The list: Torsional Rigidity

[Mr. Mercedes]

Here's the Audi USA press release when the A8 won the Euro Car Body Award 2010!

The stiffness/weight ratio increased 20%, but the weight decreased about 30 kg. Thus we have:

D4 stiffness = D3 stiffness times 1.2 times 231 kg divided by 261 kg. If this data and calculation are correct (Please check ) this results in an excellent 38,200 Nm/degree torsional stiffness?

This luxury-class model manufactured in Neckarsulm dazzles thanks in large part to its stiffness/weight ratio: the relationship between torsional rigidity and the body’s weight. At a weight of just 231 kilograms (509.27 lbs), the aluminum body is about 40 percent lighter than a comparable version made of steel. In addition, it weighs nearly 30 kilograms (66.14 lbs) less than its predecessor; at the same time, its stiffness/weight ratio has increased by 20 percent.

As always, the man with all the information!

 

[Smithee]

As always, the man with all the information!

Mr Mercedes, in light of Wolfgang's new post I can certainly see why you were being sceptical about Audi.

Firstly neither of the press releases listed a rigidity number both only talked about the increase in % terms. On 01/12/09 the Audi of America press release stated the rigidity increased by 25%, 11 months later in the Euro Car Body press release dated 18/11/2010 it states that the rigidity increased by 20%.

So it went from 25% to 20%. It was losing rigidity as the time went on. Losing rigidity as time goes on could be a natural phenomenon that afflicts Audi A8 and its drivers.

 

[Mr. Mercedes]

LMAO!

I'm always skeptical when a figure is not stated in real terms and rather as percentage increases. Not that it should make a difference.

 

[astle]

I couldn't find such a list on the net, so I thought everyone could contribute here and make a list.

List updating when a member find new numbers:

Alfa 159 - 31.400Nm/degree
Aston Martin DB9 Coupe 27,000 Nm/deg
Aston Martin DB9 Convertible 15,500 Nm/deg
Aston Martin Vanquish 28,500 Nm/deg
Audi TT Coupe 19,000 Nm/deg
Bugatti EB110 - 19,000 Nm/degree
BMW E36 Touring 10,900 Nm/deg
BMW E36 Z3 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) 12,500 Nm/deg
BMW E46 Convertible 10,500 Nm/deg
BMW X5 (2004) - 23,100 Nm/degree
BMW E90: 22,500 Nm/deg
BMW Z4 Coupe, 32,000Nm/degree
BMW Z4 Roadster: 14,500 Nm/deg
Bugatti Veyron - 60,000 Nm/degree
Chrysler Crossfire 20,140 Nm/deg
Chrysler Durango 6,800 Nm/deg
Chevrolet Corvette C5 9,100 Nm/deg
Dodge Viper Coupe 7,600 Nm/deg
Ferrari 360 Spider 8,500 Nm/deg
Ford GT: 27,100 Nm/deg
Ford GT40 MkI 17,000 Nm/deg
Ford Mustang 2003 16,000 Nm/deg
Ford Mustang 2005 21,000 Nm/deg
Ford Mustang Convertible (2003) 4,800 Nm/deg
Ford Mustang Convertible (2005) 9,500 Nm/deg
Jaguar X-Type Sedan 22,000 Nm/deg
Jaguar X-Type Estate 16,319 Nm/deg
Koenigsegg - 28.100 Nm/degree
Lambo Murcielago 20,000 Nm/deg
Lotus Elan 7,900 Nm/deg
Lotus Elan GRP body 8,900 Nm/deg
Lotus Elise 10,000 Nm/deg
Lotus Elise 111s 11,000 Nm/deg
Lotus Esprit SE Turbo 5,850 Nm/deg
Maserati QP - 18.000 nm/degree
McLaren F1 13,500 Nm/deg
Mercedes SL - With top down 17,000 Nm/deg, with top up 21,000 Nm/deg
Mini (2003) 24,500 Nm/deg
Pagani Zonda C12 S 26,300 Nm/deg
Pagani Zonda F - 27,000 Nm/degree
Porsche 911 Turbo (2000) 13,500 Nm/deg
Porsche 959 12,900 Nm/deg
Porsche Carrera GT - 26,000Nm/degree
Rolls-Royce Phantom - 40,500 Nm/degree
Volvo S60 20,000 Nm/deg
Audi A2: 11,900 Nm/deg
Audi A8: 25,000 Nm/deg
Audi TT: 10,000 Nm/deg (22Hz)
Golf V GTI: 25,000 Nm/deg
Chevrolet Cobalt: 28 Hz
Ferrari 360: 1,474 kgm/degree (bending: 1,032 kg/mm)
Ferrari 355: 1,024 kgm/degree (bending: 727 kg/mm)
Ferrari 430: supposedly 20% higher than 360
Renault Sport Spider: 10,000 Nm/degree
Volvo S80: 18,600 Nm/deg
Koenigsegg CC-8: 28,100 Nm/deg
Porsche 911 Turbo 996: 27,000 Nm/deg
Porsche 911 Turbo 996 Convertible: 11,600 Nm/deg
Porsche 911 Carrera Type 997: 33,000 Nm/deg
Lotus Elise S2 Exige (2004): 10,500 Nm/deg
Volkswagen Fox: 17,941 Nm/deg
VW Phaeton - 37,000 Nm/degree
VW Passat (2006) - 32,400 Nm/degree
Ferrari F50: 34,600 Nm/deg
Lambo Gallardo: 23000 Nm/deg
Mazda Rx-8: 30,000 Nm/deg
Mazda Rx-7: ~15,000 Nm/deg
Mazda RX8 - 30,000 Nm/degree
Saab 9-3 Sportcombi - 21,000 Nm/degree
Opel Astra - 12,000 Nm/degree
Land rover Freelander 2 - 28,000 Nm/degree
Lamborghini Countach 2,600 Nm/deg
Ford Focus 3d 19.600 Nm/deg
Ford Focus 5d 17.900 Nm/deg
Koenigsegg Agera R 2013 65,000 Nm/degree

As far as I know, the Koenigsegg Agera R has the best torsional rigidity, with a value of 65,000 Nm/degree. The chassis(Monocoque) is full carbon fibre and weighs only 70kg!!!
Source:Agera R - Koenigsegg

 

[Human]

Great opportunity to speak my mind. Saw "How it's made" Audi R8. As they showcased the chassis (ASF) manufacturing, the first thing that came to my mind is the T.R. of the R8. Googled it fast, then and there = 40 000 Nm/Deg. @Betty Swollocks stiff chassis under your bottom, mate!

But let's face it, the Veyron @ 60 000 Nm/Deg could only be beaten by the M1 Abrams tank

 

[Monster]

As far as I know, the Koenigsegg Agera R has the best torsional rigidity, with a value of 65,000 Nm/degree. The chassis(Monocoque) is full carbon fibre and weighs only 70kg!!!

That is very impressive considering the Koenigsegg is designed with a removable top.

 

[Sunny]

That is very impressive considering the Koenigsegg is designed with a removable top.

I think single piece CF tubs suffer very little from the lack of a roof. Probably a function of both being a single piece and rigid nature of cured CF. For that matter, if someone made a tub from a single piece of metal by stamping it, it probably would not suffer too much from the lack of a welded on roof. It is the typical chassis that is made my welding multiple pieces together that suffers a lot by the lack of a roof.

ps. all just speculation on my part, have no real knowledge to back any of it.

 

[Gianclaudio]

I think single piece CF tubs suffer very little from the lack of a roof. Probably a function of both being a single piece and rigid nature of cured CF. For that matter, if someone made a tub from a single piece of metal by stamping it, it probably would not suffer too much from the lack of a welded on roof. It is the typical chassis that is made my welding multiple pieces together that suffers a lot by the lack of a roof.

ps. all just speculation on my part, have no real knowledge to back any of it.

Actually, the weldings on most cases are harder and more rigid than the steel that are joined together, but what I'm not sure if how the car structure works as one unit, as perhaps many panels are just point/spot welded and not continuosly, so there you have a point where it can lose rigidity. May be @Giannis who is a structural engineer can enlighten us.

 

[mini_cooper4]

Actually, the weldings on most cases are harder and more rigid than the steel that are joined together, but what I'm not sure if how the car structure works as one unit, as perhaps many panels are just point/spot welded and not continuosly, so there you have a point where it can lose rigidity. May be @Giannis who is a structural engineer can enlighten us.

Spot on!

 

[Giannis]

Actually, the weldings on most cases are harder and more rigid than the steel that are joined together, but what I'm not sure if how the car structure works as one unit, as perhaps many panels are just point/spot welded and not continuosly, so there you have a point where it can lose rigidity. May be @Giannis who is a structural engineer can enlighten us.

Rigidity of a certain member is typically measured by the Young's modulus (E) times the moment of inertia (I) of the cross-section. So, it's EI.

Something without a roof, has less moment of inertia compared to something with a roof (*). But having a very high modulus of elasticity, could make up for that. CFRP has a slightly higher E than steel (at least in the types used for structural applications).

(*) Imagine you have to balance some heavy weight over your head. Would it be easier if you were standing on only one foot, or both and spread a bit? Obviously the latter. Imagine that the CF tube is you, and its roof is your second leg. It's a bit more complex than that, but the principles are the same.

As far as welds are concerned, it's only one aspect of the whole rigidity issue. It's 2.25am here now, so I won't go into many details now, but until tomorrow, take a look at this post: Porsche 918 Spyder Concept

 

[Sunny]

Cayman 42k nm/deg
991 32k nm/degree
Mustang GT350 27k nm/ deg

 

[martinbo]

That Cayman's got some impressive structurally stiff members.

 

[Sayyaaf]

That Cayman's got some impressive structurally stiff members.

clever if I understood you

I am surprised that Porsche actually made the cayman stiffer than 991. too bad I don't live in the US or that BGB 3.8 conversion sounds soo right than ever.

 

[Gianclaudio]

Between"stiff members" and Andrea's "cock fight" we had quite a...mm...phallic day, yesterday.

Sorry for the off topic, and for being such a dick

 

[Anil]

I couldn't find such a list on the net, so I thought everyone could contribute here and make a list.

List updating when a member find new numbers:

Alfa 159 - 31.400Nm/degree
Aston Martin DB9 Coupe 27,000 Nm/deg
Aston Martin DB9 Convertible 15,500 Nm/deg
Aston Martin Vanquish 28,500 Nm/deg
Audi TT Coupe 19,000 Nm/deg
Bugatti EB110 - 19,000 Nm/degree
BMW E36 Touring 10,900 Nm/deg
BMW E36 Z3 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) 12,500 Nm/deg
BMW E46 Convertible 10,500 Nm/deg
BMW X5 (2004) - 23,100 Nm/degree
BMW E90: 22,500 Nm/deg
BMW Z4 Coupe, 32,000Nm/degree
BMW Z4 Roadster: 14,500 Nm/deg
Bugatti Veyron - 60,000 Nm/degree
Chrysler Crossfire 20,140 Nm/deg
Chrysler Durango 6,800 Nm/deg
Chevrolet Corvette C5 9,100 Nm/deg
Dodge Viper Coupe 7,600 Nm/deg
Ferrari 360 Spider 8,500 Nm/deg
Ford GT: 27,100 Nm/deg
Ford GT40 MkI 17,000 Nm/deg
Ford Mustang 2003 16,000 Nm/deg
Ford Mustang 2005 21,000 Nm/deg
Ford Mustang Convertible (2003) 4,800 Nm/deg
Ford Mustang Convertible (2005) 9,500 Nm/deg
Jaguar X-Type Sedan 22,000 Nm/deg
Jaguar X-Type Estate 16,319 Nm/deg
Koenigsegg - 28.100 Nm/degree
Lambo Murcielago 20,000 Nm/deg
Lotus Elan 7,900 Nm/deg
Lotus Elan GRP body 8,900 Nm/deg
Lotus Elise 10,000 Nm/deg
Lotus Elise 111s 11,000 Nm/deg
Lotus Esprit SE Turbo 5,850 Nm/deg
Maserati QP - 18.000 nm/degree
McLaren F1 13,500 Nm/deg
Mercedes SL - With top down 17,000 Nm/deg, with top up 21,000 Nm/deg
Mini (2003) 24,500 Nm/deg
Pagani Zonda C12 S 26,300 Nm/deg
Pagani Zonda F - 27,000 Nm/degree
Porsche 911 Turbo (2000) 13,500 Nm/deg
Porsche 959 12,900 Nm/deg
Porsche Carrera GT - 26,000Nm/degree
Rolls-Royce Phantom - 40,500 Nm/degree
Volvo S60 20,000 Nm/deg
Audi A2: 11,900 Nm/deg
Audi A8: 25,000 Nm/deg
Audi TT: 10,000 Nm/deg (22Hz)
Golf V GTI: 25,000 Nm/deg
Chevrolet Cobalt: 28 Hz
Ferrari 360: 1,474 kgm/degree (bending: 1,032 kg/mm)
Ferrari 355: 1,024 kgm/degree (bending: 727 kg/mm)
Ferrari 430: supposedly 20% higher than 360
Renault Sport Spider: 10,000 Nm/degree
Volvo S80: 18,600 Nm/deg
Koenigsegg CC-8: 28,100 Nm/deg
Porsche 911 Turbo 996: 27,000 Nm/deg
Porsche 911 Turbo 996 Convertible: 11,600 Nm/deg
Porsche 911 Carrera Type 997: 33,000 Nm/deg
Lotus Elise S2 Exige (2004): 10,500 Nm/deg
Volkswagen Fox: 17,941 Nm/deg
VW Phaeton - 37,000 Nm/degree
VW Passat (2006) - 32,400 Nm/degree
Ferrari F50: 34,600 Nm/deg
Lambo Gallardo: 23000 Nm/deg
Mazda Rx-8: 30,000 Nm/deg
Mazda Rx-7: ~15,000 Nm/deg
Mazda RX8 - 30,000 Nm/degree
Saab 9-3 Sportcombi - 21,000 Nm/degree
Opel Astra - 12,000 Nm/degree
Land rover Freelander 2 - 28,000 Nm/degree
Lamborghini Countach 2,600 Nm/deg
Ford Focus 3d 19.600 Nm/deg
Ford Focus 5d 17.900 Nm/deg

Hi Mr. M..
I just want to know these values are for BIW or for complete vehicle..???

Regards,

Anil

 

[JCH]

Excellence Magazine, September 2015, cites Porsche Cayman body shell torsional stiffness at 41,900 Nm/degree and claims it to be "the highest of any non-carbon-fiber tub production car" p61

(Glad to join the forum) JCH

I should add that's for the 981 version.