Some technical NX info I have learned.
06-28-23, 12:15 AM
#47
Pit Crew
Thread Starter
Depending on engine rpm, MG1 may not have to spin 'backwards' at 120kph/75mph.
When MG1 spins 'forward' slower than the engine (down to 0 rpm) it is providing an overdrive gear ratio. IOW, MG1 doesn't have to spin 'backwards' to provide overdrive.
Perhaps a more intuitive way to look at it...
If MG1 and the engine are spinning at the same speed; then, the eCVT output will also be spinning at the same speed... so, 1:1 gear ratio. So, as soon as MG1 is slower than the engine you have overdrive.
I don't have time to check for sure; but, I think at that speed, MG1 would only spin 'backward' if the engine rpm were below something like 2100 rpm.
When MG1 spins 'forward' slower than the engine (down to 0 rpm) it is providing an overdrive gear ratio. IOW, MG1 doesn't have to spin 'backwards' to provide overdrive.
Perhaps a more intuitive way to look at it...
If MG1 and the engine are spinning at the same speed; then, the eCVT output will also be spinning at the same speed... so, 1:1 gear ratio. So, as soon as MG1 is slower than the engine you have overdrive.
I don't have time to check for sure; but, I think at that speed, MG1 would only spin 'backward' if the engine rpm were below something like 2100 rpm.
Last edited by CdO; 06-29-23 at 10:31 PM. Reason: more intuitive... +typo
06-28-23, 07:01 AM
#48
Racer
08-31-23, 11:58 PM
#49
Pit Crew
Thread Starter
Launch Mode ??? (450h+ and 350h?)
Surely I am not the first to discover this; but, I haven't seen anything about it anywhere, so...
Background:
While I was doing some testing, I was wondering how best to perform a quick launch from a stop. Normally, the engine will be off at a stop... not ideal for a launch. Then I thought, I could use charge mode so that the engine would be running... better; but, would that affect the battery output?
Finally I thought, why not try to push the accelerator with the brake applied?
The engine will rev to about 4000 rpm for something like 5-10 seconds... release the brake and off you go. (If you don't release the brake before the 5/10 seconds is up, the engine speed will come down but continue running.) FYI: you will almost certainly have wheel slip.
Interestingly, the engine will come on even in EV mode.
Background:
While I was doing some testing, I was wondering how best to perform a quick launch from a stop. Normally, the engine will be off at a stop... not ideal for a launch. Then I thought, I could use charge mode so that the engine would be running... better; but, would that affect the battery output?
Finally I thought, why not try to push the accelerator with the brake applied?
The engine will rev to about 4000 rpm for something like 5-10 seconds... release the brake and off you go. (If you don't release the brake before the 5/10 seconds is up, the engine speed will come down but continue running.) FYI: you will almost certainly have wheel slip.Interestingly, the engine will come on even in EV mode.
Last edited by CdO; 09-01-23 at 12:01 AM.
The following users liked this post:
clmk (09-01-23)
09-01-23, 12:30 PM
#50
Surely I am not the first to discover this; but, I haven't seen anything about it anywhere, so...
Background:
While I was doing some testing, I was wondering how best to perform a quick launch from a stop. Normally, the engine will be off at a stop... not ideal for a launch. Then I thought, I could use charge mode so that the engine would be running... better; but, would that affect the battery output?
Finally I thought, why not try to push the accelerator with the brake applied? The engine will rev to about 4000 rpm for something like 5-10 seconds... release the brake and off you go. (If you don't release the brake before the 5/10 seconds is up, the engine speed will come down but continue running.) FYI: you will almost certainly have wheel slip.
Interestingly, the engine will come on even in EV mode.
Background:
While I was doing some testing, I was wondering how best to perform a quick launch from a stop. Normally, the engine will be off at a stop... not ideal for a launch. Then I thought, I could use charge mode so that the engine would be running... better; but, would that affect the battery output?
Finally I thought, why not try to push the accelerator with the brake applied?
The engine will rev to about 4000 rpm for something like 5-10 seconds... release the brake and off you go. (If you don't release the brake before the 5/10 seconds is up, the engine speed will come down but continue running.) FYI: you will almost certainly have wheel slip.Interestingly, the engine will come on even in EV mode.
09-02-23, 12:59 AM
#51
Pit Crew
Thread Starter
Some further info... At max charge the battery pack voltage is ~391 V, at zero EV range it is ~335 V. For one of my 0-60+ tests, I started at 376 V; when the battery reached its max output the voltage had already sagged to 354 V; by the time I reached max EV speed the voltage was only 333; then, quickly recovered to 373 V afterward. This was a relatively high state of charge... 7 of the 8 bars. Maybe if the battery was cold or I started with 6 bars the engine would have come on?
Edit: If you let the car sit idle the engine will start when the battery reaches ~331 V. Maybe ~331 is the minimum allowable voltage no matter the temperature or SoC?
Last edited by CdO; 09-02-23 at 03:24 AM.
09-02-23, 06:37 PM
#52
On a long downhill descent, even with plenty of room left for regen charging, I've had the engine turn on part way down for it's own reasons.
I wonder if it was to aid in engine braking because I'd done too much regen or it was beyond the regen to hold the car to the cruise control speed.
I wonder if it was to aid in engine braking because I'd done too much regen or it was beyond the regen to hold the car to the cruise control speed.
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CdO (09-02-23)
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