What stall speed for PT??

[Steve Chryssos]

Made obsolete by: CFD software design, electronic transmission control, Overdrive, Lock Up clutches and--believe it or not--disc brakes.

Originally designed for high torque, big heavy cars with drum brakes to prevent "creeping" at stoplights and to try and improve part throttle economy without killing WOT performance. Provided high stall at idle to prevent creeping with drum brakes and the AC on; low stall at part throttle; and high stall at WOT.

Reliability of a multi-piece variable pitch stator is acceptable. But a 1 piece stator with no moving or electrical parts is obviously more reliable.

Nonetheless, it could be incorporated. All things considered, the biggest detriment would be consistency. Drag racers STOPPED using them for that reason. Perhaps a servo based VP stator could fix that, but....

Basically, no one cares about VP any more. For a pro-touring application, we use a looser than stock (but not loose) stall speed based on a CFD designed late model turbine/impeller core; a lock up clutch (for when torque multiplication has peaked); overdrive (too allow for a better gearing) and a computer to get the most of everything. First gear on both a 4L80E and TH400 is 2.48. But overdrive lets you run a lower final drive ratio. That concept is enough to render the VP stator obsolete.

I put my rocket scientist hat on and looked into VP stators for about seven minutes. Reliable or not, all of those little stator fin hinge pins seem contrary to the KISS principle.