• Data shows it takes about 90 seconds for an average 5-year old car’s engine to warm up and reach its thermal efficiency. According to IAM, reversing out of a parking bay while the engine is cold takes up between 20-25 times more fuel than when it is warm. Apparently driving away forwards will help you save fuel. Could be related to the usually lower gear ratio of the reverse gear compared to the first gear.
• The UK’s Highway Code actually encourages reverse parking. This is because reversing into a parking bay which remains static (just an empty piece of road/cement, nothing will suddenly fill it up) is safer than reversing out into a road/lane which may have constant traffic where you cannot see easily. Driving out forwards into the road makes it easier for you to look out for incoming traffic.
• Reversing close to a wall may make it more difficult for thieves to break into your boot as there will not be enough space for them to work.
• With the amount of crime these days, it is easier to get out of the parking bay as fast as possible driving forward as it is easier for you to see where you are going in case you have to leave as fast as you can for security reasons.

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.

I did a short survey with the people on my instant messaging list and almost everyone said they’d either change the pair that is more worn out, or change the ones at the front because the car is front wheel drive – unless the rears are for some reason more worn out. It’s actually rather natural for the front tyres to wear out faster on a front wheel drive car – some of you throttle happy people may be wheel-spinning a little if you’re at the front of the queue at the traffic lights. The front tyres have to handle more work than the rear tyres in a front wheel drive car – both steering and acceleration.

But in reality, even if the front is more worn out than the rear, the correct thing to do is the put your less worn out rear tyres at the front axle and put new tyres at the rear axle – if you only want to change a pair of tyres and not all four. Of course, it’s always better to change all four.

This is because when the front has more grip than the rear, the rear will lose traction before the front of the vehicle during a corner on a wet or slippery road. You will oversteer and fishtail because of hydroplaning. As you know, once the rear starts sliding its quite hard to recover unless you’re a very experienced driver. It’s also better for the driver who has been used to more grip at the rear than the front all this while before the tyre change to get used to the new grip levels if you put the new tyres at the rear.

If the front tyres hydroplane, it is easier to correct than if the rear tyres hydroplane because what will happen is understeer, and understeer can be corrected relatively easier by easing off the throttle.

So be safe – always ensure the rear tyres have better or equal grip. For even tyre wearing, it’s recommended you rotate your tyres, but that’s a story for another time.

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.

Let’s ignore how turbochargers work and just assume it works since this post is not about turbochargers. The engine receives the turbocharged air through the intake. That’s assuming the throttle is open. Now what happens when you lift your foot off the pedal? The compressed turbocharged air has no where to go. It hits the closed throttle plate and goes back up the intake manifold the opposite direction. Back into the turbine. This high pressure air hitting the turbine blades from the wrong side of the turbo slows down the spinning turbine, thus reducing boost. When you press the accelerator pedal again, the turbo has to slowly spin up again to gain maximum boost. This is bad. Very bad. The reverse surge of turbocharged air could also damage the turbine. This is also bad. Very bad.

Air is released. Pardon the noobness of the diagram!

This is why blow off valves exist. It releases turbocharged air coming down the wrong direction of the intake manifold out to the atmosphere. You get longer turbocharger life, quicker spool, and better transient response. Of course, there is the issue of the stock standard ECU expecting air but not getting air, and pumping too much fuel in, but that’s a different issue. For cars with that problem (usually because of the usage of Mass Airflow Sensors) there is a different type of blow off valve that recirculates turbocharged air back into the intake instead of releasing it into the atmosphere. Sounds a lot less cooler though heheh.

Recirculating blow-off valves send air back into the intake

You can’t put a blow off valve on a naturally aspirated car because induction (the sucking of air into the engine) is done using vacuum. The engine itself sucks air in, instead of the turbine pushing compressed air in. When the throttle is closed, no air is being sucked in, and there is no boost bouncing back into a non-existent turbocharger turbine. There is nothing to “blow off”.

So that’s what blow off valves are for, and that is why you only put them on turbocharged cars. So if you want that cool sound that turbocharged cars have whenever they shift gears, you need a turbocharged car. Like a Perdana V6 Twin Turbo.

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.

Contrary to popular believe, NOS isnt the chemical acronym for nitrous oxide. It is actually the acronym for Nitrous Oxide Systems, the largest manufacturer of automotive nitrous oxide injection systems out there. Its become so synonymous with the gas, like how Maggi is associated with instant noodles, Colgate is associated with toothpaste, or Nescafe with instant coffee, or how making a photocopy of something is called Xerox-ing. Nitrous oxides chemical designator is actually N2O, because it has 2 nitrogen atoms and 1 oxygen atom.

Lets find out more about nitrous oxide injection systems.

What is Nitrous Oxide?

The usage of Nitrous Oxide to enhance engine performance dates way back to World War II where N2O was used in fighter planes to compensate for less oxygen in the atmosphere at high altitudes. One of the first uses of nitrous oxide in cars was by NASCAR racer Smokey Yunick who used nitrous oxide in his car to win races until it was discovered and banned by NASCAR.

Nitrous oxide is color-less and non-flammable. Apparently it smells somewhat sweet. Dentists use nitrous oxide to as anesthetic for patients, and its known as laughing gas in the dentistry circles. Its stored in the vehicle in liquid form in a canister. Because of limited storage capacity, usually limited “shots” of nitrous oxide is stored and the driver uses it sparingly in bursts by activating a button. Like what you see in The Fast and the Furious.

How does Nitrous Oxide work?

So how exactly does injecting nitrous oxide into the engine help? Combustion is basically igniting a mixture of oxygen and fuel in a combustion chamber with a sparkplug. The resulting explosion produces power. What happens is a nitrous oxide injection system pumps nitrous oxide into an engines intake system. At 296 degrees Celsius, the nitrous oxide breaks down into nitrogen and oxygen. The loose oxygen atom is burned together with the combustion. More oxygen = more power. Its as simple as that.

Of course there are some issues with the proportion of fuel and air and pre-mature detonation that well look at later. Also, why not just inject oxygen instead of nitrous oxide since what we need is the oxygen anyway? Pure oxygen would result in too wild a combustion, resulting in a blown engine. This is because the nitrogen atoms in the nitrous oxide have a function as well. The nitrogen atoms released have a cooling effect on the combustion temperature. It absorbs the heat and helps carry it away.

Nitrous oxide also cools the intake temperature by 60 to 75 degrees Fahrenheit and every 10 degrees Fahrenheit reduction in temperature gives you about 1% horsepower gains. So on top of the extra power provided by the extra oxygen, you get another 6-7% horsepower gains from the cooling effect. In one of the Sepang Drag Battle rounds, the winning Proton Satria used nitrous oxide to cool the intake air instead of an intercooler. That way, you save weight and reduce the lag that you get when you have to pass turbocharged air through the passages inside an intercooler.

Nitrous oxide storage tank in a car boot

Those who are more familiar with nitrous oxide would have heard the terms dry kit and wet kit. What is the difference between nitrous oxide dry injection and nitrous oxide wet injection kits?

Nitrous Oxide Dry Injection Kits

Nitrous oxide dry injection kits spray nitrous oxide into the intake manifold and it is mixed with fuel and air at the injectors. Dry shots of nitrous oxide usually provide less of a power increase because there is no way of providing additional fuel to balance the extra oxygen in the combustion mixture. So you have to be a little conservative as too lean of an air-fuel mixture will cause the engine to just blow up. At least with stock factory injectors anyway.

Nitrous Oxide Wet Injection Kits

The other type of nitrous oxide injection is wet nitrous oxide injection. Wet nitrous oxide shots have fuel in them. This explains the usage of the word wet. The nitrous oxide is mixed together with fuel and a fogger injects this mixture directly into the throttle body. This provides the extra fuel to balance out the extra oxygen provided by the nitrous oxide, thus keeping the air-fuel mixture stoichiometric or not too lean. However wet nitrous injection kits might cause puddles of fuel to be stuck in the intake manifold, and cause severe backfire conditions.

There is also a hardcore form of wet nitrous shots called direct-port injection. In this system, each cylinder gets its own nitrous injector. For this modification, the whole intake manifold has to be removed and fitted with a custom one.

Is Nitrous Oxide Safe?

With the increased power being created, how does one control the process so that no engine blown cases will happen? Using wet nitrous shot kits is one way, as it mixes the additional fuel necessary to keep the air-fuel mixture balanced. Ignition controllers are also sometimes installed to retard the spark timing when nitrous oxide is being used, to prevent premature detonation, also known as knocking or pinging. Higher octane fuel should also be used.

Balancing the air-fuel mixture with the extra oxygen provided by nitrous oxide is also a tricky thing. Too lean and youll get detonation problems which will damage the engine. Too rich and youll lose power. But its all fun, tuning your car to the maximum performance. Good learning process.

To end this post on nitrous oxide, let’s have a look at how nitrous oxide can breath new life (and power) into your engine! Enjoy this video clip by Top Gear, where they kit up an old Jaguar with nitrous oxide and pitch it against some newer supercars.

Digg this article!

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.

The reason for this is poor quality control by Proton assemblers. The alignment of the door hinge is not aligned properly. Here is the solution.

You can click the images for a bigger version.

If you look at the photos, you can see the marking lines on the lock does not line up with the marking lines on the door.

What you need to do is take a screwdriver, loosen the screw and realign the lock. You don’t have to unscrew it, just loosen it so you can reposition it.

Here is the result… the proper alignment of the door lock. Now your Proton Gen2’s doors should be able to open and close with ease.

Original Thread: Cari Chinese Forums

Thanks to Kah Soon for the pointer and translation.

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.

Cars like the Mclaren F1 uses the material all over the car, including the unibody. Other supercars like Pagani Zonda, Enzo Ferrari and Porsche Carrera GT also apply the material to it’s cars.

The BMW M cars use carbon fibre roofs, where layers of carbon fibre are placed in a 1,800 ton press and moulded into a roof that is half the weight of an equivalent steel roof. Having a light roof not only saves weight but lowers the car’s center of gravity. It’s also great to look at.

The Satria R3 uses carbon fibre here and there in the car. I can only recall the spoiler, gear knob and spark plug cover.

The applications of carbon fibre in the automotive world makes even the mention of the word ooze with luxury and performance appeal. It’s also found it’s place in laptops, naturally because it is lighter.

You have to admit it. Carbon fibre is turning into a fashion statement!

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.

The cams are driven by the crankshaft, using either a belt or chain called a timing belt or timing chain. If the timing belt/chain snaps and the camshaft stops spinning, the piston coming back up the combustion chamber might hit the open valves. This is very costly. That’s why you should always change your timing belt/chain at the interval specified by your car manufacturer.

SOHC refers to Single Overhead Camshaft. In the days before DOHC, it was known as OHC, with no need to differentiate between a single or double camshaft. In SOHC, the camshaft is situated in the cylinder head, above the valves. The valves are opened and closed either directly with a shim between the cam lobe and the valve stem, or via a rocker arm. SOHC engine valve configurations typically have 2 or 3 valves per cylinder. It is also possible to have 4 valves per cylinder using SOHC but this translates into a complicated combination of rocker arms and cam lobe shapes. An example would be the 4G92P in my car which is a SOHC but has 4 valves per cylinder.

DOHC refers to Double Overhead Camshaft. This arrangement uses two camshafts in each cylinder head. Two cams per cylinder head means that a DOHC V engine has 4 camshafts because it has 2 banks of cylinder heads. This allows the manufacturer to easily implement a 4 valve per cylinder setup. Most of the time it also allows the engine to rev higher. It also allows better placement of the valves in an optimized setup that gives you maximum performance. But the disadvantage of such a setup is more weight, more cost and more complexity. It takes more stuff to drive two camshafts. The main reason to use DOHC is to drive more valves per cylinder. If a SOHC setup can allow 4 valves per cylinder, having a DOHC engine will not bring that much benefits over SOHC and the additional weight becomes a burden instead. DOHC engines also allows the spark plug to be placed right in the middle of the combustion chamber. This promotes efficient combustion. With SOHC, the camshaft is usually in the middle of the head because it has to drive both the intake and exhaust valves, robbing the sparkplug of it’s optimal location.

In the end, a SOHC 16 valve engine would have better torque on the low end where the DOHC valvetrain’s weight results in lower torque. But at high engine speeds, the 16 valve DOHC engine’s peak torque and horsepower would be greater. That’s the trade-off. With the amount of valves being equal, SOHC has better low-end torque because the valvetrain package is lighter while DOHC has better top-end power.

Other benefits of DOHC would be making it easier to implement variable valve timing technologies (which I will cover in another blog post) and also you can tweak it better with adjustable cam pulleys. If you were to put high-profile cams in your DOHC engine, the cam lobe profile can also be more optimized than a SOHC engine because you can play around with the lobe shape easier with separate camshafts for the intake and exhaust valves.

Why more valves per cylinder? Why not just make 1 huge intake valve and 1 huge exhaust valve? Bigger valves weigh more than the smaller one, so controlling the extra weight as it gets flung open and close becomes difficult. The spring has to be stiffer. A stiffer spring means more energy has to be spent overcoming the valve pressure. This partially oversets the gains which a bigger valve has to offer. Another problem with a single big valve is at lower RPMs the intake velocity will be lower. I’m sure you guys know this… the same amount of air going through a big pipe will have lower pressure than the same air going through a smaller opening. Think of how you can control the water pressure of your garden hose by adjusting the opening size with your finger. Because of the velocity drop, low RPM torque and driveability will suffer. Although two smaller valves weigh the same as 1 big valve, and with the extra rocker arms and springs they can actually end up weighing more, this is offset by less mass to be overcome when opening and closing the valves.

So, are more valves per cylinder really that beneficial? Here’s comparing a Nissan VG30E to a VG30DE. Both are 3 liter electronic fuel injection engines, but one is a SOHC with 2 valves per cylinder and the other is DOHC with 4 valves per cylinder.

We can see that torque at low RPMs are about the same for both engines, but at higher speeds the 2-valve per cylinder engine has reached it’s peak and has to switch to the next gear while the twincam 4 valve per cylinder engine continues making more power at the top-end of the powerband. The powerband is also longer. (Note: I’ve added this graph here to show you the difference between 2-valve and 4-valves, not SOHC vs DOHC. Couldn’t find any graphs for SOHC vs DOHC. Sorry!)

So to sum it all up, SOHC has better low-end power, DOHC has better high-end power and overall maximum power. 4 valves per cylinder is much better than 2 valves per cylinder and it doesn’t matter whether 4-valves is achieved via SOHC or DOHC.

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.

Our local car manufacturers have begun equipping their higher end models with ABS. What is ABS? I know some of you think ABS stands for Air Bag System. No, it doesn’t okay. Heheh ABS stands for Anti-lock Braking System. What is ABS? Let me explain how it works and what is the proper way to use them.

Most of us have been taught that during heavy braking such as emergency braking to avoid an accident, you have to pump the brakes on and off to prevent skidding due to loss of grip when you brake too fast. When you slam on the brakes hard on a car without ABS, the wheels will jam, especially if you have crappy tyres. Once the wheels are skidding you have loss of car steering control because the wheels do not grip the road, and no matter what amount of steering you do, the car will continue moving in the direction it’s inertia is bringing it. Thus, the pumping action we have been taught to do during heavy braking. It involves stepping on the brakes then releasing them when they lock up and doing it repeatedly so that the wheels do not remain locked.

However because of this mindset of braking without ABS technique that we are used to, most of the time ABS causes more accidents than it prevents.

How does ABS work? In a car with an ABS system, there are sensors to measure each wheel’s rotation speed. Under heavy braking, if the sensors detect that any of the wheel’s rotation speed is about to lock, it will send a signal to a computer telling the brakes to relieve braking pressure on that wheel to prevent it from locking. This computerized brake pumping action can happen up to 15 times per second. The result is a smooth and steady slowdown to a halt, shorter braking distance and maintaining steering control during heavy braking.

The proper way to brake during ABS is just to slam on the brakes hard and keep your feet stepping hard. If the ABS is working, you will feel your brake pedals vibrating and making some noise. Alot of people misunderpret this feeling and take their feet off the brakes instead of keeping it slammed down. This is what causes some of the ABS-related accidents. Do not panic if you feel the vibrations, and do not let go of the brake pedals! When braking the proper way, you will find that your wheels will not lock and you still maintain excellent steering control over your vehicle so you can steer yourself around the obstacle that you have to avoid.

Remember that there is only a difference in braking technique between ABS brakes and normal brakes during emergency braking situations. Normal braking situations like slowing down before a speed bump should be done as usual. ABS also does not activate below a certain speed limit. ABS works best on wet road conditions because it is more likely for wheels with normal brakes to lock on wet surfaces. You can really feel the difference.

So remember, in emergency braking situations, never pump your ABS brakes. Learn how to get used to how it works and how it feels. Go to some deserted parking lot or something and practice. It will let you familiarize yourself with how your ABS will feel under heavy braking situations and you can train yourself to maintain control over the car during such situations.

Oh yes, ABS brakes primary function is to allow you to maintain steering control over the vehicle while under heavy braking. Don’t use it as an excuse to brake very very late and tail people closely.

© 2009 Paul Tan's Automotive News. All Rights Reserved.

This story originally appeared on Paul Tan's Automotive News on Sun, 22 Nov 09 15:43:30 +0800.