C7 Updates

[Rob]

As per Harlan Charles a short time ago, an official curb weight has not been determined yet.

As for a convertible and when it's coming.... "soon". Lol

Sent from my SCH-I535 using Tapatalk 2

 

[XLR8]

I'm keenly interested in two things:

1. a C7 convertible and

2. both body styles in the dark red - Crystal Red or whatever "new" dark red may be called.

Jane Ann

 

[C6 CRZN]

Jane Ann I would go with Crystal Red, not that I would know about that color.

 

[1analguy]

The February/March issue of Road & Track says the C7 base car's curb weight has come in at 3311 lbs...right about where the C6 GS was. They also said that the C7's welded/cast aluminum frame is 80 lbs lighter than the C6's hydro-formed steel frame, and that the C7's frame is stiffer than the C6 Z06/ZR1 aluminum frame. So far, though, no one has claimed that the C7 frame is stiffer than the C6 steel frame...

 

[Paul T]

Look for the convertible at the Genva show.

 

[Gorgon]

The February/March issue of Road & Track says the C7 base car's curb weight has come in at 3311 lbs...right about where the C6 GS was. They also said that the C7's welded/cast aluminum frame is 80 lbs lighter than the C6's hydro-formed steel frame, and that the C7's frame is stiffer than the C6 Z06/ZR1 aluminum frame. So far, though, no one has claimed that the C7 frame is stiffer than the C6 steel frame...

GM's statement is that the C7 frame is 99lbs lighter and 57% stiffer than the hydroformed steel frame of the C6.

 

[1analguy]

GM's statement is that the C7 frame is 99lbs lighter and 57% stiffer than the hydroformed steel frame of the C6.

Where the 19 lb discrepancy is coming from, I have no idea. R & T got their info from GM, too. If we were just wild-ass guessing without any input from GM, you might be tempted to say that since aluminum is roughly 1/3 the weight of steel, then the new frame should be roughly 1/3 the weight of the C6 steel frame...but that doesn't take into account how much weaker many alloys of aluminum are than even mild steel.

When replacing steel with aluminum, if strength is to be maintained, a larger volume of aluminum will be required...which will somewhat negate that "1/3-the-weight" advantage. Ever seen an aluminum connecting rod vs a steel one? When they did the C6 Z06/ZR1 frame in aluminum to save weight, they didn't really have any extra room for adding aluminum volume and so ended up with a frame that, even with it's top permanently-fastened, was not as stiff as the standard open-top C6 steel frame. In 1997, the C5's hydroformed steel frame was a marvel of strength/stiffness, and it's still very good, even by today's standards. I'll be amazed if that "57% stiffer" is, in fact, when compared to the hydroformed steel frame rather than the Z's aluminum frame. We've all seen those manufacturing photos of them welding and flipping the new frame around. It didn't look so different that the load paths will have changed radically, and it's an open-top frame with no support up high, too. I may be wrong, and I hope I am, but I remain skeptical...and not just about frame stiffness, as you'll see below:

Returning to the subject of weight, I'm also wondering why, when "every gram had to fight it's way onto the C7", did the base car end up weighing the same as a C6 Grand Sport? To hear them tell it, they not only peeled 80-99(?)lbs out of the frame, but considerable additional savings were also found in sub-frames and suspension components, the seats, narrower wheels/tires, carbon fiber replacing GRP, and their list probably goes on and on. The only place that they'll admit that a few pounds were added is in the LT1 vs the LS3, yet there's that 3300+ lb C7 curb weight anyway. Why? If they're really telling us the truth, then something is just not adding up... ;squint:

 

[steveb01z06]

You know one thing I don't remember seeing on any of these Corvette web sites? "What I'm willing to give up to keep the curb weight low." I've seen a LOT of postings about how GM had better do this or do that. The finest leather is mandatory. It can't be too noisy or I won't be able to listen to "Moonlight Sonata" while doing 120 mph. The windows have to have Express up or down. Electric heated and cooled seats. HUD. Cruise control. Smooth ride. Cup holders. Automatic dimming rear view mirror. GPS. Bluetooth. Massaging seats (OK, I made that one up). Nice carpeting. etc, etc.


All these things have to be wired up, except the noise insullation. It all adds up. I remember sitting in on a meeting with an aircraft completion shop rep who finally had to tell my compatriot who was like a kid in a candy store thinking of new ways to spend the stock-holders money on a new airplane that he had to draw the line some place because of room and weight. That new airplane was a slug compared to other similar airplanes with reasonable equipment lists. It took noticeably more power to make it fly at the same indicated airspeed and it climbed slower and didn't go as far on the same fuel.


So now people are shocked that the C7 weighs the same as the previous model (despite the fact that it's longer and wider)? I can't imagine why Chevrolet just didn't wave a magic wand and make it weigh 2500 lbs.

If you really place a priority on lightness and performance, then quit demanding a rolling home theater. The car that you thought you wanted could still be out there in the form of a track special, a Corvette ACR or Club Sport, if you like, but you'll have to give things up. The idea that one car can be everything to everybody is what gave the F111, and if you were a fan of the F111, my apologies, but it was 'way too big and heavy to be what it was meant to be.

I hope the C7 isn't Chevrolet's Aardvark.

 

[Rob]

I find the discussion about the C7's weight interesting.

There's something you're all forgetting: the C7 has larger wheels, larger tires, and larger brakes. That all means additional weight.

So while a frame may turn out to be lighter because of a change in materials, or increased use of carbon fiber body panels instead of steel or sheet molded composite, it doesn't necessarily mean the overall curb weight of the car is going to dramatically decrease.

If you want higher performance - in may instances, that high performance comes at a cost in curb weight? Why? Because of such things as larger wheels, larger tires and larger brakes.

Take a look at some of the exotics out there such as the Lamborghini Aventador or the Bugatti Veyron.....especially the Bugatti. With 1,000+ horsepower on board...you're going to need larger rubber to keep the car planted, which requires larger wheels. You're also going to need some pretty hefty brakes to be capable of pulling the car down from the speeds that car is capable of.

Last week, when I asked Harlan Charles about the official curb weight for the C7, he said they were not ready to release the number yet, and went on to explain that while they saved weight with the frame and carbon fiber body panels, they are also using larger wheels, tires and brakes which adds additional weight.

I cannot verify that the number Road and Track is reporting is accurate. I'm not saying they're right or wrong. I'm simply saying, I have yet to hear a number from GM. When I do, I'll report it here.

 

[steveb01z06]

I understand your point, but the fastest cars around a track have 13 inch wheels, not 20. Yes the brakes can be bigger, but wheels are driving the entire design. Width, not height, is going to enhance performance, and the new car has narrower wheels than the C5 or C6, at least on the front.

I still think that too much attention is being paid to things that maybe make a long weekend trip more enjoyable, but they do slow the car down and make it more expensive.

I'd like to see a hard-core performance version, and not by adding a SC and 300 lbs.

 

[Rob]

I understand your point, but the fastest cars around a track have 13 inch wheels, not 20. Yes the brakes can be bigger, but wheels are driving the entire design. Width, not height, is going to enhance performance, and the new car has narrower wheels than the C5 or C6, at least on the front.

I still think that too much attention is being paid to things that maybe make a long weekend trip more enjoyable, but they do slow the car down and make it more expensive.

I'd like to see a hard-core performance version, and not by adding a SC and 300 lbs.

I agree. But remember, they're building a sports car to appeal to a very wide array of people. Not all Corvette owners track their cars, or even have a desire to track their cars. I too would love to see them come out with a high performance, track-specific version as an option.

Who knows....maybe they will...

 

[steveb01z06]

I'm glad you are coming around to my way of thinking. But it is less likely to happen if the squeaky wheels are whining about how the Nav unit is obsolete, or the headliner is gauche.

If you go to a Lotus website, a bet the only discussion about entertainment systems is about how to remove them. It might happen (the track special) since they have a number of people on staff at Corvette with racing backgrounds, so I'm hopeful. It would be best to still be street-legal.

It couldn't possibly hurt the brand to have the equivalent of the GT3.

I'll admit that I'm probably not the mainstream customer, but look at how much attention the Z06 and ZR1's get. They are the Halo models of the Halo car, and I bet not many kids put posters up on their bedroom walls of base C6's.

 

[Rob]

I'm glad you are coming around to my way of thinking. But it is less likely to happen if the squeaky wheels are whining about how the Nav unit is obsolete, or the headliner is gauche.

If you go to a Lotus website, a bet the only discussion about entertainment systems is about how to remove them. It might happen (the track special) since they have a number of people on staff at Corvette with racing backgrounds, so I'm hopeful. It would be best to still be street-legal.

Or whether or not there's even going to be a Lotus. :L

 

[steveb01z06]

Someday there won't be a Lotus or a Vette. It was a pretty good time to be alive, but I think the pinacle is just about here.

 

[Rob]

Someday there won't be a Lotus or a Vette. It was a pretty good time to be alive, but I think the pinacle is just about here.

I don't think we'll lose the Vette any time soon, but I am disappointed in how things have turned out for Lotus. I liked what I saw with a couple of their new models, but due to poor management and severe mis-management of funds, I'm afraid we've seen Lotus' swan song. I hope I'm wrong.

 

[tankman]

I have a concern with the new C7's aluminum frame.

My concern revolves around strength. People make claims about aluminum's strength, which are usually exaggerated. Aluminum has better stiffness qualities, and people mistakenly take that as greater overall strength.

As I was standing infront of the new C7's frame at the Autoshow i couldn't help but notice the similarity between the fron section of the C7's frame to the front section of my C5's. I had a tree that snapped through that front impact bar like a pretzel. I shudder to think the results if it were 6061, or something with a lesser psi.

So my concern is that while it is the "correct" thing to do by making everything as light as possible, I hope the engineers didn't get too weight conscious in their designs.

Eric

 

[1analguy]

The base C7's wheels (and I imagine, tires) are the same diameter as, but narrower than, those of the C6 Grand Sport that it's weight is being compared to. I don't know for sure, but I'd be surprised if the C6 GS doesn't have front rotors that are larger than the front rotors on the base C7. I understand your points about interior/electronic amenities, but what have they added to the C7 in this regard that the C6 GS didn't have too?

I only raised the weight question in the first place out of curiosity, because the numbers don't seem to be adding up correctly. I'm one of those guys who wants the amenities and I don't care if the car weighs 3300 or 3000 lbs, because I figure that it comes with four wheels on it so I'll never have to carry it around...it'll be carrying me. I certainly hope that there will be a light-weight version for those to whom it does matter...but on the C6, the aluminum frame was the light version. Unless they are willing to deliver a car without any interior, where are they going to peel real weight out of a C7?

Someday there won't be a Lotus or a Vette. It was a pretty good time to be alive, but I think the pinacle is just about here.

That sort of thing is just impossible to predict. I have a 1976 issue of Hot Rod magazine in which Smokey Yunick is predicting that the small block Chevy will be totally and forever gone by 1978. And that man was nobody's fool. I just celebrated the 40th anniversary of my hiring at the American Motors plant in Kenosha, WI. I clearly remember that on the day that I started, people were telling me that the plant was going to close. And they were right too, it did close...in October of 2010! Sometimes these things will prove to have more lives than a cat...

 

[steveb01z06]

What makes me think the Vette will be gone (along with all other high-powered, large personal vehicles) has to do with acronyms: EPA, CAFE, and most recently, GAO. I'm sure you know that the EPA has been pushing for much higher CAFE standards, which is hardly friendly to powerful cars. And just last Friday, the GAO issued a report that stated that the current economic situation in the US is "unsustainable" and if not corrected will result in the "collapse of the dollar." This, also, will be bad for big, powerful cars, along with just about everything else.

So, I actually feel kind of stupid talking about something as inconsequential as the empty weight of a car that could be the swan song of GM, but it's also possible this won't happen. But when the GAO errs, it's usually on the side of optimism.

 

[1analguy]

Do you know if the new CAFE standards are still averaged over a company's entire fleet? If they are, then there may still be a glimmer of light at the end of the tunnel for the Corvette. It's such a small percentage of GM's total sales. The Viper may be in the same situation, too. Chrysler's sales are a lot smaller than GM's, but they hardly sell any Vipers in comparison to the Corvette's sales...

 

[Rob]

Do you know if the new CAFE standards are still averaged over a company's entire fleet? If they are, then there may still be a glimmer of light at the end of the tunnel for the Corvette. It's such a small percentage of GM's total sales. The Viper may be in the same situation, too. Chrysler's sales are a lot smaller than GM's, but they hardly sell any Vipers in comparison to the Corvette's sales...

I believe they are.