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What to expect from the next model year Prius

311 messages,  Last post on Apr 26, 2009 at 5:43 AM

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What is this discussion about? Toyota Prius, Hybrid Cars, Car Buying, Hatchback, Sedan


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#102 of 311
Re: Forced Induction on the Prius [toyolla2] by wwest
Oct 24, 2007 (9:54 am)
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Replying to: toyolla2 (Oct 23, 2007 8:39 pm)

I'm glad to see that someone understands the e-CVT even better, moreso, than I do. But wouldn't changing the e-CVT's planetary gearset ratio allow for MG1 to remain in "control" of a higher HP ICE?
 
Not that such a thing is really in the realm of feasibility....
#103 of 311
Re: Waiting for the 2009 Prius? [dramades] by sailorman4
Oct 26, 2007 (6:24 pm)
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Replying to: dramades (Jul 17, 2006 2:20 pm)

Dramades: By 2009, gasoline will be $5.00 per gallon if this admistration keeps threatening to bomb more countries.
I went to the trouble of flying to Virginia from Florida to buy my Silver car with package #6 a week ago. Very glad I did. Think of how much you would save in gas costs, insurance and repairs versus waiting for the 2009 Prius.
I say buy now while they're available. Evro in Tampa.
#104 of 311
HSD Power Upgrade by toyolla2
Oct 28, 2007 (7:31 am)
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wwest I understand you're suggesting we increase the HSD ratio to avoid having the more powerful ICE overwhelm MG1 ?
The general HSD eqn of MG1 = ICE x 3.6 - MG2 x 2.6 ------- eqn #1
is to become, let's say, MG1 = ICE x 4.6 - MG2 x 3.6 ------- eqn #2 for the higher torque ICE.
 
At the present ICE rpm and MG2 rpm are 3644rpm and 1200rpm respectively passing through 20mph while accelerating.
 
If we wish to keep the ICE at 3644rpm, since lowering it would be defeatist, then substituting into Eqn #2 MG1 will have to move up from its current max of 10,000rpm to 12,442rpm.
An almost 25% rise that we know from Hybrid Camry is possible. It will have the effect of raising MG1 electrical output from 42.2Hp to 52.5Hp. The copper loss at 100 amp would remain unchanged. There will however be an increase in the iron loss at the higher excitation frequency but this may have marginal effect since these revs are only maintained during full acceleration ramps that last a few seconds.The voltage on the system will also rise thus impacting the semiconductor specifications for the inverter.
MG2 will be required to handle 52.5 +28 Hp or 80.5Hp instead of 67Hp and the machine loading above 51mph remains quite high because of the battery assist.
 
It's a long answer. As you would expect the gear ratios must be chosen to keep the rotating components within reasonable spin rates. As a result any increases in power input would be more propitiously handled by increasing the torque capacity of all the components involved.
One of the problems with HSD is the ring gear and the components connected to it. Rotating this assembly beyond 6000rpm raises a serious balance issue. It represents the output shaft of the whole system and this rpm at 100mph is fine for a planetary connected to a 4 cyl engine, later on however it may turn out to be too slow for the higher speed small engines in the pipeline. Secondly MG2 needs to be turning much faster at this speed. A 16,000rpm limit at 100mph would more than double the existing power density of MG2 if it was allowed its own 10:1 reducer at the wheel axle.
T2
#105 of 311
Re: HSD Power Upgrade [toyolla2] by wwest
Oct 30, 2007 (11:56 am)
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Replying to: toyolla2 (Oct 28, 2007 7:31 am)

" A 16,000rpm limit at 100mph...."
 
And just who would object if the Prius' top speed were limited to ~80 MPH..??
 
Will the current model even do 100 mph except downhill?
#106 of 311
Re: HSD Power Upgrade [wwest] by larsb
Oct 30, 2007 (2:54 pm)
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Replying to: wwest (Oct 30, 2007 11:56 am)

wwest says, "Will the current model even do 100 mph except downhill?
 
Yessir...........
 
By Gary Richards
Mercury News
Article Launched: 08/21/2007 01:39:13 AM PDT
 
All right Al Gore III, you're still the tops when it comes to speeding in a Prius - but not by much. Steve Wozniak is right behind you.
 
And when I say speeding, man o' man, do I mean speeding.
 
You probably remember when the son of the former vice president was caught going 105 mph in Southern California last month. Well, a mention of that in a recent Roadshow column led a buddy of Wozniak's to check in, claiming that the co-founder of Apple Computer was ticketed for going 105 mph on Interstate 5 earlier this year.
 
Whoa. Mr. Roadshow knows a good story when it plops into his lap. If true.
 
"Not true," Wozniak replied: "104 mph."
 
OK, squash that image of the Prius being wimpy, as Gov. Arnold Schwarzenegger had quipped this year. First, 105 mph, and then 104!
 
"I pleaded guilty, with an explanation," Wozniak said in one of several e-mails exchanged the past few days. "I said that I was really scientific, and in the last year had been in Athens, Moscow, Berlin, Frankfurt, Munich (twice), Zurich, Canada (three times), Columbia, Singapore, Japan, London, etc., and had gotten used to kilometer speeds."
 
The judge smiled. But he didn't buy it. The fine was about $700.
 
Wozniak was headed to Las Vegas for a business trip with his pal Dan Sokol on March 28. Little head wind, light traffic, a straight road. His Prius was sailing along so smoothly that neither realized the speed Wozniak was reaching.

 
Woz and Gore Jr. both clocked over 100
#107 of 311
Fast Company by toyolla2
Oct 31, 2007 (6:57 pm)
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Landspeed Prius Hits 130.794 mph at Bonneville
On 23rd December 2004 a modified Toyota Prius reached 130.794 mph on the three-mile short course at the Bonneville Salt Flats.
An engineering group from Toyota and Toyota Motorsports worked on the Prius for more than two months to prepare the vehicle.
The Landspeed Prius ran a stock Hybrid Synergy Drive powertrain. The transmission final drive gear ratio for the gas engine was modified from the stock 4.113:1 to 3.2, while the inverter voltage was increased to 550 from 500 volts. The engine redline was also changed for optimum performance.
A transmission cooling system was added to the front passenger area to decrease the temperature of the inverter and electric motors. Regular ice was constantly added to the system to prevent overheating. Ambient temperature on the salt flats was nearly 100 degrees with nearly 100 degrees humidity.

Thanks to greencarscongress for the above, although this probably showed here on Edmunds News and Views at the time, it was likely archived somewhere.
 
That aside, I have read that under ideal conditions Prius will cruise at 100mph with 49Hp so it would not be too severely taxed since the 1NZ-FXE engine produces 76Hp 5000rpm. As most know by now this engine has an almost flat torque curve with respect to speed, so this would correlate to an engine speed somewhere north of 3330 rpm. Bottom line At 100 mph Prius could cruise all day.
On the otherhand, I would not object to an 80mph Prius, unfortunately the tradeoff of adding something to the bottom end would not be that great since we are dealing with the HSD which is mostly a constant power system.
  
I should mention that here in the great white north they just added a new law. Go more than 30mph above posted limit and they impound the car, suspend your licence and impose fines between $2000-$10,000. The ink for this new law hardly dry but they've already caught (actually "surprised" would be a more accurate verb here !) over one thousand drivers.
T2
#108 of 311
Re: Fast Company [toyolla2] by wwest
Nov 01, 2007 (9:24 am)
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Replying to: toyolla2 (Oct 31, 2007 6:57 pm)

"unfortunately..."
 
The bottom end torque could be limited just as easily as top speed, not that TC wouldn't already, but only after the "fact". Perhaps a "snow" mode..??
#109 of 311
Re: Fast Company [toyolla2] by wwest
Nov 01, 2007 (9:27 am)
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Replying to: toyolla2 (Oct 31, 2007 6:57 pm)

"..Bonneville.."
 
I hope, like to think, they added some downforce "effects" and wider tread tires for that high speed run.
#111 of 311
Re: Rumours [hybridlover1] by stevegold
Nov 09, 2007 (5:35 am)
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That's 90 miles per Imperial gallon, somewhat better than 2004-2008. The batteries will remain Lead/Acid not Li-on as originally planned.

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