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sThe torque is the torque at the motor not at the wheels, just look at the numbers
to get 115kW @ 400Nm => 115kW*9549/400Nm = 2700rpm
~2meter circumference of wheel * 2700/60 = 90m/s = 324km/h
when people talk about power/torque "at the wheels" is it is just ignoring the gearbox etc. efficiency
not for a ball park figure, it is simple physics, Newtons second law
-Lasse
Yeah, the original Honda hybrid is a MESS! Who would have thought you could get away with stacking 120 NiMH D-cells in series, with minimal cooling and no cell balancing system, and hit it with 100A charge/discharge cycles for years? I'm amazed the things don't explode the first time you pull onto the highway! (And, I own one of them...)
The original design would run fine without the hybrid system. They have a
12 V conventional geared starter and a bit too-small 12 V battery. So, it will start and run with the hybrid battery totally shot. (Using the 12 V battery all the time will croak the 12 V battery pretty quickly, though.)But, without the "integrated motor assist" system, the ICE is REALLY anemic! Also, it changes power output with a hydraulically-controlled intake cam timing system, that is fairly slow to move. So, it takes about a second or so to go from idle to full power, or back down. The hybrid system masks this lag (when it is working).
Jon
On Monday, December 14, 2015 at 11:25:15 AM UTC-8, bitrex wrote: ......
....
Probably most cars have > 1400 foot pounds of torque at the wheels when in first gear.
Bottom gear in a conventional car usually gives about 12 - 16 :1 torque multiplication (4 in the gearbox, 3-4 in the final drive). You only need 100-150ft-lbs of engine torque to give that much torque.
kevin
That's exactly what Toyota did with the first generation Prius?
kevin
Yes, it looks like whatever page I was looking at got it wrong. There is an approximately 2:1 gear reduction from the main electric motor to the wheels.
The power train of the Volt is interesting, the drive wheels are connected to a planet carrier which is driven by the 150 HP electric motor connected to the sun gear.
There is also a ring gear which is connected to a second motor which also functons as a generator. When the car is above 70 mph the main motor is not efficient enough, so the ring gear engages the planet gears and the second motor/generator also contributes.
When in "charge sustaining" mode (or battery depleted), the ring gear disengages and the second motor is used as a generator to power the main motor. When the car goes above 70 in this mode, the gas engine also engages directly with the drivetrain, along with running the generator to turn the primary motor.
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Three sentences above you said "My 1972 Corolla did 0-60 in a bit over
22 seconds" but now you are saying "My clocked 0-60 time in my Volt is just under 8 seconds"? Do you have a Volt or a Corolla? What are we comparing here?
Ive never owned a 1972 Corolla. I was still 8 years from being born...:(
I think that was someone else.
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Sorry. I thought I was responding to Lasse.
Instead of arguing all this stuff, everyone should go out and test drive a Volt. I recall it had some early teething problems, and there are still a few bugs and things I dont like, but in general the GM engineers knocked it out of the park on this car.
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Yes, but they had a liquid cooling system with a pump and radiator up front. They also had a cell balancing system that measured each cell's voltage and shifted charge around to keep weaker cells from getting drained too far. I think ALL versions of the Prius also used prismatic cells instead of cylindrical ones. The cooling plates convey heat much better from prismatic cells. But, the Prius can run off battery power for maybe up to one mile.
The Honda hybrid system is mostly for overcoming the VERY weak engine when accelerating from a stop. It is VASTLY smaller than the Prius electric drive train.
On the other hand, the Honda hybrid has the most advanced engine in any passenger car, period. It normally runs in a partial Atkinson cycle, where the intake/compression stroke is effectively shortened by leaving the intake valve open for part of the compression stroke, and thus making the power stroke effectively longer than the compression stroke. First, this gets rid of pumping loss, as there is no throttle to restrict air entering the engine. Second, by reducing effective engine displacement to regulate power output but always getting the full power stroke, it recovers more energy from the fuel. Like most hybrids, it also shuts off the engine when standing at a stoplight. Finally, they use a continuously variable transmission with a computer-controlled clutch, no torque converter. All of this makes it a lot more efficient than some other systems, and just works!
I have to admit, the Prius planetary gear/VFD electric transmission is QUITE ingenious! But, it requires two motor/generators and associated VFDs to just connect the motor and engine to the wheels. I suspect it has to be just a tiny bit less efficient than the Honda scheme. Also, if any of this electrical stuff pops, the car is immobilized. With the Honda, as long as there isn't a massive short in the VFD for the IMA motor, the car can be driven with the IMA system totally out of commision.
Jon
Two different people with two different cars. I owned the Corolla (which was actually 12 seconds 0-60).
Is this the original Insight you're talking about? The two-seater?
I talked with a guy at the gas station driving a 2001 model the other day - it had 190k miles on it with no major problems. So apparently in some cases it can be quite reliable.
Having an aluminum body in the New England winters probably helps longevity as well.
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The Prius batteries are air cooled not liquid cooled. There is an air inlet at the side of the rear seat, if you are not careful it can get blocked and battery overheating reduces system power. . ...
The first generation Prius used cylindrical D cells. The 2004 and later versions introduced prismatic cells.
Agreed - I am not keen on the Honda system.
...
I would dispute this. Toyota introduced the Atkinson cycle engine in the Prius in 1997. It is also now common in non-hybrid engines such as Mazda's Skyactiv system.
...
Kevin
On Monday, December 14, 2015 at 1:57:19 PM UTC-8, bitrex wrote: ....
The Tesla model S has a reduction ratio of about 10:1 from the motor to the wheels. So do most electric cars.
the Chevy Spark EV is unusual in that it only has a 3:1 ratio but a higher torque motor (~400 ft-lb in the 2014 version).
....
kevin
On Monday, December 14, 2015 at 5:00:14 PM UTC-8, Ralph Barone wrote: ...
That is being optimistic if the car was unmodified.
This link states 15 to 18 seconds depending upon model for cars of that era.
kevin
Okay, so it looking at another diagram it looks like there is also a 3.something reduction from the main motor to the sun gear, and then a 2.something reduction from the output of the planetary gears to the wheels....does that make more sense? None of the diagrams I'm finding are particular clear...I'll probably take a look at the patent
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The 1.2L KE engine was the 18 second car. The 1.6L 2T engine was good for about 12 seconds. I had a '74 Corollaskate SR5. It handled well, and, after a fashion, could build up a good head of steam on a flat track. But hill climbs were my thing. It just didn't have that zing. That annoyed me. So I fixed it. 2 Webers, a cam change and a couple of exhaust header experiments got me down into the 9.5 second range. That was OK - most sporty cars of that era were no faster.
-- Grizzly H.
All that sounds like complexity overkill. Oil hit $34.53 a barrel today, in celebration of the COP-21 agreements.
My Audi has a six-speed dual-clutch automatic transmission with no torque converter. It's very efficient and shifts in 50 milliseconds. That design, I think invented by Borg-Warner, is becoming more popular. Some mechanical genius needs to invent the mechanical equivalent of a buck-boost switching regulator.
And starting at practically zero RPM.
Could be. I sold the car in 1988, so memories may not be terribly accurate. The car was a 1972 chassis that I had spliced the engine and tranny from a
1975 SR5 into, so it might have been a hair lighter than your average 1975, or a shade more powerful than your average 1972. Or possibly the rear diff ratio changed between 1972 and 1975, so my speedometer calibration might have been out.ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.