brillo

I'm starting to read about several "non-hybrid cars" that are addopting some of the hybrid tricks for saving fuel such as regenerative breaking to assist the alternator and stoping the motor when the vehicle isn't moving, such as idling in traffic.

This is all great, I'm all for coming up with was to save energy, but I don't exactly understand how the start/stop could work without a true hybrid car.

They say the engine fires up as soon as you push the clutch in or step on the gas, but most cars take a couple of seconds to fire up, that seems like that would create a bit of a lag, and not be anywhere near as seamless as you would want.

Now hybrids use the electric motor to get going while the engine fires up, therefore you don't notice the engine start/stop.

Any ideas how they make this work without being annoying? would you need a super starter to pull this off? Does the starter get you moving basically?

MikeW

The GM system in the VUE uses a belt (not cogged I believe) so there is some sort of bi-directional tensioner so it doesn't slip when there is a load reversal.

When the brake pedal comes up and the switch (BOBO in GM parlance) is opened, the restart system goes to work. The starter/generator spins the engine from 0 rpm to idle (or a high idle speed, say 750rpm) simultaneously an auxiliary pump provides oil pressure to the transmission (normally the transmission's oil pump is spun when the torque converter is rotated-with the crank)
So now the engine is ready to go, and the transmission was already working on engaging first gear. All of this in <1 second, hopefully.

Honda had the start/stop in the insight. The IMA-integrated motor assist. It was a 'helper monkey' of a motor (Mojo) I think it was ~10 kilowatts peak, ~6hp as quoted at 5700rpm. That is enough power to move the car say under 10mph, but Honda did not configure it that way. You have to take the car out of gear, and when you release the clutch, the engine is stopped. So when you want to get going, it will spin the engine up to idle speed and then start the fuel.

Most starters will only spin an engine to say 250rpm (fully warmed up oil with full oil pressure and full battery voltage)
So a cold engine might only spin at 125-150rpm, and the engine has to 'catch' and rev above the minimum stable idle speed and then come down.

brillo

good info.

If it can be done right, more power to them. Hell they could integrate it for us too.

The starter motor might make more torque anyways