Spaceframe or Monocoque (split from MSNZ)

[Goat Boy]

Originally Posted by CDM

No irony there as a V8ST is also a spaceframed vehicle...

No they are not, they are monocoque!

[Swedish Brick]

Hmmmm looks pretty spaceframeish doesn't it?

[Goat Boy]

Originally Posted by Swedish Brick

Hmmmm looks pretty spaceframeish doesn't it?

Guess it doesn't actually - from the V8ST website:

In more detail:

The V8 SuperTourer is based on a monocoque chassis, like the Australian V8 Supercar car of the future (COFT project),and built to accommodate both the current VE Commodore and FG Falcon bodies or any other similar sized four-dour production vehicle such a Toyota Camry, BMW 5 series, etc.

Designed and built by Paul Ceprnich, of Pace Innovations Australia, the chassis forms the basis of a future-proofed V8 touring car, similar in concept to a current Australian V8 Supercar but at less than half the cost.

[Swedish Brick]

But the CoTF is a spaceframe.

That chassis picture shows a spaceframe car. How much chassis strength does the body add to that car?

How is Supertourer built? Starts as a pile of steel bars welded into a frame with some panels tacked on the outside is about it isn't it?

That line from the website doesn't really make sense when you consider the meaning of monocoque and the concept of accommodating multi bodies.
In a monocoque car the body IS the chassis and frame.
In that case to be a different car (Holden, Falcon etc) the frame/chassis needs to be different.
But all the Supertourer cars have the same chassis. Just different body panels.

How many layers are there to those panels? Looks like outer layers (1) only.
If you sliced open a production body you will find many layers of panels to add strength hence allowing it to be a monocoque. None of which is in that car.

[Goat Boy]

Well you can argue all you like but I believe them, they should know.

[Woolley]

Originally Posted by Swedish Brick

In a monocoque car the body IS the chassis and frame.

The tub, I think, which can still have body panels affixed to it. But apart from that utter pedantry I'm inclined to agree with you. There's a lot of frame and space on that chassis.

[Goat Boy]

What do the regulations say it is?

[Goat Boy]

Can you have semi-monocoque, like a modern airliner I wonder?

[Mark Petch]

Originally Posted by Woolley

The tub, I think, which can still have body panels affixed to it. But apart from that utter pedantry I'm inclined to agree with you. There's a lot of frame and space on that chassis.

Hi Woolley,

Not wanting to appear to being pedantic here, but a V8 Supertourer is by any definition a Monocoque Chassis. It starts life with steel panels welded together to form stress bearing members, including the front and rear chassis rails, the role cage is built in a completely separate rotary jig, for accuracy reason, and then mounted to the monocoque structure.

In theory we could mount all the drive train and suspension etc to the basic monocoque, with out the rollcage structure, and drive it down the road. No question the roll cage adds a huge amount of stiffness to the finished chassis, just as any well designed roll cage does when you fabricate and weld one into a conventional road car.

Mark Petch.
Technical Director,
V8 Supertourers.

[Swedish Brick]

Originally Posted by Mark Petch

Hi Woolley,



In theory we could mount all the drive train and suspension etc to the basic monocoque, with out the rollcage structure, and drive it down the road.

$5 says it would fold it half trying to negotiate the driveway entrance

[smokin'joe]

Originally Posted by Swedish Brick

$5 says it would fold it half trying to negotiate the driveway entrance

must have a looksie at one up close, as i doubt the mounting points for the drivetrain are in the sheetmetal, but weld tabs/inserts etc off the tube frame sections ?

[Mark Petch]

Originally Posted by smokin'joe

must have a looksie at one up close, as i doubt the mounting points for the drivetrain are in the sheetmetal, but weld tabs/inserts etc off the tube frame sections ?

SJ, not so.

The engine is mounted off the upper box section of the fully fabricated sheet-metal front cross member and the rear of the engine is mounted Nascar style of the bellhousing ears that mount to a large 5mm thick sheet of Chrome-moly plate. The rear of the gearbox is bolted to the box section inner chassis rails. The 3 link rear suspension is bolted to the fully fabricated, Chrome-moly plate and box section rear baulk-head.

If you look at the photo's posted you will see the front suspension arms, lower and upper are bolted to fully fabricated Chrome-moly extension's of the front chassis rail's. The only tube work in either the front or rear suspension is the damper towers.

Mark Petch.
Technical Director,
V8 Supertourers.

[Woolley]

Originally Posted by Mark Petch

Hi Woolley,

Not wanting to appear to being pedantic here, but a V8 Supertourer is by any definition a Monocoque Chassis.

Be as pedantic as you like on that one. I've just learned something new, so thank you. I realise I know what monocoque means on a single seater, but not quite how it applied to a saloon.

[fredd1]

Originally Posted by Swedish Brick

$5 says it would fold it half trying to negotiate the driveway entrance

Hope you're taking notice of things that fold in the Oz Taxi Racing series.
Some structural weakness demonstrated there, yesterday.

[Swedish Brick]

Didn't catch it. What happened?

And for the record I don't think petchs definition of monocoque matches the dictionary version

[Goat Boy]

Originally Posted by Swedish Brick

Didn't catch it. What happened?

And for the record I don't think petchs definition of monocoque matches the dictionary version

I assume you think that because never ever in your whole life have you ever been wrong?

[Icarus_nz]

Spaceframe = Truss http://en.wikipedia.org/wiki/Spaceframe

Monocoque = Eggshell http://en.wikipedia.org/wiki/Monocoque

Semi-monocoque = truss stiffened by panels - read the second paragraph of the monocoque definition above

So you see, it matters not what your opinion is but rather how the load paths are managed.

Isn't engineering grand?

[Swedish Brick]

Thanks icarus, that's exactly my point.
Its a spaceframe with some welded panels in the front chassis rails. Hardly a text book monocoque and definitely not a monocoque as far as this (off)topic is conceri. Therefore no, you cannot enter a st in the si enduros

[Southern Man]

Originally Posted by fredd1

Hope you're taking notice of things that fold in the Oz Taxi Racing series.
Some structural weakness demonstrated there, yesterday.

I didn't notice any structural weakness but I did observe some excellent work of deformable structures doing as they are designed to do which is absorbing and dissipating energy

[Goat Boy]

Quote from Wiki spaceframe explanation for cars:

"In both a spaceframe and a tube-frame chassis, the suspension, engine, and body panels are attached to a skeletal frame of tubes, and the body panels have little or no structural function. By contrast, in a unibody or monocoque design, the body serves as part of the structure."

Given what Mark has just told you, how can you still argue that it is a spaceframe? Mark says you don't need the cage structurally and nothing is mounted to it, therefore it must be a (semi) monocoque.

Someone should enter an ST into the enduros and see how the MNZ rules people view it.

We are WAY off topic though now aren't we? Is it worth starting another thread on this? It's quite an interesting discussion.

[Mark Petch]

Originally Posted by Icarus_nz

Spaceframe = Truss http://en.wikipedia.org/wiki/Spaceframe

Monocoque = Eggshell http://en.wikipedia.org/wiki/Monocoque

Semi-monocoque = truss stiffened by panels - read the second paragraph of the monocoque definition above

So you see, it matters not what your opinion is but rather how the load paths are managed.

Isn't engineering grand?

Icarus,

I think you will agree that Wikipedia heading "CAR", under the subject matter, clearly illustrates the difference between a spaceframe car and a so called monocoque [unibody] car, which is what all most all production cars are as apposed to an aircraft fuselage.

Wikipedia-Cars
"Spaceframes are sometimes used in the chassis designs of automobiles and motorcycles. In both a spaceframe and a tube-frame chassis, the suspension, engine, and body panels are attached to a skeletal frame of tubes, and the body panels have little or no structural function. By contrast, in a unibody or monocoque design, the body serves as part of the structure".

[Goat Boy]

https://www.facebook.com/#!/photo.ph...type=3&theater
Now THAT is a spaceframe...

[Swedish Brick]

So by adding a few steel sheets in the front welded into box section that makes the car monocoque?
What is the body doing? Do those B pillars have the inner panels adding strength and stiffness? In fact are those B pillars anything more than just the outer panel?
Is the roof adding torsional strength or is that coming from the extensive spaceframe structure in the car?
Can someone please show me where "the body serves as part of the structure"

[socram]

Can we PLEASE shift spaceframe/monocoque discussion to a new thread? It isn't that difficult to start one.

[Goat Boy]

Originally Posted by Swedish Brick

So by adding a few steel sheets in the front welded into box section that makes the car monocoque?
What is the body doing? Do those B pillars have the inner panels adding strength and stiffness? In fact are those B pillars anything more than just the outer panel?
Is the roof adding torsional strength or is that coming from the extensive spaceframe structure in the car?
Can someone please show me where "the body serves as part of the structure"

Carefully re-read Mark's posts on the subject.