Gen V announcement
12-07-2011, 08:39 PM
#81
Le Mans Master
In the case of the LS9 at least, isn't it a high-tech four-lobe design, supposed to be a more efficient supercharger?
Is it always-on, or is it clutched? Is there a good article on all the gory details of the supercharger?
.Jinx
Is it always-on, or is it clutched? Is there a good article on all the gory details of the supercharger?
.Jinx
12-07-2011, 09:56 PM
#82
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Yes, GM already has the know-how, yet still decided to switch to a supercharger instead of turbos. They have already made this decision once before, so I don't see why they would nullify all of their prior engineering with their current forced induction to switch to turbos. It would be nice, no doubt, but very much unlike GM. Of course, they did it with the Cobalt SS (started blown, went turbo later) but in that car they hadn't first tried and eliminated the idea of a turbo. The ZR1 began as a turbo and was switched during development. Regardless of the reason, GM decided the TVS was a better choice for the application.
12-07-2011, 10:14 PM
#83
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So... What ARE the conditions of start/stop working? I wouldn't have a problem with it (as others have said) as long as you can turn it off.
But to be completely fair, I've never driven a car with start/stop and if the transition is unnoticeable, it wouldn't bother me at all. But I can't fathom that this would be unnoticeable. You step on the gas, you still have to wait for the motor to start, wait for it to settle, and then you start to move... Sounds like there's at least a full second of waiting for the car to start moving. I'm sure with a manual transmission, the motor wouldn't ever stop if you're on a hill. But that would definitely worry me.
I just don't see them putting this system in if the car is a real manual. That would be so complicated and likely not worth it. We already know that this new motor is supposed to be far more efficient. I really don't think this is something they're going to force on the Corvette being that it's pretty much the only GM vehicle still optioned with a real manual transmission (aside from the CTS-V).
Ever driven one of these? Had one for 3 years. It still had turbo lag. GM claimed that it would have so little lag that it'd feel like driving a car with large displacement. No... Not at all. That car sucked. Made no torque, had to rev a lot to get it going, and the turbo kicked in around 3K RPM.
But to be completely fair, I've never driven a car with start/stop and if the transition is unnoticeable, it wouldn't bother me at all. But I can't fathom that this would be unnoticeable. You step on the gas, you still have to wait for the motor to start, wait for it to settle, and then you start to move... Sounds like there's at least a full second of waiting for the car to start moving. I'm sure with a manual transmission, the motor wouldn't ever stop if you're on a hill. But that would definitely worry me.
I just don't see them putting this system in if the car is a real manual. That would be so complicated and likely not worth it. We already know that this new motor is supposed to be far more efficient. I really don't think this is something they're going to force on the Corvette being that it's pretty much the only GM vehicle still optioned with a real manual transmission (aside from the CTS-V).
Ever driven one of these? Had one for 3 years. It still had turbo lag. GM claimed that it would have so little lag that it'd feel like driving a car with large displacement. No... Not at all. That car sucked. Made no torque, had to rev a lot to get it going, and the turbo kicked in around 3K RPM.
12-08-2011, 12:49 PM
#84
So... What ARE the conditions of start/stop working? I wouldn't have a problem with it (as others have said) as long as you can turn it off.
But to be completely fair, I've never driven a car with start/stop and if the transition is unnoticeable, it wouldn't bother me at all. But I can't fathom that this would be unnoticeable. You step on the gas, you still have to wait for the motor to start, wait for it to settle, and then you start to move... Sounds like there's at least a full second of waiting for the car to start moving. I'm sure with a manual transmission, the motor wouldn't ever stop if you're on a hill. But that would definitely worry me.
I just don't see them putting this system in if the car is a real manual. That would be so complicated and likely not worth it. We already know that this new motor is supposed to be far more efficient. I really don't think this is something they're going to force on the Corvette being that it's pretty much the only GM vehicle still optioned with a real manual transmission (aside from the CTS-V).
Ever driven one of these? Had one for 3 years. It still had turbo lag. GM claimed that it would have so little lag that it'd feel like driving a car with large displacement. No... Not at all. That car sucked. Made no torque, had to rev a lot to get it going, and the turbo kicked in around 3K RPM.
But to be completely fair, I've never driven a car with start/stop and if the transition is unnoticeable, it wouldn't bother me at all. But I can't fathom that this would be unnoticeable. You step on the gas, you still have to wait for the motor to start, wait for it to settle, and then you start to move... Sounds like there's at least a full second of waiting for the car to start moving. I'm sure with a manual transmission, the motor wouldn't ever stop if you're on a hill. But that would definitely worry me.
I just don't see them putting this system in if the car is a real manual. That would be so complicated and likely not worth it. We already know that this new motor is supposed to be far more efficient. I really don't think this is something they're going to force on the Corvette being that it's pretty much the only GM vehicle still optioned with a real manual transmission (aside from the CTS-V).
Ever driven one of these? Had one for 3 years. It still had turbo lag. GM claimed that it would have so little lag that it'd feel like driving a car with large displacement. No... Not at all. That car sucked. Made no torque, had to rev a lot to get it going, and the turbo kicked in around 3K RPM.
12-08-2011, 02:14 PM
#85
Safety Car
I know somebody who works in GM's testing and development for their engines from I understand it's still going to be a 6 L direct injection the funny thing is is the new model name for the engine will be LT1 and the LT4. The LT4 is a supercharged engine. that's what He told me. He actually has had hands on both motors breaking them down inspecting and everything. So that's what he told me and he also told me that the pictures that were recently posted of what the C7 is go to look like he set me a text saying you Want to know what the C7 is going to look like and he sent me those picture so I am quite sure what he says is true.
12-08-2011, 03:49 PM
#86
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Interesting
I know somebody who works in GM's testing and development for their engines from I understand it's still going to be a 6 L direct injection the funny thing is is the new model name for the engine will be LT1 and the LT4. The LT4 is a supercharged engine. that's what He told me. He actually has had hands on both motors breaking them down inspecting and everything. So that's what he told me
The drop from 6.2 lt to 6 lt is nothing in terms of loss of power due to the introduction of DI on the 6 lt. The 6 lt engine could easily surpass the current engine in all things, power and efficiency (eonomy) and that's just from DI.
As for the dialogue on GM not doing high technology; the chief engineer of the Vett is a systems engineering guy who did the calculations for the C5, showing how much a loss of one pound of weight was worth. He there by established the trade off between investing in weight loss vs benefit from weight loss. I'll bet he's got a more elaborate scheme and wider ranging scheme for the Vett as he is now CE. The point is that there is no free lunch in the world of physics. Everything is a trade off. The best engineered products show the best trade offs according to some criteria. The question, what are the criteria that are being used on the Vett? One that the CE and product manager constantly tout is value for the buck. You can bet that any feature must earn it's way onto the C7 Vett. I can recall a comment from the GM engine people some time ago that they could do 80% of the benefit of VVT with a push rod engine. That was before some of the new and clever methods of VVT utilizing a push rod engine. My point is, how much is that last 20% worth in benefits and how much do you have to pay to get it (both in $s and physical terms)?
Style is cheap someone said. It doesn't cost any more to build a good looking car than an ugly one. Performance costs, that's where the trade offs have to be made.
One last point, notice how much press the Jeep is getting for interior design, that's because of a decision made by the head honcho. GM doesn't have that kind of a head honcho. In fact, my advice to him is "don't speak in public, you're embarrassing the folks that put you in that job."
12-21-2011, 12:15 AM
#87
Le Mans Master
A lot of hate on here from people who probably have never driven a start/stop system...
I've driven them, at least with automatics. I don't know how a manual would respond, but as long as it was refined and seamless, why not, if it saves gas? It must be refined, not thrown into production, as some GM systems are.
I like the fact that the Corvette is fast and economical.
DoD - exhaust note could be a problem.
Just don't mess with my V8 engine configuration. No V6s.
Michael
I've driven them, at least with automatics. I don't know how a manual would respond, but as long as it was refined and seamless, why not, if it saves gas? It must be refined, not thrown into production, as some GM systems are.
I like the fact that the Corvette is fast and economical.
DoD - exhaust note could be a problem.
Just don't mess with my V8 engine configuration. No V6s.
Michael
12-27-2011, 03:02 AM
#88
Sr.Random input generator
We have huge mandated increases in fuel economy on the way. Start Stop will increase mileage by 5-6% That is a signigicant increase for ralatively low cost. I understand the average cost to implement it is ~$60 per point increase or about $300-360.
While the Corvette is low volume relative to total GM volumes, they will not likely bypass the increase without a good reason like NVH problems identified earlier. Sometimes government mandates cause changes to cars even if the customers don't want them.
I never asked for side airbags and don't want them. Which one you demanded to have them? Heck I didn't ask for a driver airbag and didn't want one. Which one of you demaded them? The increase in survivability for a belt and airbag is not that great compared to no belt versus no belt with an airbag. With seatbelts an airbag causes more injuries than a seatbelt alone in speeds just above airbag activation. They were originally designed for unbelted people. Why did I have to pay for them when I always wear a belt.
While the Corvette is low volume relative to total GM volumes, they will not likely bypass the increase without a good reason like NVH problems identified earlier. Sometimes government mandates cause changes to cars even if the customers don't want them.
I never asked for side airbags and don't want them. Which one you demanded to have them? Heck I didn't ask for a driver airbag and didn't want one. Which one of you demaded them? The increase in survivability for a belt and airbag is not that great compared to no belt versus no belt with an airbag. With seatbelts an airbag causes more injuries than a seatbelt alone in speeds just above airbag activation. They were originally designed for unbelted people. Why did I have to pay for them when I always wear a belt.
12-31-2011, 12:33 PM
#89
01-12-2012, 03:21 PM
#90
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I thought they were going to use the new 5.5L in the C7?
01-12-2012, 05:48 PM
#91
That was widely speculated because of the racecar's rules-mandated displacement, however I do not believe GM ever confirmed this. GM Inside News has been saying the Gen V will be 5.3 and 6.2L.
When GM added DI to the L92 truck engine in testing,they went from 403 to "over 450" hp, so I have high hopes that we might see 475+ hp from a 6.2L SIDI engine with vvt in Corvette trim, but we will have to wait and see.
When GM added DI to the L92 truck engine in testing,they went from 403 to "over 450" hp, so I have high hopes that we might see 475+ hp from a 6.2L SIDI engine with vvt in Corvette trim, but we will have to wait and see.
01-13-2012, 08:24 PM
#92
Team Owner
Some say that the 6.0L is actually 364 cubic inches and that the 6.2L is 376, but we're pretty much just splitting hairs at this point. 
And I sure do hope so! 
That was widely speculated because of the racecar's rules-mandated displacement, however I do not believe GM ever confirmed this. GM Inside News has been saying the Gen V will be 5.3 and 6.2L.
When GM added DI to the L92 truck engine in testing,they went from 403 to "over 450" hp, so I have high hopes that we might see 475+ hp from a 6.2L SIDI engine with vvt in Corvette trim, but we will have to wait and see.
When GM added DI to the L92 truck engine in testing,they went from 403 to "over 450" hp, so I have high hopes that we might see 475+ hp from a 6.2L SIDI engine with vvt in Corvette trim, but we will have to wait and see.
And I sure do hope so!
