Club Cobra
Page 1 of 2 1 2
Show 20 post(s) from this thread on one page

Club Cobra (http://www.clubcobra.com/forums/)
-   ALL COBRA TALK (http://www.clubcobra.com/forums/all-cobra-talk/)
-   -   Chassis rigidity (http://www.clubcobra.com/forums/all-cobra-talk/131815-chassis-rigidity.html)

Tim7139 12-04-2014 12:52 PM
Chassis rigidity
 
While I've seen a lot of information on the subject, has there been any hard test data on the rigidity/flex of the more popular platforms such as SPF, ERA, Contemporary, FF, BD ?
Anybody care to grid them less to more, etc. etc.

PSB 12-04-2014 01:25 PM
Do a search http://i24.photobucket.com/albums/c4.../deadhorse.gif

Tim7139 12-04-2014 01:32 PM
Quote:
Originally Posted by PSB (Post 1328521)
I did a search, in fact several. I get snippets here and there but not anything comprehensive. What am I missing ?

PSB 12-04-2014 01:37 PM
This subject is almost as controversial as the "Real" subject, and brings just as many unsubstantiated "expert" opinions. The only difference is the FFR guys usually lead the delusional charge :JEKYLHYDE

The truth is there is no real data out there to make a comparison.

xlr8tr 12-04-2014 02:09 PM
what about the aussie guys where I think they have to show chassis rigidity data before they can register the vehicle?

DanEC 12-04-2014 03:51 PM
Car manufacturers are reporting torsional and bending rigidity for their frames/bodies all the time but I suspect most of it is derived from mega-buck super computers, finite element analysis and all that stuff. Small, custom, fabricators are not going to have access to that for the most part. Some assumptions and even rough calculations can be made looking at the structural properties of the main frame rails, number of crossmembers, etc. The structural properties for 4 inch round tube, 4 x 3 inch tube and 2 x 4 inch tube of specified thickness and steel grade are easy enough to come up with and I think if someone had the time they could make a ranking from that - but it would have some limitations.

Dimis 12-04-2014 04:43 PM
Quote:
Originally Posted by Tim7139 (Post 1328519)
While I've seen a lot of information on the subject, has there been any hard test data on the rigidity/flex of the more popular platforms such as SPF, ERA, Contemporary, FF, BD ?
Anybody care to grid them less to more, etc. etc.
Quote:
Originally Posted by xlr8tr (Post 1328528)
what about the aussie guys where I think they have to show chassis rigidity data before they can register the vehicle?
True... Our compliance process requires this, its mandated into the hoops of fire that need to be jumped through.

However, despite this, I doubt the information is held in one place.

Further I doubt the kits requested above are circulating in Aus without modification. I'm not aware of any ERAs or BDRs (for example) in standard guise that are getting around...

It would be interesting though... and I'd hazard a guess and say I wouldn't expect any of the US made kits to come close to the Aussie kits on this level.

john chesnut 12-04-2014 08:14 PM
What are the Aussie requirements and how do they test the car/frame?

Tommy 12-04-2014 08:26 PM
John,
I'm not sure their chassis standards would work up here -
http://cnet4.cbsistatic.com/hub/i/20...fb84/car_1.jpg

john chesnut 12-04-2014 08:40 PM
Thanks Tommy. :)

letsboogie351 12-04-2014 09:12 PM
Beam and Torsion test
 
Here is a guide from Australia. If you are that way inclined and have the skillset to build a jig you can do your own test

reading commences on page 6

http://www.google.com.au/url?sa=t&rc...JJ8z6NOkbWZnIg

AL427SBF 12-04-2014 09:14 PM
Quote:
Originally Posted by Dimis (Post 1328545)
... and I'd hazard a guess and say I wouldn't expect any of the US made kits to come close to the Aussie kits on this level.
I expect JBL would cruise through aussie regs in flying colors, in excess of 4800 lbs per degree torsional stiffness done on a chassis weighing 418 lbs :LOL:
.

strictlypersonl 12-05-2014 06:10 AM
Chassis design logic

Dimis 12-05-2014 06:25 AM
Quote:
Originally Posted by AL427SBF (Post 1328572)
I expect JBL would cruise through aussie regs in flying colors, in excess of 4800 lbs per degree torsional stiffness done on a chassis weighing 418 lbs :LOL:
.
True. JBL is impressive, but when you consider our minimum is 4000nm per degree, the JBL really ain't the bench mark now... Wouldn't you agree?

Particularly when you consider some ICV kits here are quoted in at reaching over 30,000nm per degree. Though I can't claim to know their weight for the sake of comparison.

vector1 12-05-2014 08:57 AM
Quote:
Originally Posted by Dimis (Post 1328593)
True. JBL is impressive, but when you consider our minimum is 4000nm per degree, the JBL really ain't the bench mark now... Wouldn't you agree?

Particularly when you consider some ICV kits here are quoted in at reaching over 30,000nm per degree. Though I can't claim to know their weight for the sake of comparison.
I think you have to consider the frequency also. Don't understand it all but the JBL was measured at 24 Hz minimum, I've seen different frequencies listed for whatever the test produce considerable difference in numbers. Maybe Richard will chime in.

vector1 12-05-2014 09:02 AM
Quote:
Originally Posted by strictlypersonl (Post 1328592)
That is an interesting article. One of the diagrams is very similar to the JBL.

DanEC 12-05-2014 11:29 AM
Quote:
Originally Posted by strictlypersonl (Post 1328592)
I will vouch that the ERA chassis seems very rigid, especially for an open car. :)

strictlypersonl 12-05-2014 11:38 AM
Quote:
Originally Posted by Dimis (Post 1328593)
True. JBL is impressive, but when you consider our minimum is 4000nm per degree, the JBL really ain't the bench mark now... Wouldn't you agree?

Particularly when you consider some ICV kits here are quoted in at reaching over 30,000nm per degree. Though I can't claim to know their weight for the sake of comparison.
The problem with a Cobra replica that is a close visual copy of the original is that it it totally restricted by what will fit "under the skin". We are very limited by the space necessary for the driver and engine, in what is really a pretty tiny package. The JBL skirts this a little by being a little creative with the original dimensions. i.e. wider and longer.
In addition, this is an open car. Cars with roofs have a big structural advantage.

john chesnut 12-05-2014 12:16 PM
My home built frame. I kept the stock body dimensions.


http://i1143.photobucket.com/albums/...eOnlyFront.jpg

Tim7139 12-05-2014 01:59 PM
Guys, with all due respect, however interesting this may be, it's got little to do with the initial post. I am very familiar with what's possible and theoretically what's desirable. I was more curious about what's out there on a more less relative bassis.
It sounds like nothing in the way of any testing and / or ratings have ever been done, lots of "seat of the pants" type stuff.


All times are GMT -7. The time now is 05:54 AM.
Page 1 of 2 1 2
Show 20 post(s) from this thread on one page

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: