Does anyone know if the C7 will be body on frame or unibody construction or what ever Porsche and Ferrari use. From the looks of the spi pics I say body on frame. I think if they went with what the compention use it will add weight but also a good stiff chassis that will improve ride and handling.

 

A unibody is folded sheet metal without a front-to-rear frame. It's a flex-mobile.

Body-on-frame is a unibody on a front-to-rear frame. A porkster.

The Corvette has a fiberglass bodywork on a steel girder frame. The bodywork only has to be a wind fairing and so most of the weight can go into the frame strength. (Only the C4 Corvette had the entire front bodywork hinged but that helps make the point.)

The Lotus Elise has a fiberglass bodywork on rectangular aluminum extrusions with cross-sections turned up tall-wise. The frame is in three sections and then bonded. Of course structual bulkheads are likely between the sections.

The Ford GT has a triangulated frame of aluminum extrusions. A large section of the rear bodywork is hinged.

The Ferrari 460 has aluminum extrusions with riveting and then an aluminum shell bodywork attached. The Lamborghini Gallardo is similar. Riveted extrusions is not exactly an automated machine folding and pounding out a unibody.

Porsche is a unibody but probably body-on-frame.

But a vehicle unibody is not truly a stressed skin because the fenders of a car are just bridging space and not really gusseting. The only thing that matters is the frame. If the bodywork is heavy then that's just wasted weight.

But here's how a unibody works. There's a sub-frame at the front suspension. There's extra thickness sheet metal at the rear suspension. There are heavy duty rocker panels made out of folded sheet metal. And then these three things are tied together by sheet metal floorpan and roof. Compare to the Corvette hydroformed girder frame that runs from front suspension to rocker panel to rear suspension in one piece.

But in general what is a unibody and what is not ? A unibody has some amount of bodywork that can't be removed by a mechanic. A non-unibody has bodywork that can be removed by a mechanic. In most cars that we know, the roof and the rear fenders can't be removed and that's a unibody.

There are cars with girder frames and then bodywork bolted or riveted to the frame and they call themselves space frames. They are not unibodies. They are claiming to be stressed skin. But even here the stressed skin advantage is not very much and the frame is what matters the most. Cars with fiberglass bodies have bodywork supported by the frame and don't claim to be stressed skin.

 

I think it will be VERY similar to what we have right now, hydroformed frame extrusions of steel (or aluminum?) with the body bolted/fused to it.
Simply because it works VERY well.

 

Best way to build them. Plus it wouldn't be a Corvette if it wasn't a plastic car. Also take more damage than metal cars and are easier to repair.

Bill

 

I saw an interview a year or two ago of a GM exec that talked about the near-future advancements in weight reduction would be in attachment technology. It was about how they would connect many of the pieces of a car together using fewer metal nuts, bolts, gusseting, etc that added unnecessary weight, using new epoxies and other kinds of materials welding technologies.

 

Corvette's chassis technology is among the best available. Corvette is affordable, strong, safe, and lightweight. Read All Corvettes are Red for the story of its development, and look for articles on C5's release and C6 Z06's release to learn just how advanced it is.

I look forward to learning how C7 refines the state of the art. High-strength steel? Aluminum alloy? More magnesium? More refined thickness and shape? New bonding techniques?

.Jinx

 

These weight reduction/bonding technologies are what I think will be most revolutionary about the C7.

 

I'm sure it will remain the same. Don't fix what's not broken and works well.

 

Sorry, that isn't what Corvette is about. Corvette is about advancing the breed. Weight reduction to get a better power to weight ratio is the next frontier.

 

 

While that's true, I just think that they don't need to change the way the corvette is built just to say its new and innovative, or build it the way the compitition does when in fact the way they're built is a better design.

 

I expect evolution in this department rather than radical change. The basic current ingredients are pretty darned good.

 

Wow you know your stuff, very impressive and informative!!!

So how does GM fix the forever & embarassing problem they have with creaking? I know all cars flex a little but I have never seen a modern car with as much creaking (especially over angled driveways) as the Corvette?

Hope they fix this once and for all in the C7....the CREAKING has to go!!

 

Thanks for the info. I was thinking of how my C3 was constructed when talking body on frame.
I am hoping that there will be as a big of a differance in construction between the C6 and C7 as there was between the C4 and C5. I would think GM will push the envelope as much as they can while still keeping the car in the same price range.

 

Ok what about the suspension? Transverse leaf springs or coilovers?
Corvette is the only sports car I know of that still uses leaf springs. Now if that was the best way to go then others would be using them also. I just would like GM to make great improvements to the Corvette. I have loved these cars for the past 30 years (I'm 40) and even though I could not swing a new C7 if GM makes a big leap with it maybe it will drive down the price of used C5 and C6s even more for me.

 

I hope they go to coil-overs. Would make for logical next step with a whole new platform.

 

You have creaking, in a C6?
Wow, my C6 is drum tight/rock solid under all weather conditions (had it out just tonight in 35 degree temps actually) and entirely squeak/rattle free.
All of the C6s that I've been in (I think roughly 12 different ones at this point) were the same exact way too.
My C4 had a couple but that was only over bad bumps while the roof was out.

 

I would think the creaking is related to the plastic body panels.

 

To get rid of most of the creaking, GM needs to stiffen the top of the car--much like the Z06. Making the top of the car carry structural loads would make the whole chassis significantly stiffer in bending and in torsion.

 

You must have the steel frame C6 and not the aluminum framed Z06.....my Z06 creaks in the street/driveway transition.