The list: Torsional Rigidity

[Mr. M]

Re: Torsional Rigidity

Great post Mirage77.

Im surprised the Phaeton is so much more rigid then the A8.

Rob...its quite simple really. Torsional rigidity is defined as:

Get it now?

From my rudimentary understanding though, the more rigid a chassis is the less chassis flex exists thus better withstanding the stresses caused by the drivetrain and other forces acting on the vehicle (road bumps etc.). It also provides a better foundation for absolutely precise suspension tuning. Or maybe I'm talking rubbish.

Thanks for the insight Mr. M...

So it seems that torsional rigidity would give a better ride quality as well.

 

[Mr. M]

Re: Torsional Rigidity

Ok its been done


I wonder if there are any numbers for a Formula 1 ?

I've seen them being thrown around, but not a consolidated list. Will keep a lookout.

 

[SDNR]

Re: Torsional Rigidity

Rob...its quite simple really. Torsional rigidity is defined as:

Get it now?

From my rudimentary understanding though, the more rigid a chassis is the less chassis flex exists thus better withstanding the stresses caused by the drivetrain and other forces acting on the vehicle (road bumps etc.). It also provides a better foundation for absolutely precise suspension tuning. Or maybe I'm talking rubbish.

Thanks for this Mr. Einstein.

BTW, aren't aluminum bodies generally stiffer than steel ones?

Also, has anybody got the figures for the Rolls-Royce Phantom DHC?

 

[Mr. Mercedes]

Re: Torsional Rigidity

Thanks for this Mr. Einstein.

BTW, aren't aluminum bodies generally stiffer than steel ones?

Also, has anybody got the figures for the Rolls-Royce Phantom DHC?

lol...I think I may be talking rubbish, but that's my inferred understanding about the subject. Could somone who really knows what they're on about please explain? Google isn't much help.

I also thought aluminium would be stiffer than steel, which is why im quite perplexed about the A8 vs. Phaeton.

 

[Mr. M]

Re: Torsional Rigidity

BTW, aren't aluminum bodies generally stiffer than steel ones?

Also, has anybody got the figures for the Rolls-Royce Phantom DHC?

I thought so too, can someone explain the metal characteristics?

I'll try finding the DHC numbers... But since it's a new car, it's quite difficult.

 

[Zafiro]

Re: Torsional Rigidity

Also, has anybody got the figures for the Rolls-Royce Phantom DHC?

I searched for it but no numbers, the pressrelese from RR just say almost as rigid as ....

 

[Mr. Mercedes]

ok heres what I found on google:

torsional rigidity

A vehicle body’s resistance to twisting forces

In the world of physics, just about any word beginning with “tor” has something to do with twisting — such as torque, which refers to the twisting force exerted by an engine. Torsion itself simply means twisting, and in a vehicle, it refers to the kind that would happen if Godzilla grabbed it, front and rear, and twisted either end in opposite directions. The forces a vehicle encounters when cruising and turning are not quite as great, but they are a significant issue. A vehicle with high torsional rigidity resists these forces better than one with low torsional rigidity.

A little flex in a vehicle’s structure doesn’t hurt, but overall, you don’t want too much torsion in your vehicle’s body. Low rigidity in a vehicle results in vibrations and degrades handling performance. Good handling performance relies, in part, on suspension designs that optimize wheel/road contact under all conditions. Introduce too much torsion to a vehicle’s body, and the wheels are no longer where they are supposed to be relative to each other. In these cases, even well-engineered suspensions don’t stand a chance.

So there is such a thing as too much rigidity.

More:

Sometimes called chassis stiffness. It relates to how rigid the chassis is in twisting. Imagine a sport utility vehicle that needs to climb over rocks. Those without long suspension movements sometimes have lower torsional rigidity to allow the chassis to respond to uneven ground. A passenger car, on the other hand, should have high torsional rigidity in order to give the car a smooth ride, less vibration and better handling. Sports and performance cars are usually the stiffest in order to minimize any flex except for that offered by the springs and shocks to obtain consistent handling.

 

[Zafiro]

Porsche Carrera GT - 26,000Nm/degree

 

[Ultimate Car Guy]

I can't believe BMW has comparatively low rigidity, i thought they'd have amongst the highest, thats why their cars handle so well.

 

[Zafiro]

Saab 9-3 Sportcombi - 21,000 Nm/degree
Opel Astra - 12,000 Nm/degree
Bugatti EB110 - 19,000 Nm/degree
VW Passat (2006) - 32,400 Nm/degree
Land rover Freelander 2 - 28,000 Nm/degree
RR Phantom - 40,500 Nm/degree
Mazda RX8 - 30,000 Nm/degree
BMW X5 (2004) - 23,100 Nm/degree

 

[SDNR]

The Phantom's rigidity is very impressive. 40,500 Nm/degree makes it one of the most rigid cars made.

 

[Monster]

Re: Torsional Rigidity

I thought so too, can someone explain the metal characteristics?
.

Aluminium by itself is not stiffer than steel, you can have aluminium alloy with different elements to make it stiffer, steel is generally stiffer than aluminium. That is pretty much all i remember from 1st year uni material science.

I am impressed by the RX-8, it is lacking a B pillar but those Mazda engineers have managed to design a very stiff body.

 

[Zafiro]

Chevrolet Corvette C5 9,100 Nm/deg
Lamborghini Countach 2,600 Nm/deg
Aston Martin Vanquish 28.500 Nm/deg
Ford Focus 3d 19.600 Nm/deg
Ford Focus 5d 17.900 Nm/deg

 

[Sayyaaf]

Guys I can't remember if this is correct but Aluminium tend to "Break" if a force is applied to it after some point, where is Steel is more "Flexible" to applied forces.

 

[Mr. M]

The Phantom's rigidity is very impressive. 40,500 Nm/degree makes it one of the most rigid cars made.

Yeah.

Upon reviewing the list, the Passat's stiffness is impressive too: 32,000Nm/degree, making it one of the stiffest cars together with the Phaeton.

One interesting fact I read up is that Porsche 911 convertibles have iron beams that slide between the doors and the rest of the body after you have closed the doors, effectively increasing torsional rigidity while on the movie. It deactivates when you engage the open handle to open the door.

But as we can see from these numbers, torsional rigidity doesn't play a very big part in a car's performance if other factors don't support its benefits.

 

[Mr. M]

Guys I can't remember if this is correct but Aluminium tend to "Break" if a force is applied to it after some point, where is Steel is more "Flexible" to applied forces.

I have read about something similar too. That's why cars that are made with poor aluminium composites like Jaguars have warping problems.

 

[twsnelson]

Where can I get the original sources for the torsional rigidity for 4 wheel drive off road vehicle? any type also can because i wan use it as reference for my Uni' project.
TQ

 

[hoffmeister_fan]

^DAMN thats rigid..haha

That's what she said.



Sorry, I know it's a 4 year old post, but it had to be done. Otherwise it would have nagged at me all night and I wouldn't be able to sleep knowing that such an obvious retort was not said. Now I can sleep in peace tonight .


Regarding rigidity, I didn't know this thread existed till now. Alot of cools stuff on here.

 

[Sunny]

E39 5 - 24000Nm/deg
E60 5 - 24000Nm/deg
F10 5 - 37500Nm/deg
W212 E - 29920Nm/deg

Sources here -
BMW F10 5er vs Mercedes Benz W212 E-Klasse Body Rigidity

Some more figures from the torque book UGC linked -

Bentley Azure - 18000Nm/deg
Mercedes SL (R230) - 15800Nm/deg
Jaguar XK - 16000Nm/deg

E70 X5 - 28000Nm/deg
E30 M3 - 23000Nm/deg Source - BMW Z4M Still Under Consideration

 

[mayham85]

dear friends i want to ask a question? what is torsional rigidity ? Can someone explain it?