A to Z Performance Tips

[amsyl]

A to Z Of Performance Enhancements

By Sylvester Lim

A

Aerodynamics – Car manufacturers spend millions of dollars performing wind tunnel testing to ensure that the shape of the car is streamline or have a low Cd (Coefficient of Drag). The Cd of a car is affected by how air flows through the car’s body. Any change such as adding roof racks on the car will increase the Cd and incur higher fuel consumption as well as lowering your top speed.

Air filter -  Most cars, if not all of them will benefit from a change of the air filter. Cone-type or Open-Pod air filters are popular with many tuners. By increasing the surface area of the air filter element, more air is able to enter the engine offering better performance. However, taking in hot air from the engine bay reduces power from the engine. Given our high ambient temperature and the fact that we drive with the air-conditioner switched on most of the time, the engine bay acts like an oven. The air temperature can go up to as high as 70 degrees C on a hot day. Unless the cone air filter is fed with cool air, many cars will lose power in the low and mid-range and their throttle response as well as increasing their fuel consumption. More cool air means more power as cool air is denser and contains more oxygen molecules. You can feel a better engine response when driving at night or in the early morning versus a hot afternoon and the difference in the ambient temperature is only about 6 degrees C. If your engine is taking in lots of hot air from the engine bay, forget about any power gains. As a guideline on the temperature of the air intake, every 5 – 10 degrees C makes 1% of power.

Changing your original air filter to a replacement element can help improve air intake a tad, but don’t expect too much from it. This replacement air filter element offers a higher level of air flow especially when it gets dirty compared to the original air filter element.

Air Fuel Mixture Controller AFC – Most modern engines depend on electronic fuel injection and the air & fuel mixture are preprogrammed at the factory. This however, does not mean that you cannot change the parameters. The AFC fools the ECU/computer by changing the signals from the airflow sensor. The ECU increases fueling when it thinks that more air is flowing thru the engine. This feature allows you to reprogram the air/fuel mixture to match the modifications to the engine. However, it is best to tune it using a dynamometer or the very least, with an Air/Fuel Ratio Meter so that you can adjust the air/fuel mixture correctly. Check out models from ADM, HKS, Fields, APEXi, Unichip & Obit. The snazzy display on the APEXi unit turns on many drivers but programming it wrong will make the car a dog to drive and reduce fuel consumption. (Also See Programmable ECU).

Air Fuel Meter – Taps into your Oxygen or Lambda sensor and has little LED lights that tell you the air & fuel mixture. This meter can great for tuning your car for optimal performance and impressing your friends as the LED moves around. For highly tuned engines, this gauge can help ensure that it never runs lean to the detrimental of its good health. Engines develop maximum power with the air/fuel ratio of 12.5:1 to 14:1 and good fuel economy at 16.2:1 to 17.6:1 (parts of air to parts of petrol). Note that this are narrow-band sensors and are not as accurate and quick as the wide-band units used by tuners.

Alloy Rims – The Alloy Sports rims for the same diameter are lighter than steel rims by as much as 5 kilograms on each corner. With less unsprung weight at each corner, the suspension system is able to work better at handling undulations on the tarmac. Less weight means better acceleration as well due to the lower inertia. Most people would upsize the rims when changing to alloy rims and this will negate the weight savings as bigger rims and wider tyres are heavier.

Anti-Roll Bars – Also known as Anti-Sway Bars are usually fitted on both front and rear suspension to reduce body roll. Because it helps to keep the car relatively flat under hard cornering, the tyre contact with the road is maximized and gives better traction. Changing to an uprated or thicker anti-roll bar improves handling by reducing body roll without compromising ride comfort. Changing the rubber bushing of the anti-bar to harder units will also help to increase the stiffness of it. Expect to spend about $500 for a set of uprated anti-roll bars.

B

Back pressure – Normally associated with restriction in an exhaust system. Less back pressure means better exhaust flow and additional power/torque gains as well as more exhaust noise. Some workshops claim that some back-pressure is good for normal aspirated engines. However, dynotests have shown that less back pressure means more power across the rpm band with the air/fuel ratio, ideally readjusted. (See Exhaust).

Body Kits – This certainly helps the car to stand out from a sea of lookalikes. The body kit also reflects the car owner’s character as do the interior of the car. Simple add-ons to the front lip, sideskirt, rear lip and a small rear spoiler can transform your car from a mundane transport into a sporty looking road burning machine and is complimented by 16 or 17inch rims and low profile tyres. Unfortunately, they also attract the Traffic Police and don’t like road humps very much. The cheaper fiber-glass type are quite fragile and can crack easily.

Boost Pressure – One surefire way of getting more performance from a turbo or supercharged car is to increase boost pressure. However, it is also easy to blow up your engine for being greedy. Usually done by adding a bleed valve at the wastegate that controls the amount of boost. HKS & Greddy have an electronic controller unit that allows you to program the boost level as well as how much of boost and at what rpm. Looks impressive on your dashboard and will surely impressive your girlfriend. A simpler version is a gated valve from an Australian company called Turbosmart.

BHP – Brake Horse Power. Power is the rate of doing work and is measured in Kilowatts (Kw). The Power of an engine (Kw) is equal to Torque (Nm) x Rpm divided 9548. Without torque, there is no power. European 1 bhp is slightly greater than the Japanese 1 ps. Many people tend to prefer cars with high horsepower specification but forget that a good range of torque is more important for everyday driving. What is the use of having a super duper engine developing its maximum torque at 6000 rpm when you change gears at 3000 rpm?

Brake Fade – Loss of brakes when slowing down at high speeds is called brake fade. This happens when the brake pads are overheated and boils the brake fluid. Usually happens to heavy cars or modified cars with greater horsepower than the brakes can handle. Changing to performance brake pads and DOT 4 or DOT 5 brake fluid helps to reduce this and increase braking power. Brake fade happens to many cars found wrapped around trees due to late braking techniques. See below.

Brake Pads – One low cost method of uprating your braking system is to change your brake pads to the performance type. These pads have a higher heat range and can take more punishment that the normal type. Avoid racing pads as most of them need to be warmed up before using them. Some well known brake pads are Endless, SRS, Mintex. Ferodo, EBC, Bendix.

C

Camber – The angle of the wheel when looking at it from the front of the car. Race cars have lots of negative camber in the front, that is, the top of the wheel is closer to the body whereas the bottom of the wheel is further apart from each other. Under hard cornering, a wheel without camber will end up wearing the sidewall of the tyre and losing grip faster. A wheel with adequate camber will have a larger surface area when cornering hard and hence, more grip. One drawback with too much camber is that the inner tyre wear will be increased.

Camshaft – For normal aspirated cars, a performance camshaft improves the breathing of the engine and hence develops more power and torque. The inlet and exhaust valves open longer and higher allowing more air to enter combustion chamber. However, expect some increase in fuel consumption and radical camshafts have poor idling characteristics. For street cars, go for cams with less than 270 degrees duration if you do not want poor idling characteristics. Race-type camshafts gives you a lumpy engine that makes people think you have a sick car. Most performance camshafts move the power and torque band higher up the rpm band. For SOHC engines, the cams cost about $1K whereas for DOHC, about $2K with power increases ranging from 8 bhp to 20 bhp.

Catalytic Converter – Also known as ‘Cats’ and are not related to felines. This Muffler-like unit in the exhaust system that helps to reduce harmful gases in exhaust gases. Unfortunately, it can also increase fuel consumption as it restricts exhaust flow slightly. The restriction in exhaust flow is more significant in models where the ‘Cat’ is closer to the engine and the exhaust extractor. Some people remove the cat for better performance but break LTA laws. It can glows red hot after a hard drive and car manufacturers advise drivers not to park over dried vegetation as it will catch fire along with your car and hopefully without you in it. For the environmentalists, performance hi-flow catalytic converters are available and are permitted by the LTA.

Chips – Not potato chips but computer chips or EPROM Electrically Programmable Read Only Memory, the brains of the automobile. It tells the fuel injection system the amount of fuel to deliver, ignition timing and controls some automatic transmission systems. Performance chips such as those from SuperChip, PowerChip & StarChip reprogram the standard program to be more performance oriented by increasing fueling curve and a more aggressive ignition timing. Performance gains for normal aspirated cars range around 10% whereas for turbo/supercharged cars, 20% or more gains are easy to achieve. Not for DIYers as breaking a pin or two on the circuit board will set you back a couple of thousand dollars. New piggyback ECUs that ride on top of the standard ECU such as ADM Tuning Box, Unichip, Obit, E’Manage and SMT-6 can be programmed to fool the original ECU. The performance chips and piggyback ECUs range from $500 to $900. (See programmable ECU).

Clutch – Performance Clutch kits are a must have when there is a large increase of engine power as it will overwhelm the standard clutch and burn it out. An uprated pressure clutch cover with a stiffer diaphragm and an uprated clutch plate ensures that the clutch does not slip easily. 3-paddle/puck metallic friction disc are mainly used by racers and can make you drive like a learner as the transmission jerks when the clutch bites. You develop strong left leg after prolong use and standard clutches feel wimpy after this.

Compression Ratio – It is a measure of much air & fuel mixture is compressed in the combustion chamber. The higher the ratio, the more air & fuel mixture is burnt and the more power is developed. The used of high compression pistons are normally swapped for the standard ones to improve power. Engine runs hotter than standard because of the heat generated. The compression ratio is normally reduced on turbo/supercharged engines to ensure that engine detonation or pinking is kept at bay. See Turbocharging and Supercharging that essentially does the same job of forcing more air & fuel into the engine.

Coating – A ceramic based layer of heat resistant coating is applied to the exhaust manifold, turbo housing to keep the heat within the exhaust system. Thermal wraps are often used but needs to be periodically maintained. This helps to reduce under-bonnet temperatures and is supposed to increase the flow of the exhaust gases. Power increases is marginal through the increased exhaust flow as most will get improvements from the lower under-bonnet temperatures. The power gains are more obvious on turbo engines.

Crank Pulley – The crank pulley drive various components such as the aircon compressor, power steering and alternator. Changing to a lighter version helps to reduce the rotating inertia of the pulley and gives the engine a lighter more torque. The crank pulley is linked to the crank and flywheel. See Flywheel

Cyclone – A device placed in the intake pipe that is supposed to swirl the intake air into the combustion chamber and create a mini tornado. Also known as ‘Surbo’ that claims to have a turbo effect.

D

Dampers – Commonly called shock absorbers but these do not absorb shock or road undulation. The job of handle shocks or jolts from the road is performed by the springs. As the springs oscillate when they encounter bumps, the dampers are used to stop this oscillation so that the tyres can do their jobs. For the performance driver, if the budget allows you to, change to top adjustable ones such as the Koni Sports. They are not the best money can buy, but, they are value for the money. The Monroe Sensatrac dampers also good replacement units for drivers with good comfort levels in mind but like the OE ones, do not work well with lowered springs.

Disc Brakes – All cars have front disc brakes (a round, shinning and flat metal plate inside the wheel) and some for the rear as well. Performance brake discs are slotted or grooves cut into the discs, some are crossed drilled or both. This helps to dissipate the heated gases trap between the brake pads and discs when braking hard reducing heat build up and brake fade. See Brake Fade. High performance models use large disc brakes and 4-pot or 6-pot brake calipers to increase braking performance. The larger brake surface area provide more friction when braking and these cars now stop on a dime. You can uprate your brakes by using the braking components from a larger model. For example, using the Mitsubishi Galant front brakes on a Lancer or Honda Accord on a Civic. However, some modifications are required to mount them. Although many family saloons make do with drum brakes for the rear and not disc brakes, the drum brakes provide more than adequate braking performance as 70% of the braking force is at the front. Replacement discs brakes are available from DBA, Sparco, Tarox whereas the high-end racing versions are from AP Racing, Alcon, Brembo and Wilwood. Performance replacement brake discs start from $400 while the 4-pot calipers and corresponding brake discs start from $1500.

DOHC Double Over Head Camshaft – Engine with two banks of camshafts with one set controlling exhaust valves and the other intake valves. DOHC engines normally have 4 valves per cylinder and provide more power and torque for the same engine capacity. DOHC stickers are seen often on the sides of cars that don’t go very fast. Changing to performance camshafts cost more as you need two of them, one of the inlet and the other for the exhaust. DOHC engines are generally smoother when revved hard.

E

EFI Electronic Fuel Injection System – See Chips & Fuel Regulators. EFI systems relies on signals from sensors such as air temperature, MAP Manifold Absolute Pressure or Airflow Sensor, throttle position sensor, crank position sensor, water temperature sensor and others. Due to tough emission standards, carburetors are dead as an EFI system is more efficient and offer better fuel consumption, power and less toxic emission. Some models adopt the Single Point Injection System (an improvement of the carburetor) while most now use Multi-Point Injection system.

Exhaust – A good exhaust system that expels gases efficiently helps the engine to make more power. Does not mean the louder it is, the better it works. Some high flowing exhaust systems are reasonably quiet. Many boy-racers love the sound of their loud exhaust but cannot drive to save their mothers. Too big an overall diameter exhaust system can reduce low & mid range torque but kicks butt at the top end. Large tail pipes at the rear attract the Traffic Police like flies to a fruit. As a rule of thumb, the overall diameter of the exhaust system for normal aspirated engines are: 1.3 cc – 1.875 inches (min. 1.75 inches), 1.6 cc – 2 inches (min. 1.875 inches), 2.0 cc – 2.25 inches (min. 2 inches). Currently, some versions from Remus and Super Sprint have got LTA approval.

Electric Supercharger – A mild form of forced induction that helps to push more air into the engine. This high flow 12V electric blower can provide up to 10bhp of power and 10 – 18% of torque on a number of engines and because it is electrically powered, there are no associated parasite power losses. They basically improve the breathing abilities of an engine allowing it to develop more torque and horsepower as if it is a bigger engine. Products such as the ADM Air Charger has a variable speed system with an electronic controller.

[amsyl]

Part 2

F

Flywheel – A relatively heavy disc fitted to the crankshaft to smoothen the engine against the uneven beat of the pistons. A lightened flywheel will make the engine spin up faster offering better acceleration. Some metal is machined off the outer perimeter of the flywheel to lighten it. Or alternatively, purchase a ready-made billet aluminum alloy flywheel. Take too much weight off without balancing it will cause a rough engine. Without a heavy flywheel, the engine bogs down more easily and requires more revs to get off the line.

Fog Lights – Used to improve visibility on foggy days in other countries. Local cars use them at night to rudely get motorist to get out of the way. LTA only permits switching on of the fog lights on hazy days and frown on non-factory fog lights.

Fan-Cooling – Most modern cars use electric fans to cool the radiator and allows engine to run cool on very hot days. Getting the engine to run cooler helps to build more power and torque. Changing to a lower rating fan switch (85 C) and thermostat helps to lower the engine temperature. Older cars still using belt driven clutch fans can convert to electric ones and benefit from the increased performance. Never run a car without a thermostat as it takes longer to warm up the engine and engine oil to the optimal operating temperature.

Fuel Filter – A forgotten item that most mechanics ignore. Muck in your petrol tank gets trap in the fuel filter. Unfortunately, a clog fuel filter will restrict your petrol flow and starve your engine. You will be surprised by the difference in performance from just changing or just cleaning your fuel filter every 40,000 km. Racing fuel filters have higher flow rates and are easily cleanable.

Fuel Pressure Regulator – Is used to maintain a constant fuel pressure to the fuel injectors and increases fuel pressure under acceleration. See Power Boost Valve.

Fuel Pump – The unsung hero in a fuel injection system. The fuel pump must provide adequate fuel pressure 70 psi or higher and petrol flow for an engine to develop its maximum performance. Over time, the fuel pump becomes less efficient and does not flow sufficiently. As it is located inside the fuel tank in most cars, it may be the cause of your hesitation under WOT wide open throttle that you have been trying to solve.

Final Drive – By changing the final drive gear to a lower ratio, that is, from a 3.9:1 to 4.4:1, acceleration is improved. Unfortunately, top speed is reduced and at a constant speed, the engine rpm is higher and hence, a penalty on the fuel consumption. This involves the changing of the crown wheel and pinion gear by stripping the gearbox.

G

Gauges – Not only turbocharged model can enjoy having a plethora of gauges for vacuum/boost, oil pressure, oil temperature, voltmeter etc. Normal aspirated cars can enjoy these gauges either for keeping an eye on the engine condition or just for the sporty aesthetics. A vacuum gauge will be a welcome addition for most cars as it can be used to find out the condition of your engine as well as whether you are heavy or light on the throttle. While moving, the higher the vacuum reading, the more economical your driving. For the enthusiasts, a tachometer with a shift-light (reminds you to shift gears) is a nice addition.

Ground Wires – Additional shielded heavy gauge wires fitted from various parts of the engine directly to the battery negative terminal helps improve the electron flow thru the sensors as well as the ignition system. This in turn improves performance. Ground Wire Kits are available but can also be DIYed.

I

Ignition – Provides the spark that lights up the air & petrol mixture in the engine combustion chamber to push the pistons that in turn provide the turning force. Main components consists of ignition coil, ignition cables and spark plugs. Older cars permit the changing of the ignition coil to higher rating units but most modern cars have DIS (Direct Ignition System) that makes it almost impossible to change. High performance engine use CDI Capacitive Discharge Ignition to boost the ignition system especially at the top end where it is most needed. Multi-Spark Ignition Systems generate multiple sparks with each ignition cycle below 3000 rpm and just larger sparks at higher rpms. This ensures maximum combustion even at high rpm levels.

Ignition Cables – Just changing the standard ignition cables which are more than a year old to performance types can improve performance as the normal carbon cables are cheap and do wear. The enhanced sparking achieved will ensure that all the air/fuel mixture is completely burnt. Some performance ignition cables have 3 or 5 cores to improve conductivity. Whether it is 8mm or 10mm does not matter as it is just the thickness of the silicon covering. The performance cables must provide adequate protection from EMI Electro Magnetic Interference as it will mess up the signals in the engine’s electronics.

Injectors – Changing to large injectors will increase the amount of fuel into the engine. However, without reprogramming the ECU or using electronic devices to fool the air flow sensor, too much fuel will be supplied as the ECU will continue pulsing the injectors as per normal. A change to larger injectors will be useful if you have increased engine capacity or changed to a larger turbo or supercharger.

Intercooling – A radiator used to cool the intake air of supercharged/turbocharged cars. Boosted(compressed) air is heated up and as cool air is less dense, more power can be found by cooling the air intake. A water spray on the intercooler that turns on only under high boost helps to reduce the heated air further.

L

Limited Slip Differential – Also known as LSD and does not come in tablet form. Most gearbox differential allow a large amount of slip during turns and the inside wheels spins easily because of the loss of traction. Fitting a LSD limits the amount of slip giving more torque to the outside wheel and helps to reduce understeer in front wheel drive cars when powering out of corners as well as straight-line launches. Highly recommended for high powered cars and competition. The plate-type versions as best used only for competition as they are noisy and requires maintenance. For street use or mild competition, the Quaife LSD uses a gear system to progressively lock the differential. A low cost option is the Phantom Grip that modifies the standard differential into a LSD. Some 4WD models use a viscous LSD or a type of silicon-based fluid to control the locking of the differential.

M

Multi-Point Injection System – A MPI system has multiple fuel injectors for each engine cylinder. With more accurate fueling characteristics, an engine with MPI system can develop more power and has more scope for further modification compared to a Single Point Injection System.

Magnets – Products such as the Calski Ion Accelerator, Power Max 2, RMK Magnafuel use powerful magnets to help agitate the fuel molecules to improve combustion. This gives better performance and fuel consumption.

N

Nitrous Oxide – Also known as laughing gas, NOS and power in a bottle. NOS is 36% oxygen in content and the rest is nitrogen that acts as an excellent cooling agent. More oxygen & fuel means more power and a power gain of 25 – 50 bhp is easily obtained from a basic system. It is turned on only at wide open throttle and provide about 100 times of 1 – 2 second burst of NOS. A cheap method of getting more horsepower but need refills and is illegal under LTA rules. Popular brands are NOS Nitrous Oxide Systems, ZEX, NitrousWorks, and Nitrous Express. A progressive Nitrous system that injects metered gas would be a better option but is rather expensive.

O

Octane Rating – Tells you the anti-knock quality of a petrol and is measured in RON Research Octane Number. Local oil companies sell petrol with a RON rating ranging from 92 to 100. Most cars are designed to run with 95 octane petrol and unless your engine management can be tuned for the higher octane petrol, it makes no difference what so ever. Engines that incorporate a ‘knock’ sensor can optimize the fuel used such as 98 RON given our higher ambient temperature. Higher octane petrols are more important to turbo/supercharged & high compression engines. Because oil companies use various types of fuel additives to their petrol, some do provide better added performance and Fuel Consumption. Don’t ask us which one, just test out various types each week.

Oil – Whether mineral or synthetic based engine oils, they are the lifeblood of your engine. Low viscosity oils such as SAE 20, 30 or 40 are thinner and reach engine parts faster on cold starts. Older engines need to use thicker oils such as SAE 50 because of the wear and tear of the engine. Forget about the first number with the W such as 5W or 10W as we do not have winter locally. Like petrol, engine oils are different and some do help to increase engine performance. Synthetic oils though more expensive than mineral oils offer better protect against heat and wear. When running in engines, use mineral based oils.

P

Power Boost Valve – An adjustable fuel pressure regulator that increases fuel pressure under acceleration. Because it increases fuel pressure faster than the original fuel regulator, it helps to reduce ‘flatspotting’ or hesitation and works even better with a change of performance spark plugs/cables and air filter. Don’t go overboard with the fuel pressure or your air/fuel mixture will be too rich. Many cars run better with a lower fuel pressure. On new car models, the PBV works well with Lancer and Mazda 2/3/6.

Programmable ECU – Engines that have been highly modified so much so that the standard ECU is unable to match the fueling and ignition timing requirements, it will be best to have a programmable ECU installed. ECUs such as Motec, Autronics, Apexi Power FC, Wolf 3D, Microtech are complete ECU replacement units and should not be compared with cheaper piggyback ECUs such as Unichip, Obit and Smart Tuner SMT-6. The Microtech ECU is one of the lowest cost entry level replacement ECUs. These ECU replacement units have faster processors and response rates. However, other than the Apexi Power FC, the rest have to be programmed from scratch. The programmable ECUs are only as good as the person who sets up the software in these systems. Unless there have been major modifications to your engine, your standard ECU should be adequate enough.

R

Resonator Box – A hollow plastic box sometimes placed along the standard intake and before the air filter box. This helps to reduce the sound of the air rushing into the engine. However, they create a turbulence within the intake system and at times disrupt the air flow. Removing them will help ‘smoothen’ the air flow but will increase the induction sound slightly.

Ram Air Induction – By placing a forward facing duct in front of a car and feeding the air to the air filter box, a fast moving car can help feed more air to the engine. While this is only effective only at high speeds, even at 80 kph, there is a slight improvement to the engine response. The disadvantage is that the air filter will get dirty faster and needs to be cleaned more frequently.

S

Spark Plugs – They do make a difference to performance as it helps with improving sparking especially at higher rpms and in high performance engines. There are many brands available such as Bosch, NGK, Splitfire, Champion and Denso and they come with various center electrodes such as Copper, Platinum and Iridium. Very importantly when choosing a spark plug for your car, get the correct heat range and electrode gap for your model or you will loose performance due to fouling spark plugs.

Supercharging – This is basically an air pump which forces more air/fuel mixture into the engine giving you more power with the same engine capacity. A supercharger is normally belt driven just like your airconditioner and because it operates almost all the time, the power gain is instantaneous. The supercharger is found on some Mercedes models and VW Corrado. Supercharger Kits are available from Jackson Racing and Vortex for Honda models. The kits are priced from $5000 to $9000.

Stuffed Toys – Mainly found on the rear parcel shelf hindering rear vision of the driver. Used to highlight driver’s poor driving ability and inconsideration to other road users especially motorcyclists. ‘I drive like a jerk and that’s why I don’t need to use the rear view mirror’, attitude. Need to decorate your car? Try using stickers!

Suspension – Lowering your car by an inch or 25 mm improves your car’s cornering ability as it reduces your car’s CG Center of Gravity. While it reduces body roll, ride comfort is consequently reduced. Going too low will make it a pain on poor roads and road humps. Most lowered springs don’t work very well with the standard dampers as the higher springs rates will overwhelm the soft dampers and cause spring oscillation similar to that of a suspension system with faulty dampers. Progressive springs are better for normal road use as they progressively get harder when compressed such as when cornering. Linear springs are normally used for racing purposes. Available in the market are lowered springs such as Eibach, Sparco, Tein, Hotbits, KG/mm and Merwede. See Anti-Roll Bars and Dampers.

Stroking – By changing the distance the piston has to travel in the cylinder bore, you are effectively increasing the amount of air/fuel mixture into the combustion chamber and hence, the engine capacity. This involves the changing of the conrods and crankshaft, a major engine modification and highly illegal as it changes the engine capacity. Prices range from $2000 to $5000.

Speed Cut – Some Japanese models incorporated a 180 kph speed limit to their cars due to the Japanese Road Authority requirement. For speed demons or those who enjoy high speed jaunts to the North South Highway, the speed cap can be a pain. The Speed Cut can be disabled thru the use of electronic addons from HKS, Blitz, Field and Apexi. Prices start from $200.

Short Shifter – By reducing the throw of the gear shift or the distance when shifting gears, changing gears is quicker. This involves the changing the whole gear lever and as it has a different leverage, changing gears is slightly heavier and more notchy.

Spring Adjuster – Fitting the Splitfire Springs Adjusters helps to stiffen up the springs to improve load carrying, handling characteristics, reduce bodyroll and understeer as well road clearance on cars with lowered suspension. This effectively upgrades the stock suspension system.

T

Torque – The twisting force of an engine and is measured in Newton Metres Nm. For normal driving, the lower the rpm the maximum torque develops, the better the engine response. For example, an engine making 150 Nm @ 3000 rpm will be more responsive at below 5000 rpm versus an engine developing 170 Nm @ 6000 rpm. The latter will be good for racing and high performance driving. See BHP.

Turbocharging – Another air pump except that it uses the exhaust gases to turn the compressor wheel. Below 3000 rpm, the engine response sucks as the turbo needs to build up speed. When the turbo kicks in, the power rush is addictive. Getting lots of cool air is imperative to better performance. Many modified turbo cars can be identified by the ‘PSTSS’ sound it makes at every gear change caused by the dump or blowoff valve. Turbos are found on models such as the Impreza WRX, Lancer Evolution, Nissan 200SX, Volvos, Saabs etc.

Tyres – The four tyres of a car has a contact area with the tarmac the size of an A4 paper. Hence, the tyre compounds & design are important in improving grip, cornering and braking distance. Each brand of tyre has variety of tyres catering to different budgets and remember, you pay for what you get. A good tyre can make a difference especially in the braking distance and can pay for itself many times over by saving you and your family once from an accident. Many drivers cut corners by saving on tyres and spend thousands on a stereo system. Try getting a stereo to save your butt!

Tyre Pressure – By checking your tyre pressure and following the manufacturer’s specification every two weeks, you ensure the optimal fuel efficiency and reduce tyre wear and tear. Not to mention reduce the possibility of your tyres losing traction in poor weather condition, hard cornering and under braking.

V

Voltage Stabilizers – A simple product fitted between the battery terminals. They help to increase charge efficiency to the batteries with the effect similar to having a new battery all the time.

W

Weight – Carry additional stuff in your trunk such as a set of golf clubs, a filled water container, spare battery, catalogues and magazines (Wheels magazine is okay) are actually increasing the curb weight of the car. As the engine has to work harder with this additional load, you will increase your fuel consumption and reduce acceleration just as if you are having another passenger in the car all the time.

Water Injection – Unlike the water spray system used to cool an intercooler, the water injection system sprays a fine mist of water inside the intake system and is normally located before the throttle body. A water injection system is normally used in forced induction (turbocharged) engines and helps to reduce the temperature of the heated air as well as reducing the possibility of detonation in the combustion chamber.

Wheel Alignment – Most car manufacturers setup front wheel drive cars to understeer as it is the safest characteristic for most drivers. For the enthusiasts, by changing the wheel alignment, you can change the handling characteristics for the car. By reducing toe-in to a slight toe-out or zero toe, turn in at corners will be sharper however straight-line tracking is slightly compromised. For normal drivers, ensuring that your wheel alignment is at manufacturer’s specification reduces tyre wear and tear. When changing any of the suspension components, always send your car for wheel alignment.

Copyright By Sylvester Lim – Singapore