Quote:
Originally Posted by Cobb
I think the chevy hhr has a no lift shift on the manual models that allow clutchless shifting once you start off.  |
No. Certain turbocharged GM vehicles have what's called "No Lift Shift", which basically means they are designed to be powershifted. Powershifting is taking the car to redline at WOT, pushing in the clutch, selecting the next gear, and then letting out the clutch again, all while holding the throttle wide open.
This can be done in ANY vehicle with a manual transmission, but the GM system cuts engine power during the shift to minimise drivetrain shock when letting the clutch out while keeping the throttle open. This helps to keep the turbocharged engines "on boost" during the gear change. Closing the throttle on a turbocharged engine mid-shift causes the blow off valve to de-pressurize the intake tract and slow the turbocharger down, which takes some time to overcome once in the next gear.
This thread has gone severely OFF TOPIC. The OP was interested in intelligent feedback circuits to the motor controller in an EV that would allow the motor to synchronize its speed with the next gear to be selected.
The new Corvette Stingray has a rev-matching system that does something similar,
but forget about the fact that it has a gasoline engine and a clutch that still requires disengaging.
The specific technology I'm refering to here is the sensor system they developed for the shifter. It's a sensor that monitors the shift lever movement so the ECU knows which gear you are about to select, whether you are up or down shifting.
anderwgray, I believe this is what your idea would require... some sort of method to tell the controller which gear you are going into, and some smarts in the controller that would compare the desired gear to the current vehicle speed and match them up. THIS would make perfectly smooth clutchless shifting a reality with an EV.
It would also work with a gas engine as long as the RPM could be accurately controlled, BUT THAT'S NOT WHAT THIS THREAD IS ABOUT!
