Torsional rigidity of the body or zhK / c is a value that characterizes the strength features of the automobile skeleton, its durability and safety. This value has a strong influence on the controllability of the car. That is why the world's famous supercars, equipped with carbon fiber and soft lightweight body panels, are distinguished by the highest values of this very parameter. Let's consider the indicators of LCD / c of well-known domestic models, compare them with the indicators of foreign cars.
Indicators of the Lada Kalina model
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The car skeleton of Kalina was designed taking into account the most important canons of industrial safety. Approximately twelve percent of the body elements on this domestic car are made of high-strength steel. More than half of the iron is covered with zinc. For comparison, for example, on the popular "top ten" only 33 percent of iron was galvanized.
As for the LC / c, Kalina's indicator is as much as twenty percent higher than that of the same “ten”. The PB of the Lada Kalina sedan, even without the use of pillows, has 3 out of 5 stars according to the Euro crash test system.
Despite the large amount of criticism against Kalina, designers and engineers of the domestic automobile plant regularly make improvements. In particular, if we take a closer look at Kalina of the second generation, we will see important points.
For example, what a successful exterior is worth - more solid, aggressive and, of course, attractive. All this was achieved with simple tricks: slightly raised the hood, added more chrome lining and improved the appearance of the optics.
Now, as for the management itself. On the former Kalina, it was worth turning the steering wheel to the right and left, as the car began to roll over, although it retained the straightness of movement. It is not known whether anyone dared to experiment with the steering wheel on bad roads, because it threatened almost with a "changeling".
The new Kalina will definitely not give such a reason, since in addition to increasing the value of ZhK / c, a clear steering adjustment was carried out. As a result, it has become easier to go around road bumps, bumps and pits.
Interesting. Sharp steering helped to make the following settings. The “short” rack technology mastered on foreign cars was used, and instead of four turns of the steering wheel, only three were left. And another change concerned more rigid fasteners.
One more fact is noteworthy. Previously, the fixation of the steering was carried out by means of rubber bushings. The technology is proven, but clearly outdated. And at AvtoVAZ they decided to try, however, only on the left rail support a more rigid method of fastening. This immediately paid off, the stiffness of the steering system increased by as much as 25 percent!
AvtoVAZ engineers did a good job adding a new rear suspension compression buffer as well. The part has advanced characteristics that reduce rolls by several times. Coupled with the increased rates of liquid / c, this gives a powerful effect, and more and more Kalina began to resemble Grant with her confident “taxiing” and smooth suspension operation.
Lada Priora
The next domestic model produced at the Volga Automobile Plant is the Lada Priora. Today it is produced in 4 body variations. Priora Coupe is also present in the line of models - it has not won, however, any other popularity among Russians.
An important parameter of the body of the Priora, again, is the value of zhK / c. It is noteworthy that for Priora this figure is 12,000 Nm / deg in the sedan version. For other variations, except for the coupe, it is one row lower.
Despite this, there are general indicators for all 3 models, implying body dimensions. So, the wheelbase, ground clearance and width are the same for all body types (except for the coupe). As for the length, we recall that the sedan indicators are 4350 mm, the hatchback ones are 4210 mm, and the universal ones are 4340 mm. The body height is also different: sedan - 1420 mm, hatchback - 1435 mm, and station wagon - 1508 mm.
Initially, the roof, hood and trunk were considered the weak areas of Priora bodies. It is for this reason that experts insist on the mandatory treatment by the owner of the car of all internal surfaces of problem areas with anticorrosive.
Priora body protection against corrosion is given for 6 years. In practice, this period is determined by: zinc coating of thresholds, bottoms and arches, as well as the use of low-alloy steel.
Indeed, practical experience has proven that the body of the Priora is incredibly resistant to corrosion. If problems begin, then bumpers fall into the risk group first of all, then bubbles form on the paintwork in the winter season, the paint peels off.
12,000 Nm / deg on the Priory sedan is not a big value. Even the VAZ-21106, not to mention foreign cars, this figure is higher. Thus, it would be good for Priora owners who prefer active driving to strengthen the car frame. In particular, reinforcement should include the installation of strut braces and the modernization of the STC on the axle at the rear.
Lada Granta
Grant's liftback is a 3-volume body, which implies a successful combination of a luggage cover with a rear window. It is noteworthy that in the era of the USSR, liftbacks as such did not exist. There was such a model - IZH-2125 Kombi, but it only embodied some liftback ideas. In fact, such a word was not legalized in the CAS, although there were such concepts as fastback, phaeton and even bregam.
Thus, the Lada Granta Liftback restores historical justice, because in addition to the new name, the car was produced just at the IAP, now referred to as the OAG.
Note. Today, the Izhevsk Automobile Plant is more of a branch of the Togliatti enterprise, which does not engage in its own developments.
Liftback is not just a word. So, this type of body looks good in terms of LCD performance. This figure has become twice as high as that of hatchbacks, although less than that of sedans due to design features.
In particular, the difference in design features between the liftback and the sedan lies primarily in the “rear cross member”. The liftback does not have this part at all, it is not provided for, and for sedans it passes behind the back of the rear sofa.
Note. In principle, the crossbar could be put on the liftback, but in this case all the convenience associated with loading into the trunk would disappear. The car would have lost half its practicality, which is unacceptable under any circumstances, even for the sake of the performance of the LCD.
Trying to somehow compensate for the loss in the housing complex, the engineers went to the following. They added amplifiers in some places, thus increasing the figure significantly, and only slightly falling short of the sedan's result.
In addition, due to the introduction of amplifiers, the liftback became 15 kg heavier, and this, in turn, had a negative effect on the torsion indicator.
Car body stiffness table
| car model | Rigidity, Nm/deg |
| Alfa Romeo 147 3d | 18800 |
| Alfa Romeo 147 5d | 16250 |
| Alfa Romeo 156 | 18800 |
| Alfa Romeo 159 | 31400 |
| Alfa Romeo 166 | 24400 |
| Alfa Romeo | 17650 |
| Aston Martin DB9 Convertible | 15500 |
| Aston Martin DB9 Coupe | 27000 |
| Aston Martin Vanquish | 28500 |
| Audi A2 | 11900 |
| Audi A8 D2 | 25000 |
| Audi A8 D3 | 36000 |
| Audi A8 D4 | 45000 |
| Audi R8 | 40000 |
| Audi TT Coupe mk1 | 19000 |
| Audi TT Roadster mk1 | 10000 |
| Audi TT Roadster mk2 | 22000 |
| Bentley Azure | 18000 |
| Bentley Continental Supersports | 24000 |
| Bentley Flying Spur mk2 | 36500 |
| BMW 7 series E65 | 31200 |
| BMW 7 series F01 | 37500 |
| BMW E34 | 17200 |
| BMW E36 Touring | 10900 |
| BMW E39 | 24000 |
| BMW E46 Convertible | 10500 |
| BMW E46 Coupe | 12500 |
| BMW E46 Sedan | 13000 |
| BMW E46 Wagon | 14000 |
| BMW E60 | 24000 |
| BMW E90 | 22500 |
| BMW F10 | 37500 |
| BMW F30 | 25000 |
| BMW X5 E53 | 23100 |
| BMW X5 E70 | 28000 |
| BMW Z3 mk1 | 5600 |
| BMW Z4 Coupé mk1 | 32000 |
| BMW Z4 Roadster mk1 | 14500 |
| BMW Z8 | 40000 |
| Bugatti EB110 | 19000 |
| Bugatti Veyron | 50000 |
| Chevrolet Corvette C5 | 9100 |
| Chrysler Crossfire | 20140 |
| Citroen Picasso mk1 | 17000 |
| Daewoo Lanos 3d 1997 | 10500 |
| Daewoo Nubira 1997 | 14500 |
| Dodge Durango mk1 | 6800 |
| Dodge Viper Coupe mk2 | 7600 |
| Ferrari 360 Spider | 8500 |
| Ferrari 575M Maranello | 14700 |
| Ferrari F50 | 34600 |
| Fiat Brava | 9100 |
| Fiat Bravo | 10600 |
| Fiat Punto 3d | 19700 |
| Fiat Tempra | 6700 |
| Ford Fiesta 3d 1995 | 6500 |
| Ford Focus 3d mk1 | 19600 |
| Ford Focus 5d mk1 | 17900 |
| Ford GT | 27100 |
| Ford GT40 MkI | 17000 |
| Ford Maverick 5d 1995 | 4400 |
| Ford Mustang 2003 | 16000 |
| Ford Mustang 2005 | 21000 |
| Ford Mustang Convertible (2003) | 4800 |
| Ford Mustang Convertible (2005) | 9500 |
| Jaguar XK mk2 | 16000 |
| Jaguar X-Type Estate | 16300 |
| Jaguar X-Type Sedan | 22000 |
| Koenigsegg Agera | 58000 |
| Koenigsegg Agera R | 65000 |
| Koenigsegg CC-8 | 28100 |
| Lamborghini Aventador | 35000 |
| Lamborghini Gallardo | 23000 |
| Lamborghini Murciélago | 20000 |
| Lancia Kappa Coupe | 27350 |
| Land Rover Freelander 2 | 28000 |
| Lexus LFA | 39130 |
| Lotus Elan | 7900 |
| Lotus Elise S2/Exige (2004) | 10500 |
| Lotus Esprit SE Turbo | 5850 |
| Maserati Quattroporte 2008 | 18000 |
| Mazda CX-5 | 27000 |
| Mazda CX-7 | 23700 |
| Mazda Rx-7FD | 15000 |
| Mazda Rx-8 | 30000 |
| McLaren F1 | 13500 |
| Mercedes SL R230 | 16400 |
| Mercedes SL R231 | 19400 |
| Mercedes SLS Roadster | 18000 |
| Mercedes E-Class W212 | 29920 |
| Mercedes S-Class W221 | 27500 |
| Mercedes S-Class W222 | 40500 |
| Mini (2003) | 24500 |
| Nissan Micra 1995 | 4000 |
| Nissan Prairie 4x4 5d 1995 | 7500 |
| Nissan Sunny 3d 1995 | 8200 |
| Opel Astra 3d 1998 | 10500 |
| Opel Astra 4d 1998 | 11900 |
| Opel Astra 5d 1998 | 11700 |
| Opel Combo 1999 | 18500 |
| Opel Corsa 3d 1995 | 6500 |
| Opel Corsa 3d 1999 | 8000 |
| Opel Omega 1999 | 13000 |
| Opel Vectra 4d 1999 | 8800 |
| Pagani Zonda C12 S | 26300 |
| Pagani Zonda F | 27000 |
| Pagani Zonda Roadster | 18000 |
| Peugeot 206CC | 8000 |
| Peugeot 407 | 22700 |
| Porsche 911 Carrera S 991 | 30400 |
| Porsche 911 Turbo 993 | 13500 |
| Porsche 911 Turbo 996 | 27000 |
| Porsche 911 Turbo 996 Convertible | 11600 |
| Porsche 911 Turbo 997 | 34000 |
| Porsche 959 | 12900 |
| Porsche Carrera GT | 26000 |
| Porsche Cayman 981 | 42000 |
| Porsche Panamera | 25000 |
| Range Rover mk3 | 32500 |
| Renault Sport Spider | 10000 |
| Renault Twingo 1995 | 14200 |
| Rolls-Royce Phantom | 40500 |
| Saab 9-3 Cabriolet mk2 | 11500 |
| Saab 9-3 Sedan mk2 | 22000 |
| Saab 9-3 Sportcombi mk2 | 21000 |
| Seat Leon 2005 | 23800 |
| Toyota Corolla 3d 1995 | 10500 |
| Toyota Prius 2001 | 22700 |
| Toyota Starlet 5d 1995 | 7600 |
| Volkswagen Fox 2007 | 17900 |
| Volvo S60 mk1 | 20000 |
| Volvo S80 mk1 | 18600 |
| VW Golf V GTI | 25000 |
| VW Passat B6 | 32400 |
| VW Phaeton | 37000 |
| VAZ-1111E Oka | 7000 |
| VAZ-21043 | 6300 |
| VAZ-2105 | 7300 |
| VAZ-2106 | 6500 |
| VAZ-2107 | 7200 |
| VAZ-21083 | 8200 |
| VAZ-21093 | 6800 |
| VAZ-21099 | 5500 |
| VAZ-2110 | 8000 |
| VAZ-21102 | 8400 |
| VAZ-21106 | 12200 |
| VAZ-21106 (racing) | 51800 |
| VAZ-21108 Premier | 10500 |
| VAZ-21109 Consul | 14300 |
| VAZ-2111 | 7400 |
| VAZ-2112 | 8100 |
| VAZ-2115 | 5500 |
| VAZ-2120 Hope | 10000 |
| VAZ-21213 Niva | 8900 |
| VAZ-2123 Chevy-Niva | 12000 |
| VAZ-2131 Niva | 7400 |
| GAZ-M20 Pobeda | 4600 |
| MZMA-400 Moskvich | 2500 |
Of course, the torsional rigidity of the body is one of the most important indicators of a modern car. Let's hope that over time, our engineers will come up with more efficient schemes and refine the design so that domestic cars occupied the top lines in the ranking of the best autocars in the world for this indicator.
Every athlete involved in motorsport (for pleasure or professionally) has a duty to improve the safety of the car. No salon car is designed for the loads that the body faces in the race. To prevent the driver from being seriously injured at high speeds in a collision, a safety cage is installed in the passenger compartment.
From the material you will learn about the features of this design, varieties and their differences. Read the technical documentation, and other useful information on the topic.
What is a safety cage
The safety cage is a structure consisting of steel pipes. It is mounted inside the vehicle, after which it is screwed or welded to the body at key points. The main task of the frame is to give additional rigidity.
The spatial safety cage prevents serious deformation of the body in case of a rollover or collision of the vehicle with other objects. The need to install the structure is dictated by the international regulations of the FIA sports association, as well as a number of other regulatory bodies.
Body rigidity
The rigidity of the body of modern cars is an important parameter on which its safety depends. The lower the rigidity of the body, the faster cracks and metal fatigue will begin to appear in loaded places.
On the other hand, when you get into a traffic accident, a body with a small margin of rigidity is deformed more. This increases the likelihood of a fatal outcome at the same speed compared to a car that has this figure an order of magnitude higher.
In addition, this parameter characterizes the overall strength of the vehicle, the degree of passive safety and durability. The body is the supporting structure of the entire vehicle, attachments, passengers and transported goods.
If the torsional rigidity is insufficient, when driving over bumps, the car starts to “play”. This will lead to incorrect operation of the suspension, its unpredictable behavior at high speed. Torsion should be reduced as much as possible.
The main parameter, based on which experts conduct testing, is the torsional rigidity of the body along the longitudinal axis. The task is to determine how much force must be applied to the body in order to cause deformation by 1 degree. Rigidity is measured in Nm/degree.
The most rigid are cars with a one-volume body layout, when the silhouette resembles the shape of a cube, such as minivans. Two and three-volume bodies have much less resistance. A large number of doors also reduces the rate. The lowest rigidity in cars with an open top.
Body Stiffness Table
| Model | Hardness (Nm/g) |
|---|---|
| Koenigsegg Agera R | 65000 |
| Koenigsegg Agera | 58000 |
| VAZ-21106 (racing) Yellow shark | 51800 |
| Bugatti Veyron | 50000 |
| Audi A8 D4 | 45000 |
| Porsche Cayman 981 | 42000 |
| Mercedes S-Class W222 | 40500 |
| Rolls-Royce Phantom | 40500 |
| Audi R8 | 40000 |
| Lexus LFA | 39130 |
| BMW 7 series F01 | 37500 |
| BMW F10 | 37500 |
| VW Phaeton | 37000 |
| Bentley Flying Spur mk2 | 36500 |
| Audi A8 D3 | 36000 |
| Lamborghini Aventador | 35000 |
| Ferrari F50 | 34600 |
| Porsche 911 Turbo 997 | 34000 |
| Range Rover mk3 | 32500 |
| VW Passat B6 | 32400 |
| BMW Z4 Coupé mk1 | 32000 |
| Alfa Romeo 159 | 31400 |
| BMW 7 series E65 | 31200 |
| Porsche 911 Carrera S 991 | 30400 |
| Mazda Rx-8 | 30000 |
| Mercedes E-Class W212 | 29920 |
| Aston Martin Vanquish | 28500 |
| Koenigsegg CC-8 | 28100 |
| BMW X5 E70 | 28000 |
| Land Rover Freelander 2 | 28000 |
| Mercedes S-Class W221 | 27500 |
| Lancia Kappa Coupe | 27350 |
| Ford GT | 27100 |
| Aston Martin DB9 Coupe | 27000 |
| Mazda CX-5 | 27000 |
| Pagani Zonda F | 27000 |
| Porsche 911 Turbo 996 | 27000 |
| Pagani Zonda C12 S | 26300 |
| Porsche Carrera GT | 26000 |
| Audi A8 D2 | 25000 |
| BMW F30 | 25000 |
| Porsche Panamera | 25000 |
| VW Golf V GTI | 25000 |
| Mini 2003 | 24500 |
| Alfa Romeo 166 | 24400 |
| Bentley Continental Supersports | 24000 |
| BMW E39 | 24000 |
| BMW E60 | 24000 |
| Seat Leon 2005 | 23800 |
| Mazda CX-7 | 23700 |
| BMW X5 E53 | 23100 |
| Lamborghini Gallardo | 23000 |
| Peugeot 407 | 22700 |
| Toyota Prius 2001 | 22700 |
| BMW E90 | 22500 |
| Audi TT Roadster mk2 | 22000 |
| Jaguar X-Type Sedan | 22000 |
| Saab 43533 Sedan mk2 | 22000 |
| Ford Mustang 2005 | 21000 |
| Saab 43533 Sportcombi mk2 | 21000 |
| Chrysler Crossfire | 20140 |
| Lamborghini Murciélago | 20000 |
| Volvo S60 mk1 | 20000 |
| Fiat Punto 3d | 19700 |
| Ford Focus 3d mk1 | 19600 |
| Mercedes SL R231 | 19400 |
| Audi TT Coupe mk1 | 19000 |
| Bugatti EB110 | 19000 |
| VAZ-2180 Lada Vesta | 19000 |
| Alfa Romeo 147 3d | 18800 |
| Alfa Romeo 156 | 18800 |
| Volvo S80 mk1 | 18600 |
| Opel Combo 1999 | 18500 |
| Bentley Azure | 18000 |
| Maserati Quattroporte 2008 | 18000 |
| Mercedes SLS Roadster | 18000 |
| Pagani Zonda Roadster | 18000 |
| Ford Focus 5d mk1 | 17900 |
| Volkswagen Fox 2007 | 17900 |
| Alfa Romeo | 17650 |
| BMW E34 | 17200 |
| Citroen Picasso mk1 | 17000 |
| Ford GT40 MkI | 17000 |
| Mercedes SL R230 | 16400 |
| Jaguar X-Type Estate | 16300 |
| Alfa Romeo 147 5d | 16250 |
| Ford Mustang 2003 | 16000 |
| Jaguar XK mk2 | 16000 |
| Aston Martin DB9 Convertible | 15500 |
| Mazda Rx-7FD | 15000 |
| Ferrari 575M Maranello | 14700 |
| BMW Z4 Roadster mk1 | 14500 |
| Daewoo Nubira 1997 | 14500 |
| VAZ-21109 Consul | 14300 |
| Renault Twingo 1995 | 14200 |
| BMW E46 Wagon | 14000 |
| McLaren F1 | 13500 |
| Porsche 911 Turbo 993 | 13500 |
| BMW E46 Sedan | 13000 |
| Opel Omega 1999 | 13000 |
| VAZ-2191 Lada Granta sedan | 13000 |
| Porsche 959 | 12900 |
| BMW E46 Coupe | 12500 |
| VAZ-21106 | 12200 |
| VAZ-2123 Chevy-Niva | 12000 |
| VAZ-2170 Lada Priora | 12000 |
| Audi A2 | 11900 |
| Opel Astra 4d 1998 | 11900 |
| Opel Astra 5d 1998 | 11700 |
| VAZ-2191 Lada Granta liftback | 11700 |
| Porsche 911 Turbo 996 Convertible | 11600 |
| Saab 43533 Cabriolet mk2 | 11500 |
| VAZ-1119 Lada Kalina hatchback | 11000 |
| BMW E36 Touring | 10900 |
| Fiat Bravo | 10600 |
| BMW E46 Convertible | 10500 |
| BMW Z8 | 10500 |
| Daewoo Lanos 3d 1997 | 10500 |
| Lotus Elise S2/Exige 2004 | 10500 |
| Opel Astra 3d 1998 | 10500 |
| Toyota Corolla 3d 1995 | 10500 |
| VAZ-21108 Premier | 10500 |
| Audi TT Roadster mk1 | 10000 |
| Renault Sport Spider | 10000 |
| VAZ-2120 Lada Nadezhda | 10000 |
| VAZ-1117 Lada Kalina wagon | 10000 |
| Ford Mustang Convertible 2005 | 9500 |
| Chevrolet Corvette C5 | 9100 |
| Fiat Brava | 9100 |
| VAZ-21213 Niva | 8900 |
| Opel Vectra 4d 1999 | 8800 |
| Ferrari 360 Spider | 8500 |
| VAZ-21102 | 8400 |
| Nissan Sunny 3d 1995 | 8200 |
| VAZ-21083 | 8200 |
| VAZ-2112 | 8100 |
| Opel Corsa 3d 1999 | 8000 |
| Peugeot 206CC | 8000 |
| VAZ-2110 | 8000 |
| Lotus Elan | 7900 |
| Dodge Viper Coupe mk2 | 7600 |
| Toyota Starlet 5d 1995 | 7600 |
| Nissan Prairie 4×4 5d 1995 | 7500 |
| VAZ-2111 | 7400 |
| VAZ-2131 Niva | 7400 |
| VAZ-2105 | 7300 |
| VAZ-2107 | 7200 |
| VAZ-1111E Oka | 7000 |
| Dodge Durango mk1 | 6800 |
| VAZ-21093 | 6800 |
| Fiat Tempra | 6700 |
| Ford Fiesta 3d 1995 | 6500 |
| Opel Corsa 3d 1995 | 6500 |
| VAZ-2106 | 6500 |
| VAZ-21043 | 6300 |
| Lotus Esprit SE Turbo | 5850 |
| BMW Z3 mk1 | 5600 |
| VAZ-21099 | 5500 |
| VAZ-2115 | 5500 |
| Ford Mustang Convertible 2003 | 4800 |
| GAZ-M20 Pobeda | 4600 |
| Ford Maverick 5d 1995 | 4400 |
| Nissan Micra 1995 | 4000 |
| MZMA-400 Moskvich | 2500 |
In everyday life, the car owner may also face the problem of rigidity. For example, when jacking up a car, or driving one wheel into an obstacle. Due to torsion, hinged body elements (doors, hood) begin to open poorly. The reason is just the lack of rigidity of the body.
Ways to increase stiffness
An increase in body rigidity is achieved not only by welding or screwing the frame, there are also less radical methods.
Mounted stiffeners
When a new car is released, the rigidity of its body is also calculated. The manufacturer lays down the necessary margin of rigidity, but if the vehicle is not intended for auto racing, then you should not expect miracles from it.
The easiest and most affordable way is to install stiffeners, popularly struts or "Already". They are divided into three types:
- Upper UZH. It is a link between the glasses, making their position fixed. The spacer distributes the load between the uprights, creating a single mechanism.
- Lower UZh. In the process of passing uneven sections of the road, it does not allow the spars to creep. Together, the bottom and top braces add a lot of stiffness, creating a frame.
- Rear UZh. Increases the rigidity of the rear glasses, distributing the load between them.
In addition, there are a lot of additional amplifiers for specific makes and models of cars: subframe, struts along the thresholds, on the wings (kerchiefs), frame under the bumper - bashbar (bash bar).
Installing spacers is not a way to prepare a car for racing, except at an amateur level.
Body reinforcement
This is already a more advanced way to increase rigidity, which is very laborious and costly in financial terms.
With integrated reinforcement, spot welds are additionally scalded. The attachment points of the units and especially loaded places of the body are reinforced with additional layers of metal. Particular attention is paid to the deformation zones provided by the manufacturer. Scarves and jumpers are welded into these places.
However, in order to prepare for participation in professional sports disciplines, the installation of a frame will be required.
Frame types
From a constructive point of view, there are two types of safety cage - bolted and welded. Let's consider each variety in more detail.
Bolted safety cage
Also called collapsible. Attaches to side pillars, sills and floor with bolts. At any time, the structure can be completely disassembled. As a rule, the bolt-on frame is popular among novice race car drivers, as well as owners who use the vehicle in combined mode - for everyday driving and participation in competitions.
When installing such a frame, you need to choose high-quality fasteners. If the bolts are bad, in the event of an accident, the structure can come unfastened and injure the driver.
Welded safety cage
In order to obtain body rigidity, regulated by the rules of automobile associations, with the help of a roll cage, you need to carefully study a number of applications.
Appendix J
It is an official document issued by the international automobile federation FIA (Fédération Internationale de l'Automobile). https://www.fia.com/
Promotion Rules security bodies by the frame method are prescribed in article 253. It indicates the technical parameters of each structural element used in the "cage". Read the translation of the article in PDF format.
Appendix 14
Developed by the Russian Automobile Federation. It is a regulation that establishes the use of automotive safety cages. Relevant for those who plan to compete in domestic championships.
Despite the overall integrity, the car body is a complex structure, welded together from dozens, and sometimes hundreds of elements. Add to this the loads acting on it from the suspension and units, causing internal stresses in the metal. Environmental factors also do not benefit the body and negatively affect its durability. Summarizing, we get that the "skeleton" of the car is not at all as fundamental as it might seem at first glance.
Why do manufacturers with their astronomical budgets do not provide sufficient body rigidity at the stage of designing and manufacturing a car, leaving a field for us, “tuningists”? First, they lay it down, but for ordinary, civilian driving. Secondly, during operation, it is lost, as well as obsolete “horses” running away from under the hood. Finally, design engineers cannot increase stiffness indefinitely, as they are constrained by dozens of other factors. For example, the use of high-strength steels increases the mass of the car and increases the cost of production, and individual elements, such as the front spars, for the sake of passive safety, must dampen the impact energy in a collision. Therefore, they must be made of soft alloys. In addition, there are layout restrictions that force elements to be curved, which in turn reduces their rigidity.
So, the cornerstone value, for the sake of increasing which everything is started, is the torsional rigidity of the body along the longitudinal axis of the car body. It is measured in Nm / degree and shows how much force must be applied to the body in order to bend it one degree. By modern standards, the normal indicator for cars with a monocoque body is 20,000 Nm / deg and above, while at the beginning of the century the figures were half as low. The maximum value of rigidity is possessed by the so-called "single-volume vehicles", whose power structure conditionally resembles a cube. It is worse with this case for three-volume cars, especially with a large number of doors, since the latter are not part of the power structure of the body. The biggest problem, therefore, is with open bodies: roadsters, convertibles and the like. That is why convertibles are often heavier than similar coupes - to compensate for the rigidity of the body due to the "went roof", their design is further enhanced.
Measuring the torsional stiffness of a body is a multi-stage and curious process. First of all, prototypes are tested in a virtual environment using programs that are not preinstalled on your Windows and MacOS. But the most interesting is the "live" test. In this case, the body is fixed on the frame of the measuring complex by the attachment points of the rear suspension. At this time, powerful hydraulic cylinders act on the attachment points of the front suspension, which create a “torsion” force in the vertical plane, but in different directions.
As we mentioned, during operation, the rigidity of the body inevitably decreases, and this will not bring good consequences in any case. A car with a “tired” body reacts more slowly to steering turns, its reactions are lax and ambiguous. In addition, "breathing" metal is more susceptible to deformation and stretching, as well as corrosion. When lifting on a jack, hanging diagonally or driving one of the wheels onto the curb, the doors may simply not open due to the resulting skew ... or not close. In short, the lack of rigidity must be combated. In what ways? Below is a list of them with the advantages and disadvantages of each.
Spacers
This variant of strengthening the body, perhaps, is more than the others "by ear". Hundreds of tuning companies today are ready to offer spacers for almost any car. Such parts are installed in regular places without significant modifications, and often they are supplied to a car that leaves the assembly line at the factory. But we are talking about tuning, so we will not consider “stock” options. Additional spacers are designed to tie together the most loaded, and therefore “walking” body elements, such as suspension strut cups, attachment points for levers and assemblies.
Parts designed to strengthen these nodes are made in accordance with the configuration of each car model separately - there are no universal parts here. The most popular product is the front strut brace, since it is the front of the car that experiences the maximum loads from the power unit, steering and overcoming road surface irregularities. The price of the issue is low and usually ranges from two to ten thousand rubles, while the “arrival” in handling from such a spacer is immediately noticeable, especially on a battered car. A complete set of spacers can "pull" a hundred thousand. However, remember that a “tired” body is primarily recommended for repair or replacement, and not for mounting amplifiers.
Pros:
- ease of installation and dismantling;
- low cost;
- some improvement in handling;
- a wide range of products for most vehicles.
Minuses:
- take up some space under the hood and in the cabin;
- slight increase in vehicle weight;
- for bodies with "tired" metal, they serve as a temporary solution.
Integrated amplification
It is possible to increase the rigidity of the body without installing additional elements - by strengthening the existing ones. In this case, “finishing” is done by the manufacturer. For example, regular spot welding, used in factories to simplify production, is reinforced with additional seams. A duplicating layer of metal is applied to the attachment points of levers and assemblies, which is scalded around the perimeter and in dots over the area. The places of bending of the regular metal are reinforced with jumpers and "kerchiefs", thus protecting themselves from vibrations.
Unlike spacers, this method of reinforcement is used in body repair or preparing cars for sports disciplines. It is also suitable if the car is old or there is no desire to resort to the first option. The cost of such reinforcement is determined not by details, as in the first case, but by the amount of work, since its implementation requires partial disassembly of the car, and high-quality welding requires qualifications from the master.
Pros:
- does not hide the place under the hood and in the cabin;
- increases the durability of individual elements and the body as a whole;
Minuses:
- high labor intensity;
- based on the first point, high cost if not performed independently;
- violation of the deformation zones provided by the manufacturer;
safety cage
The most radical way to increase body rigidity is a roll cage. Why not "stiffness frame"? The main purpose it serves is to preserve the living space in the car during collisions and coups. The interior of the car and the attachment points of the suspension are connected in this case by a "cage" of cold-rolled steel pipes. Such a frame also “breathes”, like the body, but this is necessary to absorb the energy of impacts and reduce the overload experienced by the pilot.
Scope - exclusively automobile competitions. Depending on the discipline, the requirements for safety cages also differ. So, in the world rally or “adult” ring series, the welded “cage” is so developed that without proper skill it will not be possible to get into the salon at all, while in the “club” disciplines the frame can consist of only a few pipes connected by bolts.
Installation of a safety cage implies local or complete strengthening of the body, described above, therefore, it is the most time-consuming and expensive operation, which, however, is not important when it comes to the pilot's life. This is the most time-consuming process, requiring high qualifications and specialized equipment (such as a pipe bender). It is not uncommon for a car to be modified to temporarily cut off the roof in order to weld the upper junctions of the frame. The installed product is accompanied by a certificate of conformity to a specific technical regulation - the so-called homologation. Of course, this design significantly increases the torsional rigidity of the body - as a rule, by 3-5 times.
Pros:
- preservation of living space during collisions;
- a significant improvement in handling and body integrity.
Minuses:
- high installation cost;
- the complexity of the work;
- increase in vehicle weight;
- unsuitability of the car for civilian use.
What is the result?
If the body of your car "weakened" during operation, it needs repair with the replacement of elements that have accumulated stress. This can be combined with the strengthening of individual elements in case the loads acting on them exceed those calculated by the manufacturer. In the case when there is a lack of information content and responsiveness in management, and the reason for this is the body, it is most logical to strengthen it with the help of spacers produced for an existing car. If the path of the car is competition, then you should take care not only about the rigidity of the body, but also about additional safety, therefore the frame is the only right decision. Let the body of your car be tough!
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| Body | ||||
| body type | - | - | - | - |
| Number of seats | - | - | - | - |
| Length | - | - | - | - |
| Width | - | - | - | - |
| Height | - | - | - | - |
| Wheelbase | - | - | - | - |
| Front track | - | - | - | - |
| Rear track | - | - | - | - |
| Curb weight | - | - | - | - |
| Ground clearance | - | - | - | - |
| Trunk volume maximum | - | - | - | - |
| Trunk volume minimum | - | - | - | - |
| Full mass | - | - | - | - |
| load capacity | - | - | - | - |
| Permitted weight of the road train | - | - | - | - | - | - | - | - |
| loading height | - | - | - | - |
| Cargo Compartment (Length x Width x Height) | - | - | - | - |
| The volume of the cargo compartment | - | - | - | - |
| Engine | ||||
| engine's type | - | - | - | - |
| Engine capacity | - | - | - | - |
| Engine power | - | - | - | - |
| Maximum power revolutions | - | - | - | - |
| Max Torque | - | - | - | - |
| intake type | - | - | - | - |
| Cylinder arrangement | - | - | - | - |
| Number of cylinders | - | - | - | - |
| Number of valves per cylinder | - | - | - | - |
| Supercharging type | - | - | - | - |
| Cylinder diameter | - | - | - | - |
| piston stroke | - | - | - | - |
| Turns maximum torque | - | - | - | - |
| The presence of an intercooler | - | - | - | - |
| Transmission and control | ||||
| Gearbox type | - | - | - | - |
| Number of gears | - | - | - | - |
| Drive unit | - | - | - | - |
| Turning diameter | - | - | - | - |
| Performance indicators | ||||
| Fuel grade | - | - | - | - |
| Max speed | - | - | - | - |
| Acceleration to 100 km/h | - | - | - | - |
| Fuel tank capacity | - | - | - | - |
| environmental standard | - | - | - | - |
| Fuel consumption in the city per 100 km | - | - | - | - |
| Highway fuel consumption per 100 km | - | - | - | - |
| Combined fuel consumption per 100 km | - | - | - | - |
| Power reserve | - | - | - | - |
| Suspension and brakes | ||||
| Front brakes | - | - | - | - |
| Rear brakes | - | - | - | - |
| Front suspension | - | - | - | - |
| Rear suspension | - | - | - | - |
| Steering | - | - | - | - |
| general information | - | - | - | - |
| Volume and mass | - | - | - | - |
| Safety | - | - | - | - |
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Vehicle comparison with proven and reliable features
Comparison of cars by parameters and characteristics on the Republican Automobile Portal "Avtobazaar.online" is designed specifically for lovers and owners of their own cars. Users until recently used Yandex as a similar service. But the service has not been available for several months now. Comparison of cars on Yandex auto does not exist as before. Therefore, we care about each client and provide a really convenient and reliable website that will help you compare the main technical characteristics of a car and make the right choice.
Benefits and benefits of functionality
Our car dealership in Donetsk and Lugansk regions provides an opportunity for every visitor to purchase a car at a profit. Thanks to a convenient and well-thought-out comparison system, it is possible to choose a car according to the requirements and financial capabilities. A well-thought-out interface and ease of use of the page allows you to select several models and brands, determine their advantages and disadvantages.Comparison of cars can be carried out according to the following main parameters:
It will allow you to choose the most optimal option, and invest in the available budget;
- Fuel efficiency (It will provide an opportunity to analyze fuel consumption in the city and beyond. A car with the best parameters will significantly save money and take care of the environment);
- Dimensions (The size of the car will be an important aspect when choosing. Comparing cars by parameters will help you choose a brand for a single person, a family man or a businessman);
- Power (Engine characteristics and transmission performance will help you choose a model with excellent speed and power parameters);
- Level of safety (The criterion will become especially important with regular use. Reliable protection during travel will be indicated for each brand).
In addition, the comparison table will contain many other criteria.
Comparison of cars by parameters and characteristics is a proven functionality on the Avtobazaar.online portal for viewing several cars at once. It is enough to choose the cars you like. The first thing to do is to decide on the brand, model and equipment of the car. To carry out the operation, you must select at least two models in the appropriate form below. The second is to perform a direct comparison. If you have any questions, we recommend that you contact our sales managers, who will clarify the details and offer the best purchase options.
From the point of view of reducing harmful emissions - of course, yes. The use of a turbine makes it possible to burn the combustible mixture more efficiently. This will be gladly confirmed by all car manufacturers, squeezed by the requirements of Euro-6.
However, the concept of "good ecology" includes not only harmful emissions, but also the reasonable consumption of the planet's resources. The internal combustion engine consumes the oxygen contained in the air, and the principle of turbocharging is based on the fact that more air passes through the combustion chambers than in an atmospheric engine.
It seems that the consumption of oxygen in the internal combustion engine (whose amount is steadily increasing) should be reduced until we have burned it all. But how? After all, no one canceled. Roughly speaking, about 3 kg of oxygen is burned with a liter of fuel, about 100 cubic meters of oxygen per 50-liter tank. Modern engines maneuver between different levels of mixture enrichment so as to get as little harmful rubbish as possible at the output, but in general this is the same range: from about 12: 1 to 14: 1 in operating modes (the ideal proportion for complete combustion of fuel is 14.7:1).
The supercharged motor, in theory, is sharpened to enrich the mixture to a greater extent than the aspirated one - that is, the proportion of air in the "supercharged" mixture is slightly lower. But the mixture, ceteris paribus, the supercharged engine will eat more. How to calculate what is worse for the environment - more harmful emissions or less oxygen?
Scientists say that the oxygen content in the atmosphere is gradually decreasing. A century and a half ago - 26%, now - about 21%. At 18%, a person will feel oxygen starvation. Actually, permanent residents of megacities have long been content with 19% and suffer from hypoxia, not always suspecting it. And at 17% ... it's better not to think about it yet.
The faster you go, the faster you get there
According to pure mathematics, such a statement is absolutely true - there is an unshakable formula for the dependence of distance and time on speed. But mathematics does not take into account forced stops to refuel and cleanse the body of toxins. And at long distances - say, from 1500 km or more - this is a fairly significant factor.
And we have here not some kind of France (950 km "in diameter" from north to south and from west to east) and 1500 km - quite an ordinary distance for Russian drivers. Many pass it "in one sitting." It is well known that the most economical driving mode on suburban highways is within 80-100 km / h in top gear. Faster - the motor will become noticeably more "eat".
Formula 1 could drive from Moscow to Sochi in five hours - in conditions of perfect asphalt, no traffic jams and, of course, ignoring traffic rules. But she would have to - with a 100-liter tank - stop at a gas station every 300 km. Travel time can increase by 15-20% because of this.
Formula 1 could drive from Moscow to Sochi in five hours - in conditions of perfect asphalt, no traffic jams and, of course, ignoring traffic rules. But she would have to - with a 100-liter tank - stop at a gas station every 300 km. Travel time can increase by 15-20% because of this.
Moreover, fuel consumption increases more rapidly than the speed of movement - partly due to the fact that air resistance is directly proportional to the square of speed. For some models, the difference in fuel consumption for speeds 90 and 120 is almost twofold. That is, if you keep the pedal to the floor all the time, there will be almost twice as many stops at gas stations. Each stop is at least ten minutes if there are no queues. And the total gain in time over a long distance, even if it takes place, is extremely small. It's worth it? Count yourself.
Body stiffness is a very important parameter
For designers, yes. For buyers, no. Because the vast majority of buyers do not even have a rough idea of the meaning and content of the parameter, expressed in Nm / deg. Although many intuitively understand the difference between torsional and bending stiffness. And in general, they guess that the higher the stiffness index, the better. But, say, 19,000 Nm/deg. - is the result of Lada Vesta a lot or a little? Is it good for a car of this class or bad?
Manufacturers willingly take advantage of the technical backwardness of consumers, reporting in the front descriptions of new products that the rigidity of the body has increased by 7, 15 or even 50 percent compared to the previous model. And they rarely report specific values, thus turning body stiffness into a purely marketing “lure”. Some factories do not consider it necessary to name any figures at all. Try, for example, to find data on body rigidity - one of the best-selling cars in Russia. From the "Repair and Operation Manual": "The body is a non-separable structure with sufficient rigidity ...".
Burning fuel indicator - urgently at the gas station!
If you are sure that your sensor and fuel gauge are not lying, then there is no particular hurry. Numerous experiments ZR in the field of fuel efficiency, when we drained the tanks of various models to a real void, showed that at the time the indicator was triggered, the power reserve was still fair. In specific numbers - from 40 to 80 km, sometimes even more than 100! That is, in terms of liters, manufacturers lay a reserve in the range of 10-15% of the volume of the fuel tank of the model.
The exception is some hybrids, which, as it turned out, categorically cannot stand when the fuel level in the tank is very low. It is better not to take risks with them and, at the signal of the indicator, immediately go to the nearest column.
Off-road needs all-wheel drive
Nothing like this. Four-wheel drive, of course, does not hurt, as well as high geometric cross-country performance. But, above all, you need tenacious tires - with wide grooves and faceted checkers. Many all-wheel drive crossovers off-road look very sour. And more than once in our "mud" and "snow" tests, the authors exclaimed - he would have tires "toothy"!
A tread with a frankly parquet pattern, ideal for asphalt, will be uncomfortable even on a rain-moistened even primer. And you will fall into a rut not at all because the car does not have all-wheel drive - it simply will not be able to catch on to the road at some point.
Four-wheel drive is certainly preferable to front or rear when you are already stuck and the car needs to be pulled out somehow. And to go - in most cases, one leading axle is enough.
Two sides of the coin
Almost any statement, and not only in the automotive world, is ambiguous and has a “back part”. If the seller in the cabin presses on “the largest trunk in the class”, “high diesel efficiency” or “outstanding off-road performance”, you, of course, listen to him culturally, but it is better to draw conclusions later, on common thought. A large trunk is often compensated by a cramped interior, the efficiency of a diesel engine negates its price relative to “gasoline”, and off-road qualities are generally unnecessary in an urban lifestyle.
All this is to ensure that we are not deceived - even from good intentions, when they want to give some recommendations. And so that we do not deceive ourselves.
Obvious non-obvious: controversial judgments about the car
