Quote:
Originally Posted by Audiofn
1) When traveling down the road at about 70mph the tach can be any place from 2000 RPM going down a hill and then 4,000 RPM going up a hill/incline. Do these transmisions not "lock up" like a normal tranny?
|
The drive train has a continuously-variable transmission in it (CVT). The computer controls the RPM of the engine via the setting of the CVT and the throttle and attempts to optimize the torque output for the load demand. The load is either the drive shaft, which can drive the wheels and the torque electric motor, and independently from that the Motor-Generator. By regulating the current flow, both electric motors may be a load (charging the battery) or a negative load (driving the drive train).
Complicated? Yep. I haven't been able to find any source for exactly how the system tries to optimize, but you can derive much of it if you know about optimal torque/RPM settings of the Atkinson-cycle ICE. I think it is a trade secret to Ford.
I have observed that the algorithm is fairly stable -- on my FEH I don't get varying RPMs unless I change the setting of the accelerator pedal or the terrain changes. If you are seeing that there might be something wrong.
Quote:
Originally Posted by Audiofn
2) can some one explain to me the difference between D and L? I shift mine and it does not seem to really make much of a difference.
|
It was a surprise to me that the difference between D and L is just a signal input to the computer, but that's what it is. You will get no difference on accel, but when your foot is off the accel pedal the L signal will slow the car faster in regenerative braking mode.