General Motors: Development and Technology News
01-17-2007, 01:00 AM
#41
Burning Brakes
Originally Posted by gavriil
Yes, but the OHV engines vibrate a lot. And for marques like Cadillac that's unacceptable considering how they want to compete now. Even for Buick.
My friend had an older 87 Mustang w/ the OHV 5.0L V8 and it never felt any rougher than his newer Mustang w/ the 4.6L SOHC V8. Is the vibration issue more of a problem w/ GM's OHV engines or all OHV engine designs?
01-17-2007, 01:24 AM
#42
Drives With Hands
Originally Posted by AlterZgo
I never knew vibration was such a problem in OHV engines. I was wondering why they used the LS6 and LS2 in the CTS-V, but not for the STS or STS-V.
My friend had an older 87 Mustang w/ the OHV 5.0L V8 and it never felt any rougher than his newer Mustang w/ the 4.6L SOHC V8. Is the vibration issue more of a problem w/ GM's OHV engines or all OHV engine designs?
My friend had an older 87 Mustang w/ the OHV 5.0L V8 and it never felt any rougher than his newer Mustang w/ the 4.6L SOHC V8. Is the vibration issue more of a problem w/ GM's OHV engines or all OHV engine designs?
01-17-2007, 11:21 AM
#43
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Originally Posted by titan
Again, Benz's 5.0L V8 was an old engine with relatively old tech; the new 5.5L is fairly new, and it'll be around for some time.
However, GM is late. So in order for them to compete, they take a HUGE leap with this next gen. V8. 400HP out of 5+ liters should be the first iteration. Unless if they follow MB's new strategy which is to offer two V8s. One smaller (say about 4.0L) and one larger (about 5.5L).
01-17-2007, 11:27 AM
#44
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Originally Posted by rmpage
It is really amazing how far GM has been able to push the OHV architecture.
I mean at 675HP, the 8.4L is pusing 81 horse per liter. Assuming the true peak HP of our CL/S' engine is 249HP, it only makes 78 horses per liter. And we're supposedly proud of it, even today. That's a feat in my book (for the Viper).
01-17-2007, 11:35 AM
#45
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Originally Posted by AlterZgo
I never knew vibration was such a problem in OHV engines. I was wondering why they used the LS6 and LS2 in the CTS-V, but not for the STS or STS-V.
My friend had an older 87 Mustang w/ the OHV 5.0L V8 and it never felt any rougher than his newer Mustang w/ the 4.6L SOHC V8. Is the vibration issue more of a problem w/ GM's OHV engines or all OHV engine designs?
My friend had an older 87 Mustang w/ the OHV 5.0L V8 and it never felt any rougher than his newer Mustang w/ the 4.6L SOHC V8. Is the vibration issue more of a problem w/ GM's OHV engines or all OHV engine designs?
Finally, the correct comparison is not how much did the 5.0L vibrated compared with the SOHC in the Stand, but how much more both of the above vibrate compared to, say, the 4.6L in the BMWs. Even comparing it to the 3.5L V6 in the TL Type S, you will find a huge difference (apparently that engine in the Acura is extremely smooth I understand).
01-17-2007, 11:36 AM
#46
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Whenever I drove in a Vette, my only complaint about the engine was the vibration issue. My secondary complaint was the lack of a satisfactory nuance from the sound coming at the top of the tach range. But that's nit picking.
01-17-2007, 01:30 PM
#47
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Originally Posted by gavriil
YEs. MB is slow to uprate engines but when they do it, they take big steps.
However, GM is late. So in order for them to compete, they take a HUGE leap with this next gen. V8. 400HP out of 5+ liters should be the first iteration. Unless if they follow MB's new strategy which is to offer two V8s. One smaller (say about 4.0L) and one larger (about 5.5L).
However, GM is late. So in order for them to compete, they take a HUGE leap with this next gen. V8. 400HP out of 5+ liters should be the first iteration. Unless if they follow MB's new strategy which is to offer two V8s. One smaller (say about 4.0L) and one larger (about 5.5L).
12-18-2008, 08:25 AM
#48
Senior Moderator
General Motors: New Direct-Injection Motors Announced
GM announces 30 mpg 2.4L direct-injection I4, plus new 3.0L V6
General Motors on Thursday announced its 2010 Chevrolet Equinox crossover will come equipped with a 2.4-liter direct-injection four-cylinder Ecotec engine delivering 180 horsepower at 6700 rpm and 172 pound-feet of torque at 4900 rpm. Perhaps most importantly, the engine promises to deliver 30 mpg on the highway. That tops Ford’s new 2.5-liter I4, which produces 170 hp and returns a highway EPA rating of 28 mpg.
GM also announced plans to offer the new Equinox with a 3.0-liter V6 delivering 255 horsepower and 214 pound-feet of torque. Also featuring direct injection, the motor has an isolated fuel injector system that promises quieter operation than other DI engines. Rubber isolators are used with the fuel rail to eliminate metal-to-metal contact that would otherwise transmit noise and vibration from the high-pressure fuel system.
“We first introduced direct injection in North America in the 2007 Saturn Sky Red Line and the Pontiac Solstice GXP,” said Tom Stephens, executive vice president, GM Global Powertrain and Global Quality. “We’ve been rolling out the technology across our portfolio as quickly as we can so that our customers will have additional fuel savings options. Direct injection is a state-of-the art engineering solution because it enables improved fuel economy and lower emissions without sacrificing power.”
General Motors on Thursday announced its 2010 Chevrolet Equinox crossover will come equipped with a 2.4-liter direct-injection four-cylinder Ecotec engine delivering 180 horsepower at 6700 rpm and 172 pound-feet of torque at 4900 rpm. Perhaps most importantly, the engine promises to deliver 30 mpg on the highway. That tops Ford’s new 2.5-liter I4, which produces 170 hp and returns a highway EPA rating of 28 mpg.
GM also announced plans to offer the new Equinox with a 3.0-liter V6 delivering 255 horsepower and 214 pound-feet of torque. Also featuring direct injection, the motor has an isolated fuel injector system that promises quieter operation than other DI engines. Rubber isolators are used with the fuel rail to eliminate metal-to-metal contact that would otherwise transmit noise and vibration from the high-pressure fuel system.
“We first introduced direct injection in North America in the 2007 Saturn Sky Red Line and the Pontiac Solstice GXP,” said Tom Stephens, executive vice president, GM Global Powertrain and Global Quality. “We’ve been rolling out the technology across our portfolio as quickly as we can so that our customers will have additional fuel savings options. Direct injection is a state-of-the art engineering solution because it enables improved fuel economy and lower emissions without sacrificing power.”
Sounds good.
Anyone else glad to see some auto news unrelated to bailouts and cancellations?
12-18-2008, 12:50 PM
#50
The sizzle in the Steak
Nice to see domestics going DI.
12-18-2008, 01:19 PM
#51
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2.4L with DI and only 172lbft of torque? hmm...that reminds me of the TSX which is also making that amount of torque at a lower rpm than 4900. I guess it's because it runs on regular fuel? Also 30mpg in a crossover sounds great!
The 3.0L engine is again kinda of low in torque? I think the new Ford 3.0L engine makes 223lbft. But it loses in the hp department.
The 3.0L engine is again kinda of low in torque? I think the new Ford 3.0L engine makes 223lbft. But it loses in the hp department.
12-18-2008, 02:36 PM
#53
The sizzle in the Steak
12-18-2008, 02:55 PM
#55
Senior Moderator
While the engines aren't groundbreaking its good to see that the gap between GM and the Japanese and Germans is no longer there or at least not nearly as big as it once was.
185HP 3.4L FTL.
185HP 3.4L FTL.
12-18-2008, 04:49 PM
#56
2G TLX-S
12-18-2008, 05:32 PM
#57
Race Director
...but DI is still too expensive for a regular sedan so they have to put it into a more expensive CUV. It does sound like GM is going forward with things that matter - just hope they're around to see their R&D come to some good.
12-26-2008, 05:34 AM
#61
isn't DI like a diesel setup where you have fuel injected in the cylinder it'self? I wonder what long term reliability of those injectors are going to be.......
12-26-2008, 06:52 AM
#62
I'm still baffled at how Honda hasn't figured this out yet. Nearly half the manufacturers out there have/are experimenting with DI with a lot of success.
12-26-2008, 09:04 AM
#63
Senior Moderator
Pretty much.... the main difference vs. regular fuel injection is that instead of injection fuel into the intake manifold, the fuel gets injected directly into the combustion chamber. I'm sure it'll be at least as reliable as diesels, if not moreso, because diesel is thicker than gas and DI gas engines won't have fuel at as high pressure as diesels. It still probably has externally mounted fuel rails, etc. plus I'm sure manufacturers have the sense to mount the injectors closer to the cool side (intake side) of the engine. I haven't actually seen a DI engine taken apart on a workbench just yet, but every diagram I've seen portrays them that way.
I'm still baffled at how Honda hasn't figured this out yet. Nearly half the manufacturers out there have/are experimenting with DI with a lot of success.
I'm still baffled at how Honda hasn't figured this out yet. Nearly half the manufacturers out there have/are experimenting with DI with a lot of success.
Direct injection requires higher fuel pressure than conventional fuel injected engines and an engine-driven high-pressure fuel pump is used to supply up to 1,740 psi (120 bar) of pressure. The system regulates lower fuel pressure at idle – approximately 508 psi (35 bar) and higher pressure at wide-open throttle.
12-26-2008, 09:46 AM
#64
Last I heard, they were working on it.
https://acurazine.com/forums/showthr...n+direct+honda
edit:
link doesn't work anymore.
https://acurazine.com/forums/showthr...n+direct+honda
edit:
link doesn't work anymore.
12-26-2008, 07:20 PM
#65
Pretty much.... the main difference vs. regular fuel injection is that instead of injection fuel into the intake manifold, the fuel gets injected directly into the combustion chamber. I'm sure it'll be at least as reliable as diesels, if not moreso, because diesel is thicker than gas and DI gas engines won't have fuel at as high pressure as diesels. It still probably has externally mounted fuel rails, etc. plus I'm sure manufacturers have the sense to mount the injectors closer to the cool side (intake side) of the engine. I haven't actually seen a DI engine taken apart on a workbench just yet, but every diagram I've seen portrays them that way.
I'm still baffled at how Honda hasn't figured this out yet. Nearly half the manufacturers out there have/are experimenting with DI with a lot of success.
I'm still baffled at how Honda hasn't figured this out yet. Nearly half the manufacturers out there have/are experimenting with DI with a lot of success.
I work for a cat dealer and diesel injectors go out all the time on engines....that's why i asked maybe the injectors are not up to honda's reliability standards?
12-26-2008, 10:53 PM
#66
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that's probably a reason. Honda experienced with DI with its K series engine before in the 1st gen Stream, and they got rid of it in the 2nd gen model. If I remember correctly those injectors are supplied a Bosch and I'd imagine Honda doesn't want to rely on that company too much.
12-27-2008, 04:12 PM
#67
I feel the need...
12-27-2008, 05:47 PM
#68
What's more impressive it the redesign of the Equinox ...http://www.autoblog.com/photos/2010-...uinox/1231613/
12-27-2008, 09:04 PM
#69
It's beautiful!! Makes me want to dump my cr-v
12-27-2008, 10:00 PM
#70
My wife has a 99 CR-V, w/ about 98,000. This seems to be a choice. But I hate that GM use OnSTAR for Navi. :sucks:
12-29-2008, 02:28 PM
#71
2G TLX-S
that's probably a reason. Honda experienced with DI with its K series engine before in the 1st gen Stream, and they got rid of it in the 2nd gen model. If I remember correctly those injectors are supplied a Bosch and I'd imagine Honda doesn't want to rely on that company too much.
12-29-2008, 03:50 PM
#72
The sizzle in the Steak
12-30-2008, 02:10 AM
#73
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Why does Honda have to build everything themselves ? No other auto makers build everything themselves. It works best to rely on component makers who are most experienced in the area and can do their jobs best, rather than thinning out the R&D funds to support many new programs that still have a steep learning curve to overcome.
).
12-30-2008, 04:53 PM
#74
2G TLX-S
except for ..... and brakes. Honda/Acura is known to have weak brakes.
12-31-2008, 04:53 AM
#76
2G TLX-S
Not so fast. The car is still too new on the road. Wait another six months or so and see if Honda has fixed it's infamous warping front rotor problem for this 4G TL.
01-01-2009, 09:33 AM
#78
Senior Moderator
But like everything else Honda ... who knows if Honda is going to come up with DI for real. I think the tech seems like an important step in the evolution of the internal combustion engine. We all know gas prices will eventually go back to $100+ / barrel, and the other car manufacturers will have to achieve EPA minimum fuel economy standards, so why is Honda not innovating in this area?
I suppose our skepticism will put on hold once Honda comes up with their 'next big thing' ... but until then, we are all just whining / speculating on what the next step is.
And I agree -- it's the 'Honda way' to do things on their own. They'll have to figure out how to do DI in a reliable way.
I suppose our skepticism will put on hold once Honda comes up with their 'next big thing' ... but until then, we are all just whining / speculating on what the next step is.
And I agree -- it's the 'Honda way' to do things on their own. They'll have to figure out how to do DI in a reliable way.
02-18-2009, 07:32 PM
#79
General Motors: High Performance Vehicle Operations Unit Scrapped
