CLEAN

A unibody, by definition, has the body being an integrated structural component of the vehicle (which means metal body panels welded together). Thats the reason why the quarters on the 4th gen remained metal while all the other panels, sans the hood, could be made from lighter composites. The quarters were part of the unibody structure, while the other panels were not.

In the Corvettes case, the car cannot be a unibody because the composite/fiberglass/smc panels cannot bear a structural load. All of those panels are bolted to the structure underneath. The Corvette can be driven w/ none of the body panels attached.

Where you may have confused the C4, was that its frame rails were made from different pieces welded together to make a full frame. The birdcage structure was added to support the body, not the other way around. It wasn't until the C5 that you got a full length, one piece frame rail that ran the length of the car.

A space frame is something else entirely, look at Lambos, Ferraris, and dune buggys for those. They have nothing to do w/ frame rails or unibodys.

91_z28_4me

C5 & C6 are spaceframes, look at all the literature. The C5 can be driven without any body panels but so could the Fiero, S-series Saturns, Saturn Vue and the Lotus Elise. Any space frame car can be driven without body panels. The frame rails don't make the C5/6 a spaceframe but they do provide most of the body rigidity.

CLEAN

Spaceframe cars don't have frame rails. Corvettes are not spaceframes, nor are they unibodies, as you posted earlier.

Edit: interestingly enough, while just now doing research on this, I found a DANA site that has a picture of a Z06 frame that two engineers are holding up, and they're calling it a space frame, even though they're holding it up by its framerails, which spaceframes don't have. Interesting. W/ this kind of stuff out there, I guess I can understand the confusion.

Here is the definition of spaceframe (Dune buggy)
A space frame is a truss-like, lightweight rigid structure constructed from interlocking struts in a geometric pattern. Space frames usually utilize a multidirectional span, and are often used to accomplish long spans with few supports. They derive their strength from the inherent rigidity of the triangular frame; flexing loads (bending moments) are transmitted as tension and compression loads along the length of each strut.

Unibody (Camaro)-
a construction technique that uses the external skin of an object to support some or most of the load on the structure. This stands in contrast with using an internal framework (or truss) that is then covered with a non-load-bearing skin.

Body on Frame (Corvette)
Body-on-frame is an automobile construction technology. Mounting a separate body to a rigid frame which supports the drivetrain was the original method of building automobiles, and its use continues to this day.

91_z28_4me

Find me a reliable source that says that space frames cannot have tubular members acting as frame rails. Go ahead. If GM who developed 4 separate space frames, Dana who you provides the aluminum for the Z06 space frames, and Alcoa all call the C5/C6 structure a space frame who are you to tell them they are wrong?

SunsetHawkSelena

well, yes, actually. 91-96 b-bodies (impala, caprice, roadmaster, fleetwood) were full frame cars... that's why they can tow 5,000 lbs. (well the fleetwood can tow 7,500). long live b-bodies! i love my roadmaster

i know the new Camaro will be unibody as all new cars are these days... i'm just busting your ***** a little

91_z28_4me

The frame was the same as the 80s model B-bodies. As are the current Panther cars. The frames just don't need any updating so the manufactures figure why bother.

Fbodfather

wellalrighty then!

Lotsa misunderstandings in this thread, methinks.

The C4 had a frame. It also had what I'd refer to as a space frame.........now...I think it's a matter of semantics.....

The C4 had a roll cage of sorts......and the frame was one of the reasons it had such a high step-in -- which wasn't unlike a rebirthing experience to get in and out of the vehicle.

The C5 and C6 have frames -- the frame rails are hydro-formed.

But.........I'll solve this one by sending the thread over to an engineer who worked on C4 and C5....how's that???

91_z28_4me

You could just ask him. I think that we can all take your word to the bank after the 12 Billion "Have Faiths" you told us.

guionM

Wasn't sarcastic. Was answering a question with a question.

No worries.

BTW: the 91-96 B-bodies are on frames engineered in the mid 70s for the downsized GM B bodies. The frame was 20 years old when the B bodies were retired in '97. Newest "real" BOF cars were the GM G-bodies from GM (1978) and then the Ford Panther chassis (1979).

Save the hairsplitting going on with the C5 (which I can see how it might be considered a deviation on BOF.... so I'll give on that one) there's been no new BOF cars since the 70s. Save rebodied versions of those old chassis.

Fbodfather

'cept trucks!!!

Fbodfather

OK kids.........from an engineer......who worked on both C4 and early C5:

The C4 was more of a hybrid - the body panels were bonded onto the frame - panels weren't load bearing, like in a monocue construction. The body was then lowered, at marriage, onto the chassis with body mounts joining everything together. So it wasn't a body on frame - it was a frame with a body. The body structure was intergral with frame. When we did the vert, we cut the roof and stiffened up the frame and then reintroduced those features back into the coupe.

The C5 & 6 were changed by adding the back bone construction. I believe those can be made into a rolling chassis and are true space frames. And a space frame does include frme rails. Another example of this is, excuse the expression, Viper.


So there!

SunsetHawkSelena

thanks, Scott, but i'm a little confused now. isn't a "frame with a body" a unibody? or is it something between unibody and full frame? i'm not busting your *****, i really am confused.

ahh, see... you learn something new everyday. i had no idea when the frame for my b-body was designed, thanks i do love having a big car that can tow. i wish GM still made 'em so one day i could get a new one.

Good Ph.D

I think what hes saying is essentially that the passenger compartment was built in a unibody style and then attached to a frame like you would have on a BOF, thats two pieces.

A unibody is just one piece, you throw the axles, engine and trans on and you're ready to go.

CLEAN

I stand corrected! But a C4 still wasn't a unibody .

GRNcamaro

i think what he was trying to say is the body of the c4 was built on a frame and the front section and rear section of the frame where bolted to the middle part with the body built on it, but i could be wrong. i had a c4 and saw the front and back sections but never took a look at the middle