In our garage you can easily purchase tires of any profile, diameter and brand such as: Yokohama, Pirelli, Michelin, Continental, Kumho, Hankook, Nitto, Bridgestone, Goodyear and others.

Influence of wheel weights on handling, dynamics and other car parameters

Handling

If you hit an obstacle on the road, then the maximum impact force is not on the body, but on the wheel. Only then, through the snubber, the residual force reaches the body, and the wheel returns to its original state. Practice shows that with a decrease in the unsprung mass of a car, the impact force on the body decreases, and maneuvering becomes smoother and more comfortable. But do not abuse the weight reduction: if the unsprung weight is too low compared to the body weight, then it will take more time for the wheel to return to its original position. When driving in ideal weather, this will not affect safety, but on wet or slippery asphalt the likelihood of skidding will increase significantly.

Dynamic characteristics

Any engine is capable of producing only a certain amount of energy at a time. The heavier the wheels of the car are, the more power will be spent to spin them, which means that there will be a minimum amount of free energy for fast acceleration. If we take specific statistics, then reducing the mass of the wheels by one kilogram increases the power of the car by about 1%. Many car owners, knowing this, and also that forged wheels are lighter than cast ones, choose them to increase the performance of the car and reduce the acceleration time.

Smooth running

Calculations show that reducing the weight of each wheel by at least one kilogram is equivalent to reducing the weight in the cabin by 40 kilograms. In practice, you can give the following example: if you reduce the weight of each wheel by four kilograms (this is not difficult to do, given in one forged disc weight), then the ride will be the same as if you had four passengers in the cabin. Overclocking characteristics will remain at the same level.

Everyone knows the answer to the question «Which wheels are lighter, forged or cast?». For example, one original 20-inch alloy wheel for the Range Rover weighs about 25 kilograms. A forged analogue with a maximum static load for the same car — about 13 kilograms. Each wheel is approximately for 12 kg lighter. As a result, forged wheels reduce the unsprung weight by almost half a tonne, while improved ride comfort is achieved without sacrificing dynamics and acceleration characteristics.

Brief weight comparison of the main wheel types

• Steel discs made using stamping technology are the heaviest and most losing option. Many car owners prefer to replace such wheels with lighter ones immediately after buying a car. The only advantage of this category is its reasonable price.
• Aluminum alloy wheels provide a weight saving of approximately 20% compared to steel counterparts. In addition, they have a beneficial effect on the cooling of the brake system and are easy to process, which simplifies repairs and allows for unique design solutions for custom production.

• Forged wheels keep weight to a minimum. A special technology for the production of forged discs (hot stamping method) allows to reduce weight for 20–50% in comparison with analogs made of aluminum and steel, respectively. And due to the unsurpassed plasticity (with a strong impact, the disc does not burst, but only slightly deforms), reliability increases. Even though forged wheels are more expensive than their cast or steel counterparts, the increased dynamic performance, improved braking performance and maximum safety justify all the costs.

Often, the painted element is not dismantled from the car body, so as not to violate the factory integrity. Therefore, it is important to cover areas that will not be painted and to treat the surface to be painted with a degreaser. After that, you can proceed directly to painting the car parts.

Once the freshly painted car element is dry, it can be polished to give it a shine.

Full car painting

If the car has damage on 6 or more body panels or you want to radically refresh the look of your car, it is worth considering the second option, namely, full painting of the car.

The process of painting a car in this case is almost the same as painting individual parts. Differences between them is accordingly more costly both in time and in terms of money.

Paint selection

An important part of painting a car is choosing the right enamel. On this issue, the opinions of experts are divided: someone considers the only correct option to trust the vigilance of a specialist, whose eye can determine the required shade; others rely entirely on technology and computer programs that can recognize the exact color and tell you the color code so that you can accurately acquire the paint you want.

We leave this solution to specialists who have proven themselves in this market and use only high-quality car enamels, varnishes and hardeners Duxone, Mobihel, Roberlo, Standox, 4CR. All paintwork is carried out only in a spray booth. There the air undergoes mandatory filtration to obtain the desired result of the first time.

Where to start sprung repairs?

The most important thing, of course, is to understand what exactly is out of order and what is the cause of the malfunction; this requires diagnostics. Although experienced motorists, as a rule, do not delay the diagnostics of the chassis and carry out it during maintenance for prevention, this will help prevent unexpected surprises on the road and eliminate problems in a timely manner.

 Also, before making the camber and toe, the auto mechanic must make a running diagnostics, and until the defects are eliminated, the camber and toe will not be performed.

 Diagnostics is subdivided into «Computer», which is used only for vehicles with electronic sprung systems. “Manual Diagnostics” is the old proven old way, where you can see everything with your own eyes, and “Vibrator”, which creates for the sprung —  road conditions very similar to real conditions.

Diagnostics of the front and rear sprung of the car is performed.

 As a rule, the front sprung is repaired more often, this is due to the greater load on the units in the front of the car, plus the main control units are located in front part.

 After a complete diagnostics, the priority work is determined, and recommendations for spare parts are given. It is better to replace shock absorbers and levers with new ones than to repair old ones; when replacing, be aware that they change in pairs on the same axis, as well as brake discs and pads.

 Sprung levers fail a little less often (if you do not drive often at speedhumps), but it is recommended to change them even with the slightest deformation, because this leads to a change in camber and toe and abrasion of rubber, change levers in pairs. Rubber parts in the sprung, such as (rod bushings, boot, cover), are replaced with new ones even with minor damage or deformation. Even less often, the air sprung fails with proper maintenance of the system, regular service, but replacing the air struts and the valve block will cost a pretty penny.

 Different brands of cars have their own characteristics, so it makes sense to carry out diagnostics and repair of the chassis in proven car services with good specialists and high-quality equipment.

Causes of noise while driving or knocking on the sprung

• loosening of the sprung attachment due to heavy wear of the cushions on eyelets snubber and bushings
• overloading the rear of the vehicle
• Failure of snubbers
• wear of bushings located on the sprung arms
• Damage or deformation of the spring
• Breakage of the compression stroke buffer

The reasons for the appearance of deviations of the car from the trajectory while driving:

• Failure of one of the sprung springs or its deformation
• Displacement of the rear axle due to heavy wear of the bushings, which are located on the sprung arms
• Deformation of the sprung arms

The main causes of air sprung breakdown

Air sprung components are generally strong and reliable. But over time, they can become unusable, and the entire system stops to function.

The most common problems that arise are:

• Air bellows fail;
• The compressor breaks down;
• The air sprung chamber is bursting;
• The front air struts are depressurized;
• The stiffening valves of the pneumatic supports are damaged.

Ordinary car owners are unlikely to be able to identify a breakdown by the problems listed above. Therefore, we will tell you about the more obvious symptoms of a breakdown, so that you can understand in time what is happening to your car and contact us for an air sprung repair at Hammerhead Garage.

But there is a third type that has become popular on motor vehicles and Japanese cars — a variator. Experiments with variators were carried out back in the 50s by DAF company, and a little later by Volvo, but Japanese automakers, primarily Subaru and Nissan, showed massive interest.

The variator does not have gears at all. The change in gear ratios occurs continuously and constantly, regardless of whether the car is slowing down or accelerating. The main advantage of such boxes is comfort when moving around the city. The absence of steps gives a smooth ride, and when driving in heavy traffic, the gearbox does not «rush» between the first and second gears, which reduces wear on the gearbox and engine parts. In addition, fuel consumption is reduced: the engine does not need to spin up to high engine speeds in order to shift up.

In what cases is transmission repair necessary?

The most critical sign of a transmission malfunction is obstructed movement, or the car simply cannot move. Also, signs of a transmission breakdown may be:

• Arbitrary switching off the transmission;

When changing gears, you need to make a lot of effort;

Extraneous vibrations, grinding, noises occur;

Transmission fluid leaks or discoloration.

Causes of transmission breakdown

1. During operation, the fluid level in the transmission may drop as a result of leakage through the connections. In case of untimely topping up of fluid, a transmission breakdown may occur.
2. Incorrect car operation at low temperatures. For example, the transmission is exposed to significant loads without warming up the car, with thickened lubricant.
3. Incorrect vehicle operation — sharp acceleration and braking, towing heavy trailers, prolonged slipping, etc.

The main elements of the transmission

The transmission is a combination of several mechanisms that represent one single system:

• Gearbox;
• transfer case and power take-off;
• clutch;
• cardan and main gear;
• differential;
• hinges;
• mechatronic;
• sprung.

Over time, these elements can wear out, metal in places of increased stress can deform. Accordingly, if they are faulty, then an urgent repair of the car’s transmission will be required.

Why you should contact professionals

Professional service centers offer transmission maintenance and repair services. These events are complex and responsible, so they should be trusted exclusively by professionals.

Specialists will perform high-quality and prompt diagnostics and repair of transmissions of various brands. Among the advantages of contacting professionals is the availability of special knowledge, specialized expensive equipment and work experience.

For example, by contacting Hammerhead Auto Specialists, you can use services for:

• Replacement of the clutch;
• Gearbox repair;
• Replacement of crosspieces on cardan shafts;
• Replacement of working and master clutch cylinders;
• Oil change in automatic transmission, manual transmission;
• Replacement of drives and anthers of CV joints;
• Replacement of the valve block.

Transmission repair includes a number of stages:

• Diagnostics of the transmission condition;
• Removal of the checkpoint;
• Transmission repair, including: check point disassembly and troubleshooting, check point repair and assembly, check valve blocks;
• Installation of the checkpoint;
• Re-diagnostics of transmission operation.

Caring for the transmission is one of the prerequisites for the safe and long-term operation of the car. Service is recommended to be carried out in professional service centers and at intervals of 60,000-80,000 km, depending on the type of automatic transmission.

Car owners should regularly check the oil level and the performance of all vehicle systems, be attentive to any atypical behavior or changes in the engine state.

It is recommended to undergo engine diagnostics in the presence of one or several points:

• Oil consumption has increased significantly;

• The traction performance of the motor has decreased;

• Carbon deposits appeared on plugs;

• During engine operation, knocks and other extraneous sounds are heard;

• Oil leakage is observed;

• The exhaust of an atypical color appeared;

• The «Check Engine» indicator lights up.

What is engine repair?

Engine repairs can range from minor to major. It all depends on the degree of wear of parts, the type of parts, the timeliness of detecting breakdowns, etc. The price of car engine repair depends on the amount of work required to restore the unit.

In auto repair shops, ICE repairs have the following classification:

• Current, involving small work to eliminate faults and replace consumables;
• Medium, involving the removal or partial disassembly of the motor with the replacement of some parts;
• Major, involving the removal and disassembly of the engine, replacement or restoration of a large number of parts.
• After major repair, the engine is updated to the factory settings.

Stages of engine repair

Work aimed at restoring the engine is carried out in stages using specialized professional equipment. So, for the repair of gasoline engines, as well as diesel engines, the following are used:

• Autoscanners connected to the engine ECU;
• Stroboscopes to determine the correct setting of the ignition moment;
• Endoscopes — optical devices that allow you to determine the place of failure without disassembling the motor;
• Gas analyzers to determine the composition of the exhaust and other equipment.

At the diagnostic stage, the mechanical state of the engine, the tightness of all its components are determined, problems with the ignition, starter, ECU, generator, battery are identified, the quality of fuel combustion and the presence or absence of signs of engine overheating are checked.

After diagnostics, it becomes clear which unit is to be repaired, as well as the need for complete/partial disassembly of the engine, or the absence of such a need.

During the middle and overhaul of diesel engines and gasoline engines, the following works are performed:

• Removing the engine;
• Disassembly;
• Troubleshooting of units;
• Installation of new parts to replace the damaged ones;
• Cleaning or restoration of parts (if necessary);
• Assembly of the engine;
• Installation of the motor in place;
• Tuning and diagnostics of engine operation.

In cases where it is impossible or impractical to repair the internal combustion engine, the car owner may be offered to replace it, which can be carried out with a new or used engine. All performed work

 related to the restoration of the engine is guaranteed.

The radiator is designed to cool the heated coolant with an air stream. To increase heat transfer, the radiator has a special tubular device.

Along with the main radiator, an oil cooler and an exhaust gas recirculation cooler can be installed in the cooling system. An oil cooler serves to cool the oil in the lubrication system.

The exhaust gas recirculation cooler cools the exhaust gases, thereby reducing the combustion temperature of the air-fuel mixture and the formation of nitrogen oxides. The exhaust gas cooler is operated by an additional coolant circulation pump included in the cooling system.

The heat exchanger of the heater performs a function opposite to the radiator of the cooling system. The heat exchanger heats the air passing through it. For efficient operation, the heater heat exchanger is installed directly at the outlet of the heated coolant from the engine.

An expansion tank is installed to compensate changes in coolant volume due to temperature in the system. The system is usually filled with coolant through an expansion tank.

The circulation of the coolant in the system is provided by a centrifugal pump. In everyday life, a centrifugal pump is called a pump. A centrifugal pump can have a different drive:

gear, belt, etc. On some turbocharged engines, an additional coolant circulation pump is installed to cool the charge air and the turbocharger, which is connected by the engine control unit.

The thermostat is designed to regulate the amount of coolant passing through the radiator, which ensures the optimal temperature in the system. The thermostat is installed in the pipe between the radiator and the engine «cooling jacket».

Powerful engines are fitted with an electrically heated thermostat that provides two-stage coolant temperature control. For this, the thermostat has three operating positions: closed, partially open and fully open. When the engine is fully loaded, the electric heating thermostat opens it completely. In this case, the temperature of the coolant decreases to 90°C, the propensity of the engine to detonate decreases. In other cases, the coolant temperature is maintained within 105°C.

The radiator fan serves to increase the intensity of cooling the liquid in the radiator.

The fan can have a different drive:

• Mechanical (permanent connection with the engine crankshaft);

• Electric (controlled electric motor);

• Hydraulic (fluid coupling).

The most widespread is the electric fan drive, which provides ample opportunities for regulation.

Typical cooling system controls are a coolant temperature sensor, an electronic control unit and various actuators.

The coolant temperature sensor records the value of the monitored parameter and converts it into an electrical signal. To expand the functions of the cooling system (cooling the exhaust gases in the exhaust gas recirculation system, regulating the fan operation, etc.), an additional coolant temperature sensor is installed at the radiator outlet.

The signals from the sensor are received by the electronic control unit and converted into control actions on the actuators. As a rule, an engine control unit with the appropriate installed software is used.

The following actuators can be used in the control system: thermostat heater, auxiliary coolant pump relay, radiator fan control unit, engine cooling relay after stop.

How the cooling system works

The cooling system is operated by the engine management system. In modern engines, the operation algorithm is implemented on the basis of a mathematical model that takes into account various parameters (coolant temperature, oil temperature, outside temperature, etc.) and sets the optimal conditions for switching on and the operating time of structural elements.

The coolant in the system has forced circulation, which is provided by a centrifugal pump. The movement of fluid is carried out through the «cooling jacket» of the engine. This cools the engine and heats up the coolant. The direction of fluid movement in the «cooling jacket» can be longitudinal (from the first cylinder to the last) or transverse (from the exhaust manifold to the intake).

Depending on the temperature, the liquid circulates in a small or large circle. When the engine is started, the engine itself and the coolant in it are cold. To accelerate engine warm-up, the coolant moves in a small circle, bypassing the radiator. The thermostat is closed.

As the coolant heats up, the thermostat opens and the coolant moves in a large circle through the radiator. The heated liquid passes through the radiator, where it is cooled by the counterflow of air. If necessary, the liquid is cooled by an air flow from the fan.

After cooling, the liquid is returned to the «cooling jacket» of the engine. During engine operation, the coolant cycle is repeated many times.

On turbocharged vehicles, a dual-circuit cooling system can be used, in which one circuit is responsible for cooling the engine, the other for cooling the charge air.

Receiver replacement A/C repairing Dubai

At a certain temperature and a certain pressure, the cooled refrigerant condenses and turns into a liquid state. From the bottom, the refrigerant leaves the condenser and in a liquid state enters the receiver-drier, which consists of a receiver and a drier, installed on the condenser outlet pipe before the evaporator. The receiver-drier performs multiple functions, including storing the refrigerant, filtering it, and removing moisture. Sometimes, the filter is installed separately from the receiver. Moisture elimination is achieved by utilizing a special adsorbent with a limited service life.

Receiver 5 serves to smooth out fluctuations in the refrigerant flow.

Pic: Receiver-drier:

1 — Supply of refrigerant from the condenser; 2 — supply of refrigerant to the pressure reducing valve; 3 — drier; 4 — mesh filter; 5 – receiver

Drier 3 removes moisture that has entered the refrigerant circuit during installation or from the environment, as well as deposited wear products of compressor parts, dirt that got into the circuit during installation and other foreign impurities. The receiver-drier can be equipped with a sight glass to monitor the amount of refrigerant. In case of failure, the receiver-dryer is not repaired and must be replaced.

Pressure reducing valve replacement Dubai

After the dryer, the refrigerant flows to the pressure-reducing valve. The pressure-reducing valve in front of the evaporator lowers the pressure of the liquid refrigerant, which causes the evaporator to cool. The pressure-reducing valve is located at the boundary between the low and high-pressure sides of the refrigerant circuit. The valve regulates the flow of refrigerant to the evaporator, depending on the temperature of the refrigerant vapor at the outlet of the evaporator, therefore, the evaporator evaporates as much refrigerant as is necessary to maintain uniform «cold» in the evaporator.

If the temperature of the refrigerant leaving the evaporator rises, the refrigerant expands in thermostat 4, which is installed on the pressure reducing valve. In this case, the diaphragm 3 bends and the flow of refrigerant through the ball valve 2 to the evaporator increases.

Picture: Pressure reducing valve:

1 — Adjusting spring; 2 — ball valve; 3 — membrane; 4 — thermostat with sensor tube and refrigerant

If the temperature of the refrigerant leaving the evaporator decreases, then the amount of refrigerant in the thermostat decreases, and membrane 3 returns to the upper position. Refrigerant flow through the ball valve to the evaporator is reduced.

The thermostatic expansion valve operates under three forces:

• The 1st pressure in the sensor tube depends on the temperature of the hot refrigerant. This pressure acts as releasing force (PFu) on the diaphragm.
• 2nd evaporator pressure (PSa) acts on the diaphragm in the opposite direction
• 3rd control spring pressure (PFe) acts in the same direction as the evaporator pressure

The pressure relief valve sprays the chilled liquid into the evaporator.

Car A/C Evaporator repairing in Dubai

The evaporator speeds up the evaporation process. For this, it has a large surface area and acts as a heat exchanger between the refrigerant and the ambient air. The refrigerant that has passed through the pressure reducing valve, becoming volatile with low pressure, when passing in a foggy state through the aluminum evaporator pipeline, under the action of the airflow from the fan, evaporates into a gas at a temperature of -2°C and a pressure of 2.0 kg/cm2. In this case, the fins of the evaporator pipe become cold from the heat of vaporization, and the air inside the car becomes cool. In addition, the moisture contained in the air turns into the water from cooling and, together with the dust, flows through the drainpipe into the condensate pan and then onto the ground.

Car A/C Compressor replacement in Dubai

Piped refrigerant in its gaseous state goes to the compressor, which is driven by the motor shaft. The compressor increases the gas pressure to a high level. A clutch, powered by the crankshaft pulley through the drive belt, drives the compressor. When the clutch electromagnet doesn’t receive voltage, only the compressor clutch pulley rotates, while the compressor shaft remains still.On the other hand, when voltage activates the magnetic clutch, the clutch’s disc and sleeve move back and establish a connection with the pulley. The forces cause the pulley and disc to merge, resulting in the rotation of the compressor shaft.

Climate control compressors are of various types:

• piston chargers

• spiral chargers

• vane chargers

• swashplate axial piston blowers

• driven by an electric motor

Compressors with variable displacement axial piston types are the most widespread for air conditioning systems.

Picture: Scheme of a variable displacement axial piston compressor with a rotating swashplate:

1 — Runner; 2 — electromagnet; 3 — swashplate; 4 — piston; 5 — pump cylinder block cover; 6 — valves

A swashplate is connected to the drive shaft of the compressor, which during its rotation moves several (5…7) pistons. A cover with a valve system closes the body containing cylinders. The capacity of the compressor is determined by the desired cooling temperature. With these compressors, the inclination of the washer can change, which leads to a change in the piston stroke and, therefore, in the capacity. These types of compressors exert less impact on the engine operation when the clutch is engaged, which is particularly crucial for low-power engines. In addition, they provide greater stability at the set temperature.

The compressor, depending on the frequency of its rotating shaft, converts the gaseous state of the low-pressure refrigerant coming from the evaporator into a gas of high temperature and high pressure (80°C, 15 kg/cm2). The gaseous state of the refrigerant is necessary for the compressor because the liquid refrigerant cannot be compressed and this would destroy the compressor. The compressor seals the refrigerant and pumps it as hot gas into the condenser (high-pressure side of the refrigerant circuit).

Therefore, the compressor is separation place of the low and high-pressure sides of the refrigerant circuit.

In conclusion

A special compressor oil circulates throughout the system, providing lubrication to the compressor alongside the refrigerant. Systems using R12 freon employ mineral oils (with R134a, polyalkylene glycol (PAG) oils). If these oils are mixed, they form a cloudy, thick mass that can cause the air conditioning system, particularly the compressor, to fail. When adding refrigerant and oil to the air conditioner, it is crucial to use components specifically designed for this system. As a rule, there are stickers in the engine compartment of a car. They are indicate the type of refrigerant, its amount and the corresponding type and amount of oil (stickers for R134а are green, for R12 — yellow).

Car A/C Condenser repair in Dubai

From the compressor, a hot gaseous refrigerant with a temperature of about 50…70°C is supplied to a condenser, which serves to convert the gaseous high-temperature refrigerant coming from the compressor into a liquid state by releasing heat into the atmosphere. The condenser comprises curved tubes that connect with baffles and possess a large cooling surface, enabling high heat transfer. The condenser tubes and louvers absorb the heat from the refrigerant.

The refrigerant in the condenser generates heat based on the heat absorbed by the evaporator from the environment and the operation of the compressor to compress the gas. The cooling effect of the refrigeration unit depends on how effectively the condenser dissipates heat. That’s why car manufacturers usually install the condenser at the front of the vehicle and actively cool it using the air from the engine cooling fan or an additional fan, as well as the airflow created when the car is in motion. Cold outside air flows through the condenser, absorbing heat and cooling the refrigerant.

Car A/C Pressure Sensors replacement Dubai

The air conditioning system features pressure sensors 5 and 7, which prevent the system from operating when the refrigerant pressure falls below a certain value.. To control the temperature regime of the system, temperature sensors 8 and 13 are provided.

In hot local climates, no car is complete without air conditioning. Some cars feature a dual circuit for the rear passengers, adding complexity to the system but enabling independent temperature control for the rear occupants, separate from the front ones. The most common problem is compressor failure or freon leakage. Both through the valves and through the evaporator, the replacement of which sometimes results in a pretty penny for the car owner. In our garage, we carry out any work with the air conditioning and heating system with a guarantee of diagnostics and quality work.

Engine diagnostics is required if:

• Excessive consumption of fuel;
• Loss of power;
• Increased or decreased idling speed;
• Unstable engine operation
• High fuel consumption
• Error “checkengine” on the instrument panel

Sprung diagnostics is required if:

• There is a knock when driving;
• Vibration of the steering wheel;
• Found irregular rubber wear;
• Increased free running of the steering wheel;
• ABC, ESP System does not work correctly.

Diagnostics of an automatic transmission is needed if:

• One of the gears is faulty;
• Noises, kicks and skidding are observed when shifting gears;
• An oil leak is observed.

Today, computer diagnostics is the most effective and reliable way to check the condition of a car. Timely diagnostics allows you to identify faults in advance. Diagnostics reveals and details even the smallest defects, which can be eliminated in time to prevent serious damage. Thus, the car owner saves time and money on expensive repairs. It is important to remember that a working car is a guarantee of the safety of the driver and passengers.

In our services we use as dealer, such as multi-brand Dianistic equipment, such as PORSCHEPI WISTESTERII, MBSTAR, BMWICOMA + B + C, LAUNCH, VAGCOM, ODIS, Vasya, Mongoose, MDI 2, NISSANCONSULT 3,

We also perform cloning, programming and coding of control units and computers of any car brands