Tyre Safety

Tyre Maintenance - Your Most Important Safety Item

Your tyres are the only contact between you and the road and, like your vehicle, they too require regular maintenance.

Tips

Check your tyre pressures regularly, once a fortnight is recommended and ideally when your tyres are cold. Inspect tread and sidewalls for cuts and abrasions, bulges, unusual wear and road damage.

If the tyre receives a severe impact, ask your tyre retailer to check for internal damage. Do not repair cuts in sidewalls of radial ply tyres.

Avoid using 'sealants' or other liquid preparations to prevent deflation. These may cause the valve to stick open slightly, causing pressure loss and indirectly causing corrosion of steel belts.
Driving on under inflated tyres is almost certain to cause serious damage, always inflate tyres to the suggested pressure.

Take action immediately to rectify any unusual sounds or vibrations. Tyre balance and vehicle wheel alignment should be checked regularly, (ie every 10,000km), especially if your tyres are subjected to rough roads or aggressive driving.

Tyre wear on front wheel drive vehicles is a little higher and therefore, attention to tyre pressures as well as rotation should be made on a regular basis.

Suspension

Suspension ialah asas mekanisme system hidraulik yang mengawal getaran spring, ia sebenar bukan menanggung keseluruhan bebanan atau mengembalikan kedudukan asal selepas pergerakan ke atas dan ke bawah, pembalikan Cuma boleh dibuat oleh spring sahaja. Oleh itu badan kenderaan “body” terletak diatas spring dan “suspension” yang mengawal pergerakan apabila spring menerima tekanan disebabkan oleh bonggol yang menyebabkan ia bergetar. “Suspension” mengawal pergerakan spring dalam kesemua arah ketika spring termampat atau ketika spring mengembang dan jumlah rintangan yang diperlukan dalam tiap-tiap arah “up-down” ditentukan oleh jenis dan saiz kenderaan tersebut.

Mengesan Kerosakan Pada Suspension

• Ketika anda sedang memandu kenderaan dan melanggar lopak atau bonggol, kenderaan anda akan bergegar dan kurang selesa. Ia adalah kerana “suspension” sudah tidak berfungsi (hilang keanjalan).
  

• Jika anda sedang memandu sambil mengambil selekoh tiba-tiba terasa kenderaan anda hilang kawalan dan tidak stabil, ini kerana “suspension” tersebut terlalu lembut, ini adalah kerana spring telah hilang keanjalan.
  

• Sekiranya anda mendapati tayar kenderaan anda menjadi tidak rata serta cepat haus ia adalah kerana ‘absorder’ dan spring tidak berfungsi dan menyebabkan segala gegaran akan diserap oleh tayar.
  

• Sekiranya terdapat bunyi seperti belagar (besi) ia adalah berkemungkinan “bush absorber” dan spring tidak menyerap gegaran antara casis dan spring.
  

• Sekiranya terdapat kerosakan berikut sila rujuk pada bengkel berdaftar atau pusat servis yang berdaftar.

Cara-Cara Penjagaan “Suspension”

• Untuk menjaga “suspension” anda tidak membawa bebanan yang berlebihan mengikut saiz dan jenis kenderaan.
  

• Sekiranya anda kerap membawa muatan pastikan anada membuat pemeriksaan pada “suspension” dan menggunakan “absorber” serta spring yang bersesuaian untuk tugas tersebut.
  

• Untuk menjaga “suspension” serta rim dan tayar, elakkan daripada melanggar lopak dan lubang serta tidak melalui jalan yang tidak rata.
  

• Sentiasa memastikan penjajaran tayar kenderaan di dalam keadaan baik
  

Article contributed by AAM

Intercoolers

Front mount intercooler

An intercooler’s purpose is to cool air that has compressed in either a turbo or supercharger. When air is compressed its temperature rises drastically, upwards of 300 degrees Fahrenheit, and becomes less dense and less oxygen rich. An intercooler is an essence a heat exchanger, like your radiator.
There are 2 main types of intercoolers air to air and air to water. An air to air intercooler uses outside air to transfer heat, while a air to water uses water to transfer heat.

In an air to air intercooler cool air passes through the intercooler tubes heating both the tubes and eventually the cooling fins. At the same time air from the outside passes through the fins of the intercooler, the heat from the tubes and fins is transferred to the air passing by on the outside. When it comes to an air to air intercooler setup there are different locations setups, different inlet and outlet configurations and different sizes. Locations for a front mount intercooler include, side mount intercooler and top mount intercooler. The location of the intercooler is key when determining how effectively it will transfer heat. The optimal location is a spot where the intercooler will have forced outside air blowing directly on it without any interference. This is why front mount intercoolers are very effective at transferring heat. They sit directly at the front of the car so they constantly have air from the outside blowing through the intercooler fins. Usually the only negative argument for a front mount intercooler is pressure drop. Pressure drop occurs because the route the air has to take to make it from the turbo to the front mount intercooler to the engine is long and not direct. Many front mount intercoolers today have been designed to help air flow and decrease pressure drop almost to a non-issue.

Top mount intercooler

Another cool setup I like is the hood scoop scooping in air directly to a top mount intercooler, like a Subaru Wrx. A major disadvantage to this is that your intercooler sits close to your engine which heats up your intercooler drastically reducing its efficiency for heat transfer. An advantage to this setup is that the air flow route from the turbo to intercooler to engine is short creating a more responsive setup.

A water to air intercooler is much like an air to air intercooler but this setup uses water to transfer heat instead of air. Since water is much better at transferring heat than air, you can have a smaller cooler which makes installing and finding an optimal location/setup much easier. In this setup water is pumped through the air/water unit where it meets the compressed air. Here the heat from the air is exchanged to the water. After the water has been heated it follows a path to a heat exchanger, like an intercooler or radiator where the heat is then transferred out of the water. Some obvious disadvantages that are inherent to a water-to-air setup are weight and mechanical malfunctions.

How Car Cooling Systems Work

Diagram of a cooling system: how the plumbing is connected

Although gasoline engines have improved a lot, they are still not very efficient at turning chemical energy into mechanical power. Most of the energy in the gasoline (perhaps 70%) is converted into heat, and it is the job of the cooling system to take care of that heat. In fact, the cooling system on a car driving down the freeway dissipates enough heat to heat two average-sized houses! The primary job of the cooling system is to keep the engine from overheating by transferring this heat to the air, but the cooling system also has several other important jobs.

The engine in your car runs best at a fairly high temperature. When the engine is cold, components wear out faster, and the engine is less efficient and emits more pollution. So another important job of the cooling system is to allow the engine to heat up as quickly as possible, and then to keep the engine at a constant temperature.

The Basics

Inside your car's engine, fuel is constantly burning. A lot of the heat from this combustion goes right out the exhaust system, but some of it soaks into the engine, heating it up. The engine runs best when its coolant is about 200 degrees Fahrenheit (93 degrees Celsius). At this temperature:

• The combustion chamber is hot enough to completely vaporize the fuel, providing better combustion and reducing emissions.
• The oil used to lubricate the engine has a lower viscosity (it is thinner), so the engine parts move more freely and the engine wastes less power moving its own components around.
• Metal parts wear less.

There are two types of cooling systems found on cars: liquid-cooled and air-cooled.

Liquid Cooling
The cooling system on liquid-cooled cars circulates a fluid through pipes and passageways in the engine. As this liquid passes through the hot engine it absorbs heat, cooling the engine. After the fluid leaves the engine, it passes through a heat exchanger, or radiator, which transfers the heat from the fluid to the air blowing through the exchanger.

Air Cooling
Some older cars, and very few modern cars, are air-cooled. Instead of circulating fluid through the engine, the engine block is covered in aluminum fins that conduct the heat away from the cylinder. A powerful fan forces air over these fins, which cools the engine by transferring the heat to the air.

Blow Off Valve - HKS Super Sequential

Ever wonder why rally cars make that sound you hear when you open a bottle of pop? Well, maybe not exactly like that but more or less similar to the sound of air being released (air, not gas!). You usually hear this when you let off the throttle, sorta sounds like a woosh!. In effect, what you are hearing is the sound of built up boost pressure being released from the intake system. The reason for this is that the turbocharger will keep spinning even after you let off the gas. So as you close the throttle plate, allot of pressure builds up in the intake system. This becomes problematic in that this excess pressure can cause the turbines to seize. Ultimately, this would destroy the turbo unit. For this reason, we incorporate BOV's, bypass or diverter valves. These mechanism work because on the other side of the throttle plate, vacuum gets built up in the intake manifold. Blow off valves, diverter and bypass valves all work by detecting this vacuum. Having done so, they use this vacuum to mechanically open a valve in order to relieve unnecessary boost from the other side of the throttle plate.

Forge Diverter/Dump Valve

Now let us differentiate BOV's, diverter and bypass valves. First, a blow off valve (seen top ) is common to high performance applications in that it provides the least bit of compromise. A BOV essentially releases this pressure straight out into the atmosphere. Quite often you will find that these units take on particular shapes, making them resemble musical instruments. I guess some people out there really like to flaunt their gadgets. Just wait ti'll you see how much they impress the ol' 5-0. Aside from this legal dilemma, the second problem you encounter with BOV's is that the mass air flow sensor will cause the engine management system to "think" that the air will go into the engine and in turn will release an appropriate amount of fuel for it. However, a BOV system will vent this air out before it gets to the injectors causing your mixture to run lean. In turn, this will result in unburned fuel to escape into the exhaust system. This is why you often see flames and hear those "pop's" in rally cars. It is unburned fuel exploding in the exhaust system. Doesn't take a genius to figure out that this is not the smartest application for the day to day car. For this reason, reasonable tuners will usually employ a bypass or a diverter valve (see left). These units essentially redirect this pressure back behind the compressor causing the net flow of air to remain constant. This in turn slows the turbine down gradually and allows the air flow sensor to work appropriately.