Chevy Volt: The Engineering Challenges of Generator Mode

[AMERICA 123]

Given how the Prius was treated as a National State Secret between 1992 - DEC1997 and Toyota 's / Honda's general opaqueness on things like this and much, much, more, - this whole discussion about GM transparency by lower form Toyotites is more than a little humorous.

__________________________

Maybe we should have a poll and pick the best and worst trolls on the forum ?

[goblue]

Originally Posted by andretti

I never said transparent means revealing trade secrets! Read AND think before YOU post!!!!

That's what you have been arguing (unsuccessfully) for your last few posts...

Defending JOHN usually puts you in an untenable position. GM's transparency on the VOLT has been unprecedented when you realize this is an entirely new drivetrain. As AMERICA 123 points out - they have been far more forthright with information than Toyota was with the Gen I (or II) Prius.

[jtrav91]

What is the mpg what the engine is running?

[goblue]

Originally Posted by jtrav91

What is the mpg what the engine is running?

About 50, GM is still tweaking the programming to address NVH and perception issues with the generator. They could also adjust the performance of the electric motors to increase that number.

Better performance and better MPG in all circumstances over the Prius is a goal of the program.

[AMERICA 123]

Originally Posted by jtrav91

They did for the 2010.

They most certainly did not.

They improved the situation but its still there and is still quite noticeable.

The VOLT people describe it correctly in terms of the 2010.

Really good to know it sounds like they realise what a turn off that really is.

[Tone]

Regarding the Prius "shutter" -- I've driven the last Prius and the shutter is from when the electric motor starts the internal combustion engine (ICE).

I'm sure Toyota can work to minimize it -- it's already much smoother than starting a conventional motor with a starter -- but the need to get the ICE running as quickly as possible (say accelerating hard from a stop to make a left hand turn) mean that the best they can do is isolate it.

The Volt, OTOH, goes in with a huge advantage in this area: there is no need to get the ICE up an running quickly as it isn't connected to the wheels. So GM has lots more options to minimize and isolate the ICE start-up than Toyota has with HSD.

The good news is that, even in the old Prius, the shutter was hardly objectionable. Most people probably dislike the disconnection between engine noise and road speed that is part and parcel of the CVT than they do the shutter. That GM can hone in on that fine level of refinement bodes very well for were the Volt's development is at, methinks!

[jtrav91]

Sounds like the engineering challenge comes from making Volt engine run and stop predictable. Prius owners didn't find any shutter objectionable because they knew exactly when it would happen.

[Dr. Show-Me]

I drove and rode in my brother's Prius, about a 2006 model. There is a shudder when the ice comes on, but it is a minor issue.
To me, a bigger issue is the low performance of the car. There is marginal power to pass on a 2 lane highway.
Even though Al Gore Jr. got a ticket in a Prius doing 100 mph, I'll bet that it took a LONG TIME to get up to that speed.

[jbernie]

Originally Posted by jtrav91

Sounds like the engineering challenge comes from making Volt engine run and stop predictable. Prius owners didn't find any shutter objectionable because they knew exactly when it would happen.

That sounds like a bit of a cop out by Toyota, nothing against you, but the way you worded it makes it sound like
1) we know it will happen
2) we know why
3) we know when
4) because of 1-3 we will accept it as a part of the package

GM is leaning more towards
1) we know it can happen
2) we know why
3) we know when
4) because of 1-3 we will NOT accept it as a part of the package and are doing everything to prevent it.

Toyota is just selling it as part of the package of being eco friendly and skimping on the cost of making the package even better.

[jtrav91]

Engineering is a balance. You can improve handling of a car just by putting better tires on. But that isn't considered a skimp if you don't. Most people don't either.

[goblue]

Here's JOHN's latest attempt at trying to discredit the VOLT

http://priuschat.com/forums/chevrole...tml#post934494

EVIL GM strikes again....

>>>>>

I've driven the Gen II Prius, the shudder was a little annoying. I agree with others, what was far more annoying was the power and handling.

Something to remember, when a Toyota fan (like JOHN and others) drive a Toyota, those minor annoyances are viewed as compromises, they aren't mistakes - if Toyota couldn't do better - than it couldn't be done better - or there was a good reason.

When GM doesn't do it perfect, its because of a big union and crappy engineers.

I for one am glad GM is sweating the details like this. The all out assault is exactly what GM needs.

[Dr. Show-Me]

I guess I am curious why GM haters, Toyota lovers and other miscreants frequent a GM fan site. They seem to be emotionally driven to "hate" GM, which is, after all, simply a US car company that makes cars and trucks.
GM isn't some evil empire that seeks to destroy all on the way to world domination. GM is an old corporation dragged down by long-term legacy costs, 30+ years of mismanagement, high labor costs and too many retirees that continue to draw earned benefits. In accordance with US bankruptcy laws, they have done a chapter 11 re-organization, much as any failed enterprise can do.
John1701 is a version of the haters, from a Toyota standpoint, while MG is a self-appointed "expert" who incessantly denigrates GM and Cadillac in particular.
If you hate GM so much, move on, there's nothing here for you.......

[PA Dweller]

Originally Posted by Dr. Show-Me

I guess I am curious why GM haters, Toyota lovers and other miscreants frequent a GM fan site. They seem to be emotionally driven to "hate" GM, which is, after all, simply a US car company that makes cars and trucks.
GM isn't some evil empire that seeks to destroy all on the way to world domination. GM is an old corporation dragged down by long-term legacy costs, 30+ years of mismanagement, high labor costs and too many retirees that continue to draw earned benefits. In accordance with US bankruptcy laws, they have done a chapter 11 re-organization, much as any failed enterprise can do.
John1701 is a version of the haters, from a Toyota standpoint, while MG is a self-appointed "expert" who incessantly denigrates GM and Cadillac in particular.
If you hate GM so much, move on, there's nothing here for you.......

Seriously.

[fan]

Originally Posted by jtrav91

Sounds like the engineering challenge comes from making Volt engine run and stop predictable. Prius owners didn't find any shutter objectionable because they knew exactly when it would happen.

I also say this is a thing to consider. And the behaviour must be one specific to an electric car not one run by a gas engine. Having the engine start for 2 minutes while making a pass and revving up and down may not be the way.
The mileage of Volt is 95% result of the concept. electric car with a gas engine range extender.
The optimization of the gas engine behaviour will add up say a 5-10% mileage increase if gas engine is actually used but optimization will mean revving up and down, unexpected start and stops. This will have a bad influence on perception.
It must be better to have teh engine run at constant rpm all the time. an adittional high rpm mode for emergencies.
and maybe a fixed minimum period for keeping the engine started - like 5 min. and ofcourse multiple periods when required - but this is with a ? with pros and cos.

[fan]

And...a (funny) thing to consider. Many people will often forget to plug-in their electric car. I ofthen forget stuff.
It's not a must like locking the door that you do without hesitation. If you don't plug-in the car, it won't be the end of the world.
So, got to have a good and not annoying reminder for this.
(text messaging would be anoying, how do you know the driver got home?, flashing red lights and alarm noises would also be annoying)
Well, it's not the biggest problem, but it's an interesting problem.
Maybe a Volt gadget mini-car with a sad smiley if not recharged. Placed in the bedroom, mm or maybe livingroom.