Mindless speculation ...

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Dec 27, 2002 | 03:19 PM

#21

Duck916

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From: Various places in Southern California.

Re: Mindless speculation ... (Scissors)

Quote:

According to the Ferrari guys, the C5's chassis is aluminium. :lol: That's news to me!

Which Ferrari guys are you speaking of? Maybe they think this because our $45K C5s are lighter than their $200K Ferraris?

Dec 27, 2002 | 09:28 PM

#22

Jinx

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From: Oakland, CA

Re: Mindless speculation ... (Duck916)

Wild speculation: the hydroformed frame rails could have identical exterior dimensions and still be of different wall thickness and construction details for different materials. This could allow (1) using steel for one vehicle and aluminum for another, or more likely (2) initial production in steel with a later change to aluminum.

In other words, it could be that the frame design for XLR/C6 is calculated for aluminum, and steel is an interim step or fallback position. There has been a lot of speculation about GM's new developments in both aluminum hydroforming and variable-thickness hydroforming.

Has it been positively confirmed that the still-not-yet-available-for-sale XLR frame rails will be steel?

.Jinx

Dec 30, 2002 | 07:59 AM

#23

Curtis A. Franz

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From: Prescott AZ

Re: Mindless speculation ... (Jinx)

"Has it been positively confirmed that the still-not-yet-available-for-sale XLR frame rails will be steel?"

I believe it has been said that they will be steel. Others are expecting a running change when the C6 shows up a year later. Like some have said, we will have to wait and see. :chevy

Dec 30, 2002 | 08:51 AM

#24

Scissors

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From: Virginia

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St. Jude's Donor '06

Re: Mindless speculation ... (Duck916)

Quote:

Which Ferrari guys are you speaking of? Maybe they think this because our $45K C5s are lighter than their $200K Ferraris?

There was a thread a while back with a link to a Ferrari forum and one of the things that kept coming up in this Corvette vs. Ferrari thread there was that the C5 has an aluminium frame (which, of course, it doesn't).

Dec 30, 2002 | 11:31 PM

#25

Duck916

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From: Various places in Southern California.

Re: Mindless speculation ... (Jinx)

Quote:

It's pretty unlikely that the frame rails would be designed with identical exterior dimensions for steel and aluminum. It might be possible, but it wouldn't make much sense. Due to aluminum's different properties, the designer would be needlessly hamstringing the design to remain with the same exterior dimensions.

Look at bicycles--steel bikes almost always have fairly narrow diameter tubes, while aluminum bikes have much larger tubes. This is done to take advantage of aluminum's properties while keeping the bike as light as possible.

Jan 1, 2003 | 01:40 PM

#26

Curtis A. Franz

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From: Prescott AZ

Re: Mindless speculation ... (Duck916)

Well this was another post inspiring topic by Mr. DifeQ. His list of "mindless" possibilities is much longer than the list of what we know, unfortunately. This lends a whole new definition to the Runge Kutta method heretofore unknown to me. My differential equations was way back in 1960 as was my first Corvette.

:chevy

Jan 6, 2003 | 12:09 AM

#27

VetNutJim

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From: Atlantis

Cruise-In I Veteran

Re: Mindless speculation ... (Curtis A. Franz)

Just a thought ..but..

Couldn't the aluminum frame provide the required rigidity and torsional resistance by increasing the thickness on the INSIDE of the frame tubing??

This could easily be done with the CAD software available.

This way the frame outside dimensions would not have to change and the frame could be hydroformed from steel or aluminum with a simple change in the hydroform machine control programming.

I'm no rocket scientist but I did stay in a Holiday Inn Express last night.

Jan 6, 2003 | 01:23 AM

#28

SWCDuke

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Re: Mindless speculation ... (VetNutJim)

Quote:

Just a thought ..but..

Couldn't the aluminum frame provide the required rigidity and torsional resistance by increasing the thickness on the INSIDE of the frame tubing??

Yes, but the walls would have to be considerably thicker in order for the final part to have the same stiffness, which would add so much weight that aluminum's weight advantage would be mostly negated. Increasing section size would be a much more effective way to maintain stiffness without as much weight, but then you compromise packaging.

Thicker walls would also raise issues with the hydroforming process itself because thicker walls' greater strength would reduce formability and thicker sections would likely be less ductile.

There are no silver bullets! Steel is a tough material to beat in an automotive structural application. Compare the NSX and Ferrari F355/F360 with their all aluminum structures to the Corvette. Despite a much larger engine and all steel sturcture, the Corvette is only marginally heavier, and if you only consider the Z06 model, all weigh within a hundred pounds, or three percent of each other.

Duke

[Modified by SWCDuke, 10:30 PM 1/5/2003]