ICE takes longer to turn on when starting car; good or bad?

Perhaps to rephrase what Britprius is saying, does this make it clearer: If you need to reverse first (out of a garage for example), it would be more efficient to wait until after reversing to force the engine on to hasten the S1 warm up.

 

I tried this today and my engine turned on while i was in reverse. This was done right after i started the car

 

The engine's very inefficient during stage 1. I argue that I'm better off getting it through that without loading it by starting it early. There's no coupling of the engine to the wheels while reversing.
As far as hastening the warmup is concerned, the sooner I start it the sooner it's warm.

 

If you look at the animation near the bottom of the page Toyota Prius - Power Split Device the outer "yellow" ring is driven directly by MG2 and this in turn is coupled to the wheels. If MG2 turns the wheels turn.
If the outer ring turns clockwise the car is driven forwards, and anticlockwise backwards. The only method of driving the outer ring anticlockwise is by reversing MG2. Moving the slider for MG2 will give you both forwards and reverse travel. The engine slider cannot do this as the planet gears "orange" always run in the same direction. Remember what you are looking at is the sum total "ignoring the differential" of the complete Prius transmission. There is no means of mechanically changing the direction of drive from the engine to the wheels as there is in all other manual or automatic transmissions, or disconnecting the engine mechanically from the transmission.
The engine can only run in one direction, and since it is permanently coupled to the planet gear carrier "orange" it can only do one of two things when it is running. (1) Try to drive the "yellow" ring clockwise if the sun gear "blue" has any load on it "that is generating electricity" in the proportions of 62% of the engines torque to "yellow" in the wrong direction and 28% to "blue" or. (2) If the sun gear "blue" is allowed to spin freely the engine through the planet gears "orange" will impart only very slight forward drive to "yellow" due to friction within the gears and MG1.

John (Britprius)

 

my gen II's always fired up as i was backing out of the garage, maybe 3 or 4 seconds?

 

So if the engine's idling at, say, 1275 RPM, MG1 will max out at about -5 mph.
Interesting.

I'm not convinced that what it shows is harmful to anything. The main scenario I'm trying to avoid is starting the car from cold in a parking lot near a 50 mph thoroughfare; the engine starts after I've backed out. If try to accelerate onto that road before I'm out of Stage 1 the car will respond sluggishly as it tries to do it all with MG2 then will rev up the engine if I request more power than that gives me.
Really ugly.
Of course the ultimate solution is to sit in the car for a minute with the engine warming up before going anywhere but that takes more discipline than I have.

 

At what state of charge was the HV battery when the engine started? I find if the battery is at 4 blue bars or lower the engine will start, but anything higher than this and it does not. As I said in post 7 it does depend on the state of charge of the battery. I also notice that if you are moving in reverse, and the engine starts you can feel the reduction in reverse power particularly if your reversing up a hill.

John (Britprius)

 

I think most of the time when I start the car, the battery is above 5 blue bars. I live on flat ground and my battery is usually pretty charged up when I stop at home.

What I've noticed before is when the car is slightly warmed (in the middle of the day), I'm able to reverse without the engine coming on for maybe 10 seconds (haven't really had to back up for more than that). When the engine is cold (in the mornings), the engine would fire up even if I go into reverse.