Chevrolet Considering 1.4L Turbocharged Engine for Volt

[ral1960]

Quote: If using a gasoline engine to power an electric motor were so efficient, the streets would be full of such vehicles. (Our guess: The car will be lucky to get 15 mpg under gasoline power.)

What an idiot. This would only make sense if the engine were recharging the battery at the same rate the electric motor used the power.

The algorithm for recharging will hopefully be flexible: why use a lot of gas for extensive recharging, if you're only going a few more miles than the battery can do alone?

[FBODYRULES]

this is rubbish, why would it even need a turbo? and also 50mpg...I really hope this figure is wrong!

[uujjj]

the chevy volt engine will only have to operate efficiently at a single RPM level. it seems to be the perfect opportunity for a low complexity HCCI engine, since the difficulty of HCCI is having it operate at all different points.

[kenman923]

A turbocharged engine in a Volt. That really makes sense. NOT!!!!!!!!

[blkwrxsti]

I think some of you are reading out of a rulebook recently ripped up by the Cobalt SS, the Tahoe Hybrid, and even the Saturn Sky. Remember that the Tahoe (and more recently the upcoming prius) use a larger engine to increase fuel economy, by making sure that the engine will be operating efficiently (not maxed out) during normal driving. Allow me to re-familiarize you with a torque curve for a turbo'ed DI engine:

http://media.gm.com/us/powertrain/en...obalt%20SS.pdf

As luck would have it - slow spinning, big throttle opening turbo engines can easily be tuned for maximum efficiency and minimum noise. Naturally aspirated engines would have to rev higher, make less torque, and still wouldn't be as efficient. Rich mixtures for turbos were only necessary to prevent transient lean conditions and knocking, but the DI and boost control can easily manage those when a computer is sending in predicted throttle openings for the next two minutes.

So let's just say that you are taking your brand new Chevy Volt from NY to LA. The engine's job on this trip is to supply enough juice to the battery to get it back to ~75% charge (around halfway), and then to provide enough electricity to keep the motor happy and the battery from cycling, while it uses an average of 12 horsepower.

In this situation, you'd want to have one max efficiency mode for the engine that puts out around 50 hp, so that the engine can do the hypermiling for you, but I think this behavior would put customers off. Having an engine come on every 5 minutes and make lots of noise would be very annoying for 2000 miles, and it's wearing out your precious new $20K battery pack.

I think GM is more likely to make the engine very efficient and smooth between 1000 and 4000 RPM, so that it can change pitch with speed or "gas pedal" so they can keep the battery from cycling and aging.

If the main use for this car is going to be electric only, my guess is that the range extender is not going to put any wear on the battery unless absolutely necessary (passing a semi or two during your trip).

[Randiglio]

Originally Posted by tholland

True... plus Atkinson would require a few different internals.

Not nessecarily true, I believe both the prius 1.5 and the TWO MODE 6.0 acheive an Atkinson cycle thru the use of late closing intake valves.

http://www.toyota.co.jp/en/tech/envi...Reports_12.pdf
See page 12 for prius

http://media.gm.com/us/gmc/en/produc...d/09index.html
Some info on the TWO MODE!
OK, so "technically" they both appear to use a "modified" Atkinson cycle.

[FBODYRULES]

Originally Posted by osv_alero

Something amazing to think about;

2010 1.4L 4-cyl Turbo from GM has 140hp
1985 5.0 V-8 Thunderbird has 140hp

and a 1984 v6 firebird s/e had only 10hp less than the 1983 v8 trans-am,
v8's didnt get powerful again until 87

[Bvonscott]

BREAKING NEWS! GUESS WHAT I FOUND!

PLEASE GO HERE TO SEE A PIC OF THE VOLT RANGE EXTENDING ENGINE DURING TESTING:

http://media.gm.com/wieck/home/site/index.html

click most recent catagory
go to page 2
picture 7 is 4CYL range extender pic
picture 8 is a pic of several computer screens and "1.4L four-cylinder engine and electric motor "
HMMMM.

The 1.4 range extender is not turbo
It has a transmission attached, maybe for testing purposes I dont know.
The picture of the screens looks to be showing a wireframe production volt. Notice the "green" highlights.
Anyone know what all that coded stuff means on the screens?
HMMMMMMMMMM.......

[ronald mcretard]

Originally Posted by Bvonscott

BREAKING NEWS! GUESS WHAT I FOUND!

PLEASE GO HERE TO SEE A PIC OF THE VOLT RANGE EXTENDING ENGINE DURING TESTING:

http://media.gm.com/wieck/home/site/index.html

click most recent catagory
go to page 2
picture 7 is 4CYL range extender pic
picture 8 is a pic of several computer screens and "1.4L four-cylinder engine and electric motor "
HMMMM.

The 1.4 range extender is not turbo
It has a transmission attached, maybe for testing purposes I dont know.
The picture of the screens looks to be showing a wireframe production volt. Notice the "green" highlights.
Anyone know what all that coded stuff means on the screens?
HMMMMMMMMMM.......

Good find - is that the actual production Volt? Looks a lot different than the concept.

[Jimmy Jive]

[zete]

Originally Posted by kenman923

A turbocharged engine in a Volt. That really makes sense. NOT!!!!!!!!

Sure it makes sense. It's a "go fast" feature. You can have the regular Volt or the Turbo Charged one! Ooooh. Turbo.... Just picture it with the Turbo badge on the back! It'd surely intimidate all those Prius owners

I can see GM using the 1.4l but as most of us can determine, turbo-charging the generator is silly.

Plus, I do wish some folks would realize that generators run efficiently at a constant speed. I think some don't get the difference between an engine that powers a car and a generator that generates electricity. They're not the same. And it's why a turbo on a generator makes little sense since there's no variability in power required.

But I'm probably spouting to the wind. Sigh.

[s10baja]

I see power to the rear wheels...
HMMMM.... ( :

[Smaart Aas Saabr]

Originally Posted by zete

Sure it makes sense. It's a "go fast" feature. You can have the regular Volt or the Turbo Charged one! Ooooh. Turbo.... Just picture it with the Turbo badge on the back! It'd surely intimidate all those Prius owners

I can see GM using the 1.4l but as most of us can determine, turbo-charging the generator is silly.

Plus, I do wish some folks would realize that generators run efficiently at a constant speed. I think some don't get the difference between an engine that powers a car and a generator that generates electricity. They're not the same. And it's why a turbo on a generator makes little sense since there's no variability in power required.

But I'm probably spouting to the wind. Sigh.

Of course a turbocharger is useful on a generator. With this you can make a higher power generator on a lower displacement.

I ACTUALLY HAVE a generator that is turbocharged. 30 kWe output, it is a 4-cylinder turbocharged diesel, all made in China

For the Volt there is significant variability since the generator has to power the car firstly (so about 30 kWe) and then also charge batteries... at a low speed the power consumption of the motors is less but the batteries can only be charged so quickly.

[WishIhadatruck]

Some generators use a computer controlled invertor to generate the correct frequency of AC power so they can run at slower quieter speeds for low power needs then if more electrical demand is required (acceleration after the batteries are drained) it can increase rpms and make more power as needed. That is the most fuel efficient when supplying household current. The smallest Honda generators that you can carry around like a suitcase have a reputation for being very quiet partly because they often run at slower rpms. Some scenarios make a turbo pratical but most of us (incuding myself) have no idea exactly how the GM engineers have designed it to work. Based on some of their info. it appears once the batteries are drained you rely on mostly generator power to move the car so a variable rpm generator would make sense and a turbo might make sense then as well if you need even more power. As someone already said you can only charge the batteries so fast so running almost directly off the generator makes some sense once the batteries are drained. We'll have to wait to see the details.