VVT Gen IV looming...

I'm surprised nobody has posted this already (excluding yours truly)...

GM Demonstrates Future Technologies to Improve Future Powertrain Efficiency

MILFORD, Mich. – General Motors today demonstrated to automotive journalists a host of advanced powertrain technologies it is developing to both reduce emissions and improve the efficiency and performance of its internal combustion engines, automatic transmissions and hybrid systems.

The company also revealed technical details on several new products scheduled to debut in 2006, including new variants in the Gen IV small-block V-8 engine family; six-speed automatic transmissions; and the hybrid system for the 2007 Saturn VUE Green Line, the latest model in GM’s broad hybrid portfolio.

The new powertrains are part of GM’s goal to roll out 50 new, more efficient and powerful engines and transmissions by the end of the decade – a plan GM Powertrain Group Vice President Tom Stephens revealed in September 2004.

“The continued refinement, advancement and application of internal combustion engine and transmission technology, as well as the rollout of hybrids, are part of GM's advanced propulsion technology strategy,” said Stephens. “Through these advancements, GM continues to reduce emissions and improve fuel economy as the company marches toward the long-term goal of producing hydrogen fuel cell-powered vehicles to remove the vehicle from the environmental debate.”

Technological progress enables advanced combustion concepts
As part of his presentation, Stephens said that many of the technologies under development today will enable GM to produce engines featuring advanced combustion systems like Homogeneous Charge Compression Ignition, or HCCI.

On Aug. 16, GM announced an initiative with Bosch and Stanford University researchers to accelerate the development of HCCI. GM officials also announced a goal to develop and demonstrate the viability of a HCCI engine concept within the next few years.

HCCI is a combustion technology that uses compression ignition rather than spark ignition to initiate the combustion process, resulting in higher efficiency and lower NO x emissions compared to a normal spark-ignition or diesel engine.

While the joint program will focus on the controls, sensors and actuators necessary to facilitate the combustion system, GM Powertrain engineers are developing the engine technology necessary to accommodate the advancements and make HCCI commercially viable.

“The technologies we are developing today – gasoline direct injection, Displacement On Demand, variable valve actuation and variable valve timing – all deliver incremental improvements to engine efficiency,” said Stephens. “But more importantly, they are the building blocks to mass-producing engines that can operate with advanced combustion systems like HCCI.”

New engines benefit from advanced technologies today
While many of the advanced technologies demonstrated to journalists were for future, unspecified powertrains, the new powertrains GM is launching today benefit from fuel-saving and performance enhancing features, like Displacement On Demand and variable valve timing.

“The new variants of Gem IV small-block V-8 are a perfect example of applying advanced, fuel saving technology to a high-volume of powertrains today,” said Stephens.

Multiple variants of the new small-block engines feature Displacement On Demand, as well as variable valve timing (VVT). Displacement On Demand seamlessly alternates the engine between eight- and four-cylinder operation, improving engine efficiency by as much as 12 percent in some vehicles.

Variable valve timing optimizes engine performance by continuously adjusting intake and exhaust valve timing in relation to the crankshaft. The introduction of variable valve timing in these engines is the industry’s first application of VVT on a mass-produced V-8 overhead valve engine.

Complete details of the new engine variants will be provided at a later date.

Six-speed automatics deliver improved efficiency, performance
In addition to improving engine efficiency, GM is launching a broad portfolio of advanced six-speed automatic transmissions to increase overall powertrain performance.

“During the next five years, GM will launch 10 new automatic six-speed transmission variants," said Stephens. "In fact, by 2010, GM will be producing more than three million six-speed transmissions per year."

GM six-speed automatic transmissions use a wide gear ratio spread to improve both performance and fuel economy over traditional four-speed automatics.

GM will launch seven of the six-speed automatic variants in North America and Europe . These include rear-wheel variants of the new Hydra-Matic six-speed, which debuted with the Hydra-Matic 6L80 in the 2006 Chevrolet Corvette and Cadillac STS-V and XLR-V. Also included in the new rear-wheel drive six-speeds is a new Allison 1000 six-speed, introduced in the 2006 Chevrolet Silverado HD and GMC Sierra HD pickups.

Rounding out the seven variants is the new front-wheel drive (FWD) Hydra-Matic 6T70 six-speed automatic transmission. The 6T70 is one of the industry’s most advanced FWD six-speed transmissions and is scheduled to debut in the all-new 2007 Saturn Aura midsize sedan.

Innovative hybrid systems enhance vehicle efficiency, provide broad consumer choice
In addition to improving the efficiency of conventional engines and transmissions, GM is in the midst of rolling out three innovative hybrid powertrain systems. The company plans to integrate the systems in up to 12 vehicle models, providing consumers a broad portfolio of hybrid systems that will vary in fuel economy savings and cost.

GM currently produces hybrid technology for diesel transit buses – 364 of which are on the road in 25 cities around the United States . The company also produces the Silverado and Sierra hybrid trucks – the world's first full-size hybrid pickup trucks.

According to Stephens, General Motors is now gearing up to launch the belt alternator starter system, an affordable hybrid system that will deliver good fuel economy savings. Saturn will be the first to debut the system, in mid-2006, when the 2007 Vue Green Line is introduced.

"The refinements GM is making to internal combustion engines and automatic transmissions today provides added efficiency benefits to GM's future hybrid powertrains,” he said. “With GM’s hybrid system in the Saturn Vue Green Line we expect consumers to get a real payback on their initial investment over the life of the vehicle.”

GM has also announced that it is co-developing an all-new, uniquely compact and scalable two-mode full hybrid drive system with DaimlerChrysler. This new two-mode full hybrid will initially launch in GM’s new Chevrolet Tahoe and GMC Yukon SUVs in 2007.

"Through the last 30 years in North America, we've improved our gasoline car fuel economy by as much as 130 percent and our gasoline truck fuel economy by as much as 75 percent," said Stephens. "We'll continue this trend of significant improvements by applying these and other engine and transmission technologies around the globe."

http://media.gm.com/servlet/GatewayServlet?target=http://image.emerald.gm.com/gmnews/viewpressreldetail.do?domain=2&docid=17541

woo woo! :thumb: ™

Watch for HCCI engines. Very good stuff.

This is all great news to hear. :)

Keep it up GM. Leading technologies in Powertrains is where it will be at. Make or Break.

It looks like there are some exciting things in the upcoming future. I like the idea of a six speed automatic transmission.

Sounds great, but I doubt I'm the only one getting tired of hearing what GM "will" do. :(

and the hybrid system for the 2007 Saturn VUE Green Line, the latest model in GM’s broad hybrid portfolio.

What did I miss? :confused:

Looks like VVT will be one of the things helping the 5.3L reach 355HP/380tq in the GMT900's

I'd guess it is, but I didn't see the article mention if it was intelligent VVT or 'dumb' VVT. The most current gen of VVT systems in Honda and Toyota vehicles takes into account driver habits, throttle position, speed, shift points, etc and not just a cut-off RPM to determine if and when to switch to the second cam profile.


Regardless, I was hoping GM would focus more on variable valve actuation and not just VVT. With VVA (if they could implement it reliably), they wouldn't just be getting with the times, they'd be FAR surpassing it.

Infinitely and instantly variable cam timing with inherent DOD. Niiiiiiiiice. Do it GM!:D

Sounds great, but I doubt I'm the only one getting tired of hearing what GM "will" do. :(


Nope.

I dunno, this whole article or news brief reads like a recent history overview only with future tense used. Phrases like "GM _will_ be the first to introduce this new g-wiz system on vehicles produced in 2007" are nothing but marketing hype. The beginning of 2007 is still 1.5 years away, let alone the fact that there are 12 months of 2007 to be considered. Unless GM is keenly awear of ALL of their competitor's plans, it seems rash to make statements to what GM will be first to do 1.5-2.5 years from now.

I'd guess it is, but I didn't see the article mention if it was intelligent VVT or 'dumb' VVT. The most current gen of VVT systems in Honda and Toyota vehicles takes into account driver habits, throttle position, speed, shift points, etc and not just a cut-off RPM to determine if and when to switch to the second cam profile.

There is no second cam profile. The VVT system uses a cam phaser to adjust the cam's timing relative to the crankshaft. This phasing is continuous and will take into account all the usual things like vehicle load, throttle position, etc.

Of course, since there's only one cam the intake and exhaust valves all have to move at the same time and in the same direction, but this system still provides about 80% of the benefits of a full-blown VVT system.

I hope they come out with a !VVT! elimintor i like having all 8 always one demand :p

jk, this is very good news. More power while still meating emissions :thumb: GM.

Sounds very interesting, to bad most of it is atleast a model year away. I would love to see them put a 350hp VVT 5.0L with a choice of either 6spd auto or manual into a car that starts with a "Z" and ends with a "28" ;) . Though I would also love to have one of those 6spd autos for my '56 Chevy. That would be bad as hell :headbang: .

David

I hope they come out with a !VVT! elimintor i like having all 8 always one demand :p

jk, this is very good news. More power while still meating emissions :thumb: GM.

VVT is Variable Valve Timing. That has nothing to dow ith Displacement On Demand, or DoD which shuts down 4 cyls while crusing.

I'd guess it is, but I didn't see the article mention if it was intelligent VVT or 'dumb' VVT. The most current gen of VVT systems in Honda and Toyota vehicles takes into account driver habits, throttle position, speed, shift points, etc and not just a cut-off RPM to determine if and when to switch to the second cam profile.


Regardless, I was hoping GM would focus more on variable valve actuation and not just VVT. With VVA (if they could implement it reliably), they wouldn't just be getting with the times, they'd be FAR surpassing it.

Infinitely and instantly variable cam timing with inherent DOD. Niiiiiiiiice. Do it GM!:D

I have a 2.4L SS Cobalt with the VVT. It doesn't do sqaut for peak hp or torque. It's hard to feel it kick in, very sublte. Too sublte.

I do have a real flat torque curve though. Other then that it sounds like its best for reducing emmsions. I'd like a more aggresive system.

Peak numbers aside, I did race a Beretta GTZ and I beat him by more then 0.5 sec despite having less hp

Whatever happened to the twin cam in block (pushrod) engine they were showing a couple of years ago?

Nothing, that is what happened to it. Its a shame too, it was a nice engine. Probably costs too much to build to justify it.

Nothing, that is what happened to it. Its a shame too, it was a nice engine. Probably costs too much to build to justify it.

Why do you say that it was a shame? It did have some neat features, but it seemed too complicated -- wasn't it something like seven spinning shafts or something (maybe I'm thinking of a different engine).

I don't know, unless it had some important advantage over the VVT DOD Gen IV, I don't see the need for it.

Remember the W8 from Volkswagen? It was a nice engine too. But complicated and low on power . . . . Their new VR6 has more power, less fuel consumption, and is likely cheaper to build.

Why do you say that it was a shame? It did have some neat features, but it seemed too complicated -- wasn't it something like seven spinning shafts or something (maybe I'm thinking of a different engine).

I don't know, unless it had some important advantage over the VVT DOD Gen IV, I don't see the need for it.

Remember the W8 from Volkswagen? It was a nice engine too. But complicated and low on power . . . . Their new VR6 has more power, less fuel consumption, and is likely cheaper to build.
The XV8 was a 75° V8 and would easily have been made modular for a powerful V6. The 4.3L V8 equaled the 5.7 in hp and torque despite its smaller displacement and physical size. Also the XV8 had 3 valve cylinders, DI, and true VVT because it had separate intake and exhaust camshafts. XV8 may just have been what GM has up its sleeves should the current lineup of OHV V8s have a hard time keeping up with the OHC V8s in the future.

I have a 2.4L SS Cobalt with the VVT. It doesn't do sqaut for peak hp or torque. It's hard to feel it kick in, very sublte. Too sublte.

Do you want VVT to feel like a bad transmission?

I can't really feel the VVT on my Colorado either. I've driven CTS, TrailBlazers, BMW M3's with VVT and non of them "kicked". Although the M3's 333HP inline 6 did pick up a lot of steam on the high RPMs and was gutless below 3K

VVT doesn't 'kick in or our', it's always operating, changing the timing of the cams and valves.

To get compression ignition from regular gas, doesn't the compression ratio have to be in the 20's to 1, or somewhere insanely high?

VVT doesn't 'kick in or our', it's always operating, changing the timing of the cams and valves.

Yeah, Honda's VTEC system "kicks in", because it not only varies the timing, but has a completely different cam lobe for high rpm. A standard VVT system just plays with timing through the rev range.


To get compression ignition from regular gas, doesn't the compression ratio have to be in the 20's to 1, or somewhere insanely high?

It would depend more on dynamic compression ratio, not static. You can get compression ignition (detonation) in a gasoline motor at a lower static compression ratio than that.

cool. Now I can put VTEC stickers on my new Camaro. :D

Why do you say that it was a shame? It did have some neat features, but it seemed too complicated -- wasn't it something like seven spinning shafts or something (maybe I'm thinking of a different engine).

I don't know, unless it had some important advantage over the VVT DOD Gen IV, I don't see the need for it.

Remember the W8 from Volkswagen? It was a nice engine too. But complicated and low on power . . . . Their new VR6 has more power, less fuel consumption, and is likely cheaper to build.

You are completely right from a business standpoint. It was a nice piece of engineering though, and I am not aware of any other engines that feature two cams in the block (there could be though). Having two camshafts in the block, one for intake and one for exhaust, would allow for full variable valve timing, as opposed to the system GM will be using that just advances or retards the timing based on rpm.