GT's supercharger has a Compressor from Whipple
<--stuff removed-->
The Eaton is referred to as a "Roots" supercharger and the most common compressors on ford engines are the M90 and the M112. Oddly enough, it's screws look much more like twins than the twin-screws.
<--stuff removed-->
Eaton/Roots:
|
All good information, and you even help to explain the twisted history of the screw compressor (no pun intended), even though I still don't fully understand it.
I have three picks here with some points you made above:
1) The Ford GT's Supercharger *is* in fact assembled by Eaton. The rotating group might have components sourced from Opcon/Autorotor/Lysholm or maybe even Whipple, but the Ford GT supercharger was designed by Eaton engineers, tested by Eaton and manufactured by Eaton. Eaton licenses the screw compressor design and has the right to manufacture and sell them. Why doesn't Eaton sell more screws? Most OE manufacturers still choose the Eaton Roots design over the screw compressor due to cost, reliability, availability, NVH, and low power consumption at cruise due to the lack of internal compression.
2) The rotors of an Eaton are not twins. The image above is very misleading. Eaton superchargers in fact have a left and a right rotor that are mirror images of each other. I think if you'd have a tough time spinning the example of the Roots blower shown above.
3) The diagram referenced above is in fact of a "Roots" compressor, but not an Eaton Roots. Even so, it is incorrect for a plain old Roots. Lets imagine the rotors were correct and that you could actually spin the rotors in the direction shown above. With the rotors moving in the direction the arrows point, the inlet and outlet would be reversed (i.e. "fill side" on bottom, discharge on top). The air travels along the OUTSIDE of the case and then it is discharged as the rotors begin to mesh and the air reaches the discharge port.
What makes the compressor above not an Eaton? Eaton superchargers all have "axial" inlets similar to a screw as they draw air into one end and then discharge air out the top or bottom (depending on orientation).
As for KnotBand's comment: Roots and Screw compressors are both positive displacement compressors. Each revolution they take, they will move a fixed amount of air equal to their displacement (at least in a perfect world, since alot of other things come into play like inlet restriction, clearances, etc). A centrifugal compressor is not a positive displacement compressor since the volume of air it moves is not fixed and varies greatly with RPM.