Question to Engineering types: Is this a RWD chassis??

This doesn't look like a W-chassis or a Sigma, it's too big to be an Espilon, and it's not a Truck:

http://wieck.com/public/*2PV_052074

What is it? Anyone??

Originally posted by guionM
This doesn't look like a W-chassis or a Sigma, it's too big to be an Espilon, and it's not a Truck:

http://wieck.com/public/*2PV_052074

What is it? Anyone??

I'm not an engineering type exactly, but it looks like it might have a tunnel for a transmision and driveshaft heading the the rear.

Looks like an exhaust tunnel. You can also see how little space there is between the spare tire notch in the trunk and the backseat floorpan for a drive axle. Additionally, there is no place to mount a transmission crossmember, and if you look at the spacing up front, it appears to be a FWD engine cradle.

Other "did you know" points:
- The display behind him reads "A new offering in the industry's largest segment" "The new Malibu will hold ..."
- There is a blue Malibu off to the left in the background.
- Going by a different picture, the chassis off in the background on the right is also a Malibu.

So it is my guess that the chassis on the rotisserie is also... a Malibu.

You must have better resolution on your computer than I do, I can't see any of those background things. :(

I can only make out the Malibu on the left in the background..that's if...

http://www.machined.net/~chris/malibu_chassis/

So I guess it's an Epsilon.

Looks FWD or AWD to me. There's no clearance in the tunnel for a transmission. Also note the mounting point for struts, where as I'd expect GM to do something with an SLA setup for a RWD platform.

Those look like some strong frame rails...

I am impressed that they've figured out a way to package true frame rails in an unibody structure...built in SFCs!

GM was doing that type of massive hydroformed rail in a unibody back in the 1st-gen Aurora. In this particular case, I wouldn't be surprised if they're used in anticipation of a drop-top model.

Well, those don't look too massive to me first of all, and I thought C5 was the first to use hydroformed rails?

Not trying to be nit-picky, just trying to clarify.

Originally posted by Chris 96 WS6
Well, those don't look too massive to me first of all, and I thought C5 was the first to use hydroformed rails?

Not trying to be nit-picky, just trying to clarify.

Isn't there a difference? I thought the C5 was technically body on frame with the hydroformed frame rales...much like teh Trailblazer and Canyon?

Wouldn't that make these cars technically the same?

If cmc, Z284ever, and Eric are right, then those frame rails are probally needed for the drop top Grand Am replacement.

Originally posted by formula79
Isn't there a difference? I thought the C5 was technically body on frame with the hydroformed frame rales...much like teh Trailblazer and Canyon?

Wouldn't that make these cars technically the same?

Yeah, that is a big diff in how the cars are made, but hydroformed rails are hydroformed rails, regardless of the application they are used in. I just remember what a big deal it was (a lot is said about it in All Corvettes Are Red) that the C5 was the first production use of hydroformed rails. If the Aurora got smaller versions for use in a unibody chassis, then we have to revise Corvette history a little bit to say "first use of hydroformed rails in a body on chassis design".

Hydroforming is a metalforming technique, nothing more. It's just like stamping, extruding, vacuum casting, forging, etc., but yet people see the term "hydroform" and they think it's some new spectacular platform design. Smart unibody design uses whatever technique is "best" for forming the various parts, and there's a lot more going on than just hydroforming or stamping.

Don't go rewriting history just yet - I may not have been 100% correct in saying that the first-gen Aurora used hydroformed rails (it did use a hydroformed engine cradle and dashboard beam, but a few minutes of online research failed to turn up any clues on the construction method of the rails). Regardless of how they were made, the first-gen Auroras were extremely robust platforms, and possibly the first GM FWD that was truely world-class.