C7 Weight Issues
Melting Slicks
Joined: Apr 2007
Posts: 2,508
Likes: 71
From: round rock tx
Joe -- the rest of your analysis flows from the part I copied above, which, unfortunately is an oversimplification. While the Z06 gets its 505 HP @ 6300 RPM (and torque peak of 470 @ 4800 RPM) that does not mean the LT1 will be 55 HP (10%) less all the way from 4K to 6.3 K RPM, especially if the LT1 has identical torque @ 4K RPM! The fall off will be gradual -- quite possibly unnoticeable until about 4.8K to 5K RPM or so. Depending on the gear ratios, then, you could be essentially tied for the first 2.5 seconds getting to 40, which would put the C7 wheel to wheel. At that point, the Z should begin losing the C7, but possibly only for a portion of the 4K-7K (or whereever the optimum shift points turn out to be).
And, building off what the one poster suggested, 99% of the time the "fun" accelleration, for 90% of Z AND C7 owners, is probably in the 2K to 5K RPM range anyway. Given what we know today (not that much) indications are there is no significant difference in what the engines will produce in that range.
And, building off what the one poster suggested, 99% of the time the "fun" accelleration, for 90% of Z AND C7 owners, is probably in the 2K to 5K RPM range anyway. Given what we know today (not that much) indications are there is no significant difference in what the engines will produce in that range.
Interesting. You enjoy your car at 2k rpm? In my 11 z06 I don't start smiling until around 4k rpm anyways. Anything under that feels like cruising.
Le Mans Master
Joined: May 2010
Posts: 7,756
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From: Ventura CA
Team Owner
Joined: Sep 1999
Posts: 41,732
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From: Springfield MO
Funny that people that actually drive a C6 Z06 with the LS7 all say the same thing. "At 4,000 RPM, all hell breaks loose with my LS7".
Last edited by JoesC5; Jan 25, 2013 at 08:57 PM.
Instructor
Joined: Nov 2010
Posts: 206
Likes: 0
With LS7, 5-6k there is a feeling for a split second, that the power will never stop climbing in linear fashion.
However, the worry is the exponential valve guide wear at higher rpm.
I was surprised at the 0-60 13 shelby, given the tire width and weight distribution. but the technology was there to compensate.
I suspect the c7 will have similar launch technology, and the ride quality and handling must necessarily be exceptional, otherwise the c7 Stingray just would not make sense.
However, the worry is the exponential valve guide wear at higher rpm.
I was surprised at the 0-60 13 shelby, given the tire width and weight distribution. but the technology was there to compensate.
I suspect the c7 will have similar launch technology, and the ride quality and handling must necessarily be exceptional, otherwise the c7 Stingray just would not make sense.
Burning Brakes
Joined: Oct 2012
Posts: 933
Likes: 3
From: Dallas, TX
Um... unless you're saying you would be OK with the C7 being SLOWER than the C6, then I think you need to take another gander at my post and the one I'm replying to... I don't think you understood.
Last edited by RocketGuy3; Jan 25, 2013 at 09:54 PM.
Racer
Joined: Feb 2012
Posts: 456
Likes: 2
I think the chart of the LT1 is the truck chart and the car chart may have a little more spice to it. "Due to the added torque of the new V-8 engines, new 9.5- or 9.76-inch rear axles are used." http://www.topspeed.com/cars/chevrol...-ar130323.html
9.76 axles? or ring gear?
9.76 axles? or ring gear?
Last edited by CitationZ06@yahoo; Jan 25, 2013 at 10:05 PM.
Thread Starter
Le Mans Master
Joined: Oct 2004
Posts: 6,813
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From: Toronto Ontario Canada
All I can say is wait until the first production models are out and there are some real test reviews of these cars. I truly do believe GM engineering is hustling right now to get these cars in under 4 seconds. Nobody on this forum has tested one of these cars so don't fall for the hype. I hope they succeed but if they don't you can count on the facts being stretched a bit to accomocate expectations. It has happened before.
Last edited by b4i4getit; Jan 25, 2013 at 10:12 PM.
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Thread Starter
Le Mans Master
Joined: Oct 2004
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From: Toronto Ontario Canada
Race Director
Joined: Mar 2007
Posts: 11,331
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From: Missouri City Texas
It might help if you looked at the engine dyno graphs for the LS7 and the LT1.
They don't lie.
LS7...
LT1...
The LT1's torque does not keep climbing above 4,000 RPM nor does it's horsepower climb above 5900 RPM.
5000RPM...LT1 is 440 lbs-ft and LS7 is 470 lbs-ft
6000RPM...LT1 is 390 lbs-ft and LS7 is 450 lbs-ft
6500RPM...LT1 is 360 lbs-ft and LS7 is 420 lbs-ft.
7000RPm...LT1 is zero lbs-ft and LS7 is 390 lbs-ft
The horsepower curve also shows the superiority of the LS7.
4,000RPM...LT1 is 340HP and LS7 is 300 HP
5,000RPM...LT1 is 420HP and LS7 is 410 HP
6,000RPM...LT1 is 445HP and LS7 is 500 HP (55HP delta)
6,500RPm...LT1 is 365HP and LS7 is 505Hp (140 HP delta)
7,000RPM...LT1 is zeroHP and LS7 is 500HP.(500 HP delta)
These are GM's dyno graphs. Do you not think GM knows how to operate a dyno?
I don't believe you are capable of grasping the concept that some engines are designed for low end torque and some for high end horsepower. The LT1 was designed for excellent low end torque with out giving up too much on the top end. The LS7 was designed for great low end and high end torque to deliver the horsepower. Just because two engines have 450 lbs-ft of torque at 4,000 RPM doesn't mean they will have the same torque at 6500 RPM (and surely not the same horsepower at 6,500 RPM).
They don't lie.
LS7...
LT1...
The LT1's torque does not keep climbing above 4,000 RPM nor does it's horsepower climb above 5900 RPM.
5000RPM...LT1 is 440 lbs-ft and LS7 is 470 lbs-ft
6000RPM...LT1 is 390 lbs-ft and LS7 is 450 lbs-ft
6500RPM...LT1 is 360 lbs-ft and LS7 is 420 lbs-ft.
7000RPm...LT1 is zero lbs-ft and LS7 is 390 lbs-ft
The horsepower curve also shows the superiority of the LS7.
4,000RPM...LT1 is 340HP and LS7 is 300 HP
5,000RPM...LT1 is 420HP and LS7 is 410 HP
6,000RPM...LT1 is 445HP and LS7 is 500 HP (55HP delta)
6,500RPm...LT1 is 365HP and LS7 is 505Hp (140 HP delta)
7,000RPM...LT1 is zeroHP and LS7 is 500HP.(500 HP delta)
These are GM's dyno graphs. Do you not think GM knows how to operate a dyno?
I don't believe you are capable of grasping the concept that some engines are designed for low end torque and some for high end horsepower. The LT1 was designed for excellent low end torque with out giving up too much on the top end. The LS7 was designed for great low end and high end torque to deliver the horsepower. Just because two engines have 450 lbs-ft of torque at 4,000 RPM doesn't mean they will have the same torque at 6500 RPM (and surely not the same horsepower at 6,500 RPM).
Notice that it says "preliminary" and "estimated" for the torque and horsepower.
I'm not even sure who you're arguing with, actually....who said that the LT1 would match the LS7 in torque?
We get it. You drive a Z06, get over it
Race Director
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From: CA
Burning Brakes
Joined: Feb 2004
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From: McKinney TX
I think that's the point the OP is making-- that he thinks they are still trying to figure a way to get the new car to back up these potential numbers-- that they may have a weight problem that needs to be addressed with pound shaving or a better tune.
Melting Slicks
Joined: Jun 2005
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St. Jude Donor '12-'13-'14, '16
He is guessing about specs based on a rumor. not concered at all.
Drifting
Joined: Sep 2007
Posts: 1,348
Likes: 733
From: Oceanside Ca
It cracks me up , when the first sketches we saw of the C7, most disliked it. Now if someone on the C7 forum states they do not like any aspect of the C7 they are either too old or just bitter because they own anything but a C7.
Now the latest thing is the C7 will out perform a Z06. Ha, some think a base C7 will out perform a ZR1. I think you guys are lost your ability to reason.
Now the latest thing is the C7 will out perform a Z06. Ha, some think a base C7 will out perform a ZR1. I think you guys are lost your ability to reason.
Burning Brakes
Joined: Oct 2012
Posts: 933
Likes: 3
From: Dallas, TX
Dude... I'm really at a loss for words. Are you seriously this cluelessly pessimistic? Or is this some new form of subtle trolling?
It's not a "probably". It is a GUARAN-FREAKIN-TEE.
I would bet my manhood, if not my life, that that C7 will be faster than the C6 in literally every single measurable category.
... Getting a 0-60 in at under four seconds in a $50-60K sports car in the year 2013 is not that difficult to believe. At all. It's not hype. If anything "under 4" is a conservative estimate on their part. There is literally NO way GM would have over-promised on that.
It's not a "probably". It is a GUARAN-FREAKIN-TEE.
I would bet my manhood, if not my life, that that C7 will be faster than the C6 in literally every single measurable category.
... Getting a 0-60 in at under four seconds in a $50-60K sports car in the year 2013 is not that difficult to believe. At all. It's not hype. If anything "under 4" is a conservative estimate on their part. There is literally NO way GM would have over-promised on that.
Last edited by RocketGuy3; Jan 26, 2013 at 12:53 AM.
Safety Car
Joined: Aug 2000
Posts: 3,510
Likes: 43
From: Tulsa OK
It cracks me up , when the first sketches
we saw of the C7, most disliked it. Now if someone on the C7 forum states they do not like any aspect of the C7 they are either too old or just bitter because they own anything but a C7.
Now the latest thing is the C7 will out perform a Z06. Ha, some think a base C7 will out perform a ZR1. I think you guys are lost your ability to reason.
we saw of the C7, most disliked it. Now if someone on the C7 forum states they do not like any aspect of the C7 they are either too old or just bitter because they own anything but a C7.
Now the latest thing is the C7 will out perform a Z06. Ha, some think a base C7 will out perform a ZR1. I think you guys are lost your ability to reason.
All that being said, I am still glad I bought my 427 vert in December. I will be driving that car while everyone else is waiting on their new one. I got a great discount and the C7's will be going for MSRP. In three years, who knows what I will be driving, maybe a C7.
I did not like the rear end of the C6 when it came out either, but I have bought two of them...it grew on me. In the end, regardless if it's a C1 or a C7, or anything in between, we are all driving or going to be driving Corvette's, the greatest sports car for the money on earth.
Stop bashing each other and go drive your car.
Safety Car
Joined: Dec 2006
Posts: 4,642
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From: Dalllas/Ft Worth Area TX
GM really has a challenge!
I'm NOT trying to get into any "shouting" matches or anything similar. I believe that we are now approaching the limits of two wheel drive and it will take ALL THE SKILLS that we have to launch the car to lower the ET's, and weight, as we all know, is a major problem. That is NOT saying that we can't lower the ET's BUT it is becoming even more difficult with ALL the goverment regulations and requirements. At some point GM is eventually going to have to concede that for them to lower the ET's, they will have to use another platform for propulsion; that is: AWD or a mid engine platform OR both. Let's just hope that upper management wants to keep the Corvette alive AND competitive.
Of course, I'm not even trying to bring in the other varables which make lower ET's even more of a problem. The magazines will definitely point out ET's that are not competitive with other exotic cars that are also affected by the following:
1. Air temperature,
2. Type of road surface,
3. Tire compound,
4. Tire pressure,
5. Altitude,
6. Humidity,
7. Weight, and
8. So on, etc.
I'm NOT promoting a change in the platform BUT only trying to point out that it is NOT going to be easy at this point in the C7 development to shave alot of weight off. GM is doing a great job in "stretching" out the "racing" technology they are now using, RWD, etc. The "hills" or challenges are even getting more difficult! GM, keep up the GOOD WORK!
Of course, I'm not even trying to bring in the other varables which make lower ET's even more of a problem. The magazines will definitely point out ET's that are not competitive with other exotic cars that are also affected by the following:
1. Air temperature,
2. Type of road surface,
3. Tire compound,
4. Tire pressure,
5. Altitude,
6. Humidity,
7. Weight, and
8. So on, etc.
I'm NOT promoting a change in the platform BUT only trying to point out that it is NOT going to be easy at this point in the C7 development to shave alot of weight off. GM is doing a great job in "stretching" out the "racing" technology they are now using, RWD, etc. The "hills" or challenges are even getting more difficult! GM, keep up the GOOD WORK!
Last edited by 2006c6keller; Jan 26, 2013 at 04:58 AM.
Team Owner
Joined: Feb 2001
Posts: 27,252
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From: Short Hills, NJ
I would bet my manhood, if not my life, that that C7 will be faster than the C6 in literally every single measurable category.
... Getting a 0-60 in at under four seconds in a $50-60K sports car in the year 2013 is not that difficult to believe. At all. It's not hype. If anything "under 4" is a conservative estimate on their part. There is literally NO way GM would have over-promised on that.
... Getting a 0-60 in at under four seconds in a $50-60K sports car in the year 2013 is not that difficult to believe. At all. It's not hype. If anything "under 4" is a conservative estimate on their part. There is literally NO way GM would have over-promised on that.
The car might not be 'C6 Z06 fast' of course, but it WILL be at the very least a little faster in every single performance/handling/braking category than a base (or even Grand Sport) C6 LS3. 