GM moves closer to HCCI engine production - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Scotsman · 05-06-2008, 05:06 PM

Imagine getting V6 fuel economy from your V8 Camaro. It could happen sooner than later with HCCI engine technology

Quote:

Previously we reported on a new technology dubbed homogeneous charge compression ignition, or HCCI, which allows petrol cars to improve fuel efficiency by as much as 15% by achieving combustion with only compression of the air-fuel mix rather than using a spark plug. The technology was pioneered almost 30 years ago but has only recently been subject to a great deal of interest from the auto industry, most notably from Mercedes-Benz and GM.

GM’s commitment to HCCI technology is especially strong, with the General implementing the technology into prototypes, including the Saturn Aura (pictured). In a new breakthrough, GM has announced it has engineered the technology to operate while a car is idling (previously it could only operate while a car was in motion), increasing fuel savings even further.

The HCCI system can now be used while idling and up to speeds of 55mph, but at speeds greater than this or when more vigorous acceleration is required, a traditional spark-plug system will be used. This means that HCCI equipped cars will have both technologies under the hood.

If combined with other fuel-saving technologies such as low-resistance tires and hybrid systems, the savings from HCCI could add up to be very significant.

While GM has been eager to develop the technology, other companies have adopted a ‘wait and see’ attitude towards HCCI, including BMW who is researching alternative methods to reduce the dependence on oil such as its hydrogen program.

Quote:

How HCCI works

HCCI, along with other enabling advanced technologies, approaches the engine efficiency benefit of a diesel, but without the need for expensive lean NOx after-treatment systems. Its efficiency comes from reduced pumping losses, burning fuel faster at lower temperatures and reducing the heat energy lost during the combustion process. Consequently, less carbon dioxide is released because the vehicle’s operation in HCCI mode is more efficient.

Highlights of the technology include:

- Engine efficiency approaching the benefit of a diesel with substantially reduced after-treatment cost
- Builds off proven gasoline direct-injection and variable valve actuation technologies
- Adaptable to conventional gasoline engine architectures
- Requires only conventional automotive exhaust after-treatment
- Compatible with all commercially available gasoline and E85 ethanol fuels.

An HCCI engine ignites a mixture of fuel and air by compressing it in the cylinder. Unlike a spark ignition gas engine or diesel engine, HCCI produces a low-temperature, flameless release of energy throughout the entire combustion chamber. All of the fuel in the chamber is burned simultaneously. This produces power similar to today’s conventional gas engines, but uses less fuel to do it.

Heat is a necessary enabler for the HCCI process, so a traditional spark ignition is used when the engine is started cold to generate heat within the cylinders and quickly heat up the exhaust catalyst and enable HCCI operation. During HCCI mode, the mixture’s dilution is comparatively lean, meaning there is a larger percentage of air in the mixture. This reduces the throttle losses of a conventional spark-ignited engine at low loads, helping the HCCI engine approach the efficiency of a diesel, but requiring only a conventional automotive exhaust after-treatment. Diesel engines require more elaborate and more expensive after-treatment to reduce emissions.

HCCI builds on the integration of other advanced engine technologies - some of which are already in production and can be adapted to existing gas engines. The cylinder compression ratio is similar to a conventional direct-injected gas engine and is compatible with all commercially available gasoline and E85 fuels.

“I am pleased with our engineering team’s progress,” said Stephens. “It is another initiative in GM’s advanced propulsion technology strategy to lessen our dependence on oil. HCCI, direct injection, variable valve timing and lift, and Active Fuel Management all help improve the fuel economy and performance of our internal combustion engines. I am confident that HCCI will have a place within our portfolio of future fuel-saving technologies.”

Achieving HCCI operation at idle has long been a challenge for HCCI engineers, because the relatively low-temperature and light engine load characteristics generally inhibit the proper thermodynamic conditions for successful, controllable autoignition. Also, heat is needed at start-up and idle to light-off the catalytic converter.

GM’s engineers overcame these challenges with advanced control of the direct injection system and a HCCI-specific cylinder pressure sensor system. After spark ignition is used to start the engine, the engine’s sophisticated control system manipulates the combustion process via input from the cylinder pressure sensors so that auto-ignition can occur during idle.

“Fuel consumption with a spark ignition engine is relatively high when idling, so this new development in our HCCI process helps to enhance fuel efficiency,” said Dr. Matthias Alt, HCCI program manager, GM Powertrain.

The emerging HCCI technology offers several paths for implementation in a production vehicle. GM’s strategy combines the efficiency enhancements of HCCI and the power-on-demand attributes of spark ignition. This combination delivers enhanced fuel savings over a comparable, non-HCCI engine, but with the performance consumers have come to expect during higher engine load situations, such as passing or entering a freeway.

“GM’s HCCI development focuses the technology where it will deliver the most benefit at the most reasonable cost for the consumer,” said Alt. “An HCCI engine that uses HCCI in the entire operating mode would be heavier, noisier, more costly and would not deliver the performance experience people expect from a modern car.”

With GM’s technology, proven gasoline engine technology is retained and the engine has spark plugs and a conventional ignition system. The vehicle operates in HCCI mode up to about 55 mph (88 km/h) and switches to spark-ignition for higher-speed, higher-load conditions. It also engages spark ignition mode for passing at lower speeds and other higher-load demands.

The Aura concept is powered by a 2.2-liter Ecotec engine that makes 180 horsepower (134 kW) and 170 lb.-ft of torque (230 Nm). It features a central direct-injection system, with variable valve lift on both the intake and exhaust sides, dual electric camshaft phasers and individual cylinder pressure transducers to control the combustion as well as deliver a smooth transition between combustion modes.

A sophisticated controller, using cylinder pressure sensors and GM-developed control algorithms, manages the HCCI combustion process, as well as the transition between HCCI combustion and conventional spark-ignition combustion.

Challenges for production

The biggest challenge of HCCI is controlling the combustion process. With spark ignition, the timing of the combustion can be easily adjusted by the powertrain control module, with control of the spark event. That is not possible with HCCI’s flameless combustion.

The mixture composition and temperature must be changed in a complex and timely manner to achieve comparable performance of spark-ignition engines in the wide range of operating conditions. That includes extreme temperatures - both hot and cold - as well as the thin-air effect of high-altitude driving.

Advancements such as idle operation and improved noise, vibration and harshness bring HCCI technology one step closer to production. GM’s global HCCI team will continue to refine the technology in the wide range of driving conditions experienced around the globe.

“Our development costs for HCCI are very expensive; however, we have made tremendous strides in bringing this much awaited combustion technology out of the lab and onto the test track with the Saturn Aura concept vehicle,” said Prof. Dr. Uwe Grebe, executive director for GM Powertrain Advanced Engineering. “More research and testing are required to ensure the technology is ready for the great variety of driving conditions that customers experience.”

http://www.motorauthority.com/news/t...ci-technology/

ToneyTone · 05-06-2008, 05:18 PM

Hmmm Interesting

*radz28* · 05-06-2008, 05:38 PM

+2; very interesting. You know the bug-eaters are having their way when a gas engine runs like a diesel. J/K

*DGthe3* · 05-06-2008, 11:16 PM

I wonder how much gas would this system save?

*Mindz* · 05-06-2008, 11:20 PM

Sounds like diesel technology. Heat up the cylinder and then use compression to combust the fuel. It's a diesel engine that uses gasoline, right?

Sterling · 05-06-2008, 11:34 PM

I think the 305 in my 3rd Gen had this technology. Every time I let someone else drive it, when I got it back it would run after I shut the engine off. That was working at idle for about a minute anyway... if I kept giving it gas I bet it would have done it longer.

*Mr. Wyndham* · 05-06-2008, 11:36 PM

Quote:

Originally Posted by DGthe3

I wonder how much gas would this system save?

"or HCCI, which allows petrol cars to improve fuel efficiency by as much as 15%"

The current, non-HCCI, 2.2 in the Cobalt XFE gets 25city/36hwy...so 15 percent increase: 28/40? Plus the DI and the VVT they've included in the Aura's test engine,...I'd say we're looking at an easy 45mpg four-banger.

Eat that, Prius!!!

Scotsman · 05-07-2008, 12:15 AM

Quote:

Originally Posted by Dragoneye

[I]

Eat that, Prius!!!

Amen to that!

*radz28* · 05-07-2008, 09:54 AM

Quote:

Originally Posted by sterlingnotes

I think the 305 in my 3rd Gen had this technology. Every time I let someone else drive it, when I got it back it would run after I shut the engine off. That was working at idle for about a minute anyway... if I kept giving it gas I bet it would have done it longer.

LOL; dieseling for the win!!! See, and no one like the LB9s (is that right?...) and L98s back in the day.

*The_Blur* · 05-07-2008, 10:27 AM

I'd love to see this happen. It's technology like this that makes me think GM will overcome new regulations on efficiency. Plus, more efficiency is always good.

GothamCamaro · 05-07-2008, 12:53 PM

Interesting, well that puts it back in my mind when it was mentioned early on that the Camaro could have 30 MPG, this sorta development now makes me think maybe it wasn't the 4 cyc that was only suppose to do that kinda mileage. Hmmmm..

Wow if this is in the new Camaro. I'm just losing my mind, is it April 2009 yet?!?!?!?!

MerF · 05-07-2008, 01:47 PM

Hmm.

There's something I still haven't been able to fathom yet. My '91 vert I had (305 TPI) got 21+ MPG on the highway, and this was 17 years ago in a CONVERTIBLE. My 400+ HP Supra got 25 MPG hwy, and it was a '94. early 90's HOndas could easily get 40 MPG on the highway...so why are these numbers so hard to believe now? I know cars are heavier now (duh, make them lighter and save gas folks!) but there's got to be something else wrong with the picture here that it's so difficult to fathom a V8 making over 25 MPG.

stovt001 · 05-07-2008, 01:49 PM

It mentions the added benefit of not using expensive diesel emissions systems. It also so should mention the benefit of diesel efficiency without diesel prices.

I'd pay a little extra to get this system in my Camaro.

Good53X · 05-13-2008, 11:49 AM

Actually, the large arguement for HCCI is the improvement in emissions.

Normally combusted gasoline burns, producing HEAT andthus NOx emissions. HCCI doesn't burn the charge, but actually harnesses the compression energy to combust the entire charge simultaneously. Because it doesn't technically *burn* (like in a diesel) there is actually very little heat produced.

They already have these engines running, but only for certain drive cycles. They are working on a way to get them to run under more conditions.

Essentially, using computer controlled forced induction and constantly monitoring cylinder temperature, intake charge temperature, and barometric pressure they can calculate how much intake duration (valve control) they need to get the engine to 'knock' at the right time.

Differenced between this and diesel... Much lighter block, less torque (no sustained burn). Ignition timing isn't adjustable by adjusting fuel, it's all computer controlled.

I don't know if that made any sense, but when I learned about this technology in class I geeked out. I'd be more excited in looking at what kind of POWER you can get out of your V8 than what kind of fuel economy you can get. HCCI engines produce vastly more power than standard combustion because of the energy that isn't lost as heat. However the engine sounds a little different :S

3whiterag · 05-16-2008, 10:28 AM

That is very intersting stuff! IMO hybrid technology is not the way to go. Emissons are lower but the impact on the environment in the long term is much more damaging with all the used up battery cells laying around. I think they are only good for 5 years use? and very expensive to replace. I would like to see hydrogen powered vehicles but I am not sure about the consequences of that either.
I was reading Cottage Life magazine the other day and there was a letter to the editor from a guy that drives a prius and he was extolling the virtues of it. Very ill informed and an unknown victim of mass advertising!

*TAG UR IT* · 05-16-2008, 12:02 PM

Dude.....I'll take 15% better fuel efficiency any day. Add that to VVT and AFM and we've got a winner!!!!!!!!!!!!

shadowed_Stranger · 05-16-2008, 06:16 PM

Quote:

Originally Posted by 3whiterag

Very ill informed and an unknown victim of mass advertising!

Hey, if Al Gore invented the internet, why would he lie to us about the prius and global warming?

05-06-2008, 05:38 PM	#3
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crapramento, Crapifornia Posts: 12,949 View My Garage	+2; very interesting. You know the bug-eaters are having their way when a gas engine runs like a diesel. J/K __________________ "...What IS true: We anticipated that this would happen - we are never finished - and yes, Ford DOES deserve to win now and then. To think that GM can come out with a car to make ford throw in the towel is simply foolhardy..." - fbodfather

05-06-2008, 11:16 PM	#4
DGthe3 Moderator.ca Drives: 05 Grand Am GT Join Date: Jul 2007 Location: Niagara, Canada Posts: 20,723	I wonder how much gas would this system save? __________________ Note, if I've gotten any facts wrong in the above, just ignore any points I made with them __________________ Quote: In 2014 the camaro will have ... a twin turbo v6 ... around 350 to 360HP No. Let me repeat that. No. FbodFather __________________ Camaro5 Fest III Information Camaro5 Fest III pre-registration

05-06-2008, 11:20 PM	#5
Mindz E.B.A.H. Drives: you wild... Join Date: Mar 2007 Location: In the happy padded room wearing a jacket that makes me hug myself... Posts: 16,512	Sounds like diesel technology. Heat up the cylinder and then use compression to combust the fuel. It's a diesel engine that uses gasoline, right? __________________ "J, you're my favorite Pokemod" ~Revo1

05-07-2008, 10:27 AM	#10
The_Blur Moderator, USN Drives: 2000 Firebird Formula NHRA SE Join Date: Nov 2007 Location: Officer Candidate School Posts: 12,712	I'd love to see this happen. It's technology like this that makes me think GM will overcome new regulations on efficiency. Plus, more efficiency is always good. __________________ Get a good deal on your purchase. Read this. 117:123 RESPECT ALL CARS. LOVE YOUR OWN. newborn gifts

05-07-2008, 12:53 PM	#11
GothamCamaro Then you're gonna love me Drives: 2010 Black Camaro Tumbler RS Join Date: Dec 2007 Location: NW Gotham, IL Posts: 1,599	Interesting, well that puts it back in my mind when it was mentioned early on that the Camaro could have 30 MPG, this sorta development now makes me think maybe it wasn't the 4 cyc that was only suppose to do that kinda mileage. Hmmmm.. Wow if this is in the new Camaro. I'm just losing my mind, is it April 2009 yet?!?!?!?! __________________ *Own- "Does it come in Black?" Exterior/ Grey Interior 2LT/RS Automatic* _____________________________________ The Batman would only drive a 2010 Camaro and buy from Camaro Scotty. 'Nuff said. *Anyone that knows of a place that is making the Concept Shifter for the new Camaro. (Auto specifically) Please let me know.* Order# NDTMVP Ordered 10/23/08. 2000 on 5/21/09... It begins..... 4B00 on 6/26/09... In transit to the Cave 5000 on 7/6/09 it waits for my arrival! 1000000 on 7/10/09 The Tumbler is in the Cave!

05-06-2008, 05:18 PM	#2
ToneyTone Drives: 07' Sunburst Cobalt SS/SC Join Date: May 2008 Location: Dallas, Tx Posts: 83	Hmmm Interesting

05-06-2008, 11:34 PM	#6
Sterling Drives: 2010 Camaro 1LT/RS M6 Join Date: Nov 2007 Location: Fairhaven, MA Posts: 5,910 View My Garage	I think the 305 in my 3rd Gen had this technology. Every time I let someone else drive it, when I got it back it would run after I shut the engine off. That was working at idle for about a minute anyway... if I kept giving it gas I bet it would have done it longer.

05-07-2008, 01:47 PM	#12
MerF Go Rays! Drives: 03 Trailblazer Join Date: May 2007 Location: St Pete, Florida Posts: 2,537	Hmm. There's something I still haven't been able to fathom yet. My '91 vert I had (305 TPI) got 21+ MPG on the highway, and this was 17 years ago in a CONVERTIBLE. My 400+ HP Supra got 25 MPG hwy, and it was a '94. early 90's HOndas could easily get 40 MPG on the highway...so why are these numbers so hard to believe now? I know cars are heavier now (duh, make them lighter and save gas folks!) but there's got to be something else wrong with the picture here that it's so difficult to fathom a V8 making over 25 MPG.

05-07-2008, 01:49 PM	#13
stovt001 Drives: 2006 Cobalt, 2004 Taurus wagon Join Date: Oct 2007 Location: California Posts: 3,817	It mentions the added benefit of not using expensive diesel emissions systems. It also so should mention the benefit of diesel efficiency without diesel prices. I'd pay a little extra to get this system in my Camaro.

05-13-2008, 11:49 AM	#14
Good53X Drives: 1988Nissan Pulsar (meh,beater) Join Date: Nov 2007 Location: Vancouver, BC, Canada Posts: 83	Actually, the large arguement for HCCI is the improvement in emissions. Normally combusted gasoline burns, producing HEAT andthus NOx emissions. HCCI doesn't burn the charge, but actually harnesses the compression energy to combust the entire charge simultaneously. Because it doesn't technically burn (like in a diesel) there is actually very little heat produced. They already have these engines running, but only for certain drive cycles. They are working on a way to get them to run under more conditions. Essentially, using computer controlled forced induction and constantly monitoring cylinder temperature, intake charge temperature, and barometric pressure they can calculate how much intake duration (valve control) they need to get the engine to 'knock' at the right time. Differenced between this and diesel... Much lighter block, less torque (no sustained burn). Ignition timing isn't adjustable by adjusting fuel, it's all computer controlled. I don't know if that made any sense, but when I learned about this technology in class I geeked out. I'd be more excited in looking at what kind of POWER you can get out of your V8 than what kind of fuel economy you can get. HCCI engines produce vastly more power than standard combustion because of the energy that isn't lost as heat. However the engine sounds a little different :S

05-16-2008, 10:28 AM	#15
3whiterag GM Powertrain Retired Drives: 67SS350, 87 IROC L98, 96SS ver Join Date: Jan 2007 Location: Niagara, Canada Posts: 349	That is very intersting stuff! IMO hybrid technology is not the way to go. Emissons are lower but the impact on the environment in the long term is much more damaging with all the used up battery cells laying around. I think they are only good for 5 years use? and very expensive to replace. I would like to see hydrogen powered vehicles but I am not sure about the consequences of that either. I was reading Cottage Life magazine the other day and there was a letter to the editor from a guy that drives a prius and he was extolling the virtues of it. Very ill informed and an unknown victim of mass advertising! __________________ http://i17.photobucket.com/albums/b7...g/100_1224.jpg http://i17.photobucket.com/albums/b7...g/100_1227.jpg http://i17.photobucket.com/albums/b7...g/100_1230.jpg I say nothing and by saying nothing or not, not saying anything does not imply that what you say is true or not true.

05-16-2008, 12:02 PM	#16
TAG UR IT www.Camaro5store.com Drives: THRSS #2 / CGM#1 Join Date: Jul 2006 Location: SA, Texas Posts: 24,416 View My Garage	Dude.....I'll take 15% better fuel efficiency any day. Add that to VVT and AFM and we've got a winner!!!!!!!!!!!! __________________

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