Saturday, October 27, 2007

Making your Automatic car dance to your tune

The most common complaint and comment about an Automatic tranmission car, is that “You have less control over it, there is less involvement, compared to a manual transmission car”. Agreed, you can’t dictate the car to change to any gear that you please when you have an automatic transmission, but from my experience, I can tell you, if you know your know your car well enough, and if you are able to feel what it is doing, you can make even an automatic transmission car do whatever you please (well almost!).

First of all it’s possible due to the fact that most engine management system of today’s cars are intelligent and are based on a feedback system. The car does n’t just do pre-programmed actions irrespective of anything anymore, but on the contrary, listens to the driver input, tries to gauge the intention of the driver and tries to act accordingly, producing wonderful results almost always.

Next is your talent, how much you know your car and can undestand what it’s trying to tell you.

Downshifting in an Automatic car

Apart from the obvious manual change to”L” or “2″, the modern day cars downshift when you floor the throttle (full(open) throttle), provided the current revs of the engine can accomodate a higher rev as a result of a downshift. Imagine, you are cruising along at a rather relaxing speed of 70 km/hr in Overdrive(highest gear), when you need to pass a lorry in front of you, and an intersection is approaching, so it’s a case of now or never. But since you are in Overdrive, obviously you may not have enough acceleration to complete the overtaking manoeuvre before the intersection. No probs! You just floor the throttle, the car immediately shifts down to the previous(lower) gear, u get a jolt of acceleration, the next thing you know is you have passed the lorry at a speed of 90 km/hr. No more waiting for the speed to build up and no more nervous times during a pass

Warning: Do not ease the throttle(i.e., always keep it in full throttle) in the middle of the overtaking manoeuvre or else the car will upshift and lose acceleration and phew! you don’t want that to happen. So keep it floored till you have completed the overtaking.

Upshifting in an Automatic car

Now it’s not as straightforward as the downshift because here you have got to do all the work. The secret lies in judging if the rev (engine speed) is appropriate for an upshift and playing with the throttle. Generally, an automatic car upshifts to a higher gear in the start-middle of the rev band appropriate to the next higher gear. But sometimes we need power. So to prevent an upshift untill all the revs (max revs) at the current gear is utilised and you get maximum acceleration, floor the throttle and don’t ease it until it upshifts. But sometimes at higher speeds, not letting the car upshift will sometimes keep you in a low speed gear when you want speed and not torque. For that, just ease the throttle when you want an upshift. The engine management system(EMS) senses that since you are no longer in full throttle, you don’t the need the acceleration and torque and can upshift. Once it has shifted up, you can get back on the throttle (but not full throttle, else it might downshift again), and drive away. The beauty here is you can upshift almosy whenever you want to (i.e., at whatever rev you want to) by easing the throttle. But there is a limit to it. You can use this easing the throttle to upshift only when you are in the right rev band. If you ease the throttle too early (before the rev band of the next higher gear), the car will not upshift and you will just slow down, and if you don’t ease the throttle at all, it might not shift untill it hits the red line which might be unnecessary sometimes. It’s a delecate balance between speed and torque, and it’s a wonderful feeling when you get it just right.

When the driver sensitive EMS of the car, and your feel for the car work in tandom, you can make it dance to your tunes. It’s sometimes more challenging than a manual car because, there are no explicit levers to do anything, you are just overriding the car by thinking from it’s perspective.

My Vrrrooom Come True !!

Imagine, you are in love with a girl for 17 years, and one fine day, she accepts your love. That was the exact feeling I had when on Sunday, August 19, 2007, I went to a quiet residential area in Cholaimedu, got down from the taxi, shook hands with my “wizard”, and walked a few paces to see, my new love, my sparkling new “Passion Red” Hyundai Santro Xing XL Automatic, modified with hand operated controls, so that atlast after 17 years of gazing at, thinking about, breathing, eating and sleeping cars, I could not only own, but drive one. The one month long sleepless wait after I ordered the car is over! Phew! Hurrah!!

First the “wizard” proceeded to drive the car, to show me how the new controls work. Of course, I knew how it worked, having read about it in websites, it’s called the Alfred Bekker System. I loved cars so much that I had a massive and detailed knowledge about how a car works, the dynamics, the mechanical details, and of course, about the nuances of driving a car, the only thing left was to get in and drive, and get used to the behaviour of the car. Since, it was a residential area, he could n’t let me drive much, which I was furious about by the way. I didn’t come all this way to be a passenger in my car!. So he let me drive about 100 meters. Sat in, shifted the tranmission into “[D]rive” mode, and drove, was careful, not to get carried away though. The power steering was very light and agile but lacked feel. But, at once I felt comfortable with the controls and just as I had imagined, was confident that I could master the car in a matter of hours. This was my first ever time in the driver’s seat of a car!

A driver drove and brought the car back home, although I drove another 300 yards while approaching my home. Gazed at the parked car, and retired for the night.

The next morning, I drove the car to a ground, with my mom and dad(who also had never driven a car before), and started to put the car through it’s paces, to get a feel of the steering, throttle etc. I drove for about 30 min, driving through a virtual circuit, making turns and straights to get the feel of the car, then my dad took the wheels, and drove another 30 min, then we hit the road, drove slowly (at 10-20 km/hr!) around the houses, another 30 min-30 min session. After lunch, I felt really confident and I was in the groove, I started to effortlessly maneuver the car along the twisty bends and was taking corners with increasing confidence. Now, I was no longer feathering the throttle, it was full throttle time and hit 80 km/hr near a small straight piece of road near the beach, he he but immediately reduced the speed as my dad started to stare at the speedometer from the pillion seat coz we are not supposed to drive it @ more than 70 km/hr, in the run-in period of the car

My real dream come true came when on Saturday (6 days after I got my hands on my baby), I got a chance to go to Chennai, what an absolutely unforgettable experience, I got to drive on the beautiful ECR, for about 100 km, still I had to back off the throttle as it was still run-in period. But this Saturday, I got a chance to drive to Chennai again, this time around, the car was out of the run-in period, and so was I, he he. The open road!, a beautiful, peppy little car!, what more do I need? So when I got a chance on an empty stretch, I caned it and reached a speed of 125 km/hr. What an absolutely wonderful feeling to see the speedo in front of you, at that time! But don’t be under the impression that my driving is haywire. I am a perfectionist, be it the driving technique or the following the traffic rules, and total control is my mantra.:)

I have driven many of friends in my car, it is really a dream come true to drive them in my car, because, they have taken me in their cycles, and shoulders when I needed it.

By the way, last but not the least, the “wizard” who made my dream come true is:

Mr. Bhaskaran

NO 25, NEW MARKET STREET,
CHOOLAIMEDU,
CHENNAI - 600094

Mobile: 9841190690

To mention a few words about him, he is an obviously talented Automobile Engineer cum car modifier, who specialises in modifying cars for physically challenged people. He has modified more than 150 cars so far, with 100% success and satisfaction, including the top- guns like Mercedes Benz, using the Alfred Bekker system. For under just Rs 19,000 (this might be variable depending upon the car), he had fabricated and fitted custom built hand operated kit for the accelerator and brake and combined both into a single lever, which operates both, mutually exclusively, using a push-pull mechanism, which makes it fool proof. The whole process takes just about 4-6 days. As a client, I could not be any more happier with him, both as a car modifier and as a person. His work is impeccable, his manners, immaculate. He is a boon for physically handicapped people, atleast through out Tamil Nadu. He is a rare breed indeed, because, although there are many car modifiers in Chennai, finding such a car modifier for physically challenged people in Chennai, is like finding a pearl in a haystack. (Ya he is a Pearl!).

She is My McLaren

She is My McLaren

She is very haughty
yet soft inside
the more challenging, the more interesting
but very hard to handle
You have to be on the toes
Like a McLaren F1
But once you get acqainted its fun
A wonderful experience
But if u lose control at 375 km/hr
You are dead
Cannot rev the engine up initially
she will cause wheel spin
But she gets into the groove
then she is really smooth
But as a driver u have got to be very skilled
Demanding indeed but worth it and full filling
But very expensive
Really a driver’s car
She is my McLaren..
And, I will not lose her for anything else..

- Ragesh

The physics behind the pandemonium of driving cars

You watch a Grand Prix on a Sunday evening, and your mother exclaims, "What pleasure could you possibly derive from watching the same cars go round and round the same track for 2 hours?".

But there are plenty of things to learn as we watch the cars go by. In fact even without watching it, just a little contemplation on your side is enough to understand the nuances of the dynamics of a vehicle as it goes through sweeping corners at break-neck speeds.

What you see in Grand Prix can be applied in real-life situations. Contrary to popular belief, Grand Prix races do not encourage perilous driving styles. In fact they encourage you to drive safer, better and more efficiently, being cogniscent of what your vehicle is doing.

The secret of the tyres

The silken smooth tyres of the Grand Prix cars and bikes might give an impression that they are very slippery but it's not so. The friction produced between the tyre and the road is directly proportional to the area of contact, hence the smoother and flatter the tyre, the better the grip. This is because when two very smooth surfaces come into contact, the distance between them is so small that it is comparable to atomic distances and hence nuclear strong forces take over (The same reason you feel grip when you run your finger on a marble floor).

This theory has an exception though, during rains. Then if you use a slick (smooth) tyre, the water that is trapped between the tyre and the tarmac does not have any place to go and formes a layer of accumulated water between the tyre and the road, causing a phenomenon called "Aquaplaning" or "Hydroplaning", in which the grip reduces drastically and you feel as if your car is skating on ice. Hence during rainy days, it is advisable to change to a tyre that has deep treads that have channels to push away the accumulated water through sides.

Going around corners

Ever thought why the Grand Prix cars seem to be weaving around the track, changing lanes, sticking to a specific line every time? There is a beautiful science behind it. In fact it is very useful in day today life. I use it often. But you must stay within your lane. Every corner has a specific line which will provide you the fastest way around it, called the "Groove" or the "Racing line".

The simple theory behind it is the less steering input you give, the faster your vehicle can travel, and the more stable it will be. That is because when you turn the wheels, especially the back wheels are not exactly pointing in the direction the car actually goes. Hence every moment the back wheels point along the line of the tangent to the curve that you are describing. Hence there is a constant force or acceleration applied to the vehicle. A component of the force produced by the wheels is expended in over coming the frictional force. Hence the lesser force you have along the direction of the motion of the car.

So the best way to approach a corner is : Enter from the outside, cut through the inside (apex) of the corner and exit through the outside of the corner, as shown in the picture. Our aim is to describe an arc that has the least curvature or most radius of curvature and the least circumference as possible. Also this method puts less stress on your tyres, and less g - force on you, hence, longer life for the tyres and smoother ride for you.

Cutting the apex of the corner

If you follow the inside line through out, then you have to brake and reduce the speed, hence you use more time.

If you follow the outside line, still the curvature is high and the circumference too is high, hence reduced speed, longer distance, hence more time wasted.

The secret is not to perceive the road as a whole and blindly trying to go parallel to the edges of the road. The secret lies in being able to see the straightest path between two points. The curves in the road need not bother you. Why go in a zig-zag way around a series of corners if you can find the straightest path between them.

As the followig diagram depicts, though the road seems to be winding in a zig-zag way, there is a fairly straight path through the series of curves.

Driving Line

The slip-stream

Now, why do Grand Prix cars pull up behind the car in front and sling shot their way past to over take? It is not any ambushing strategy. But it the exploitation of a beautiful phenomenon in fluid dynamics.

When a vehicle moves at speed, it creates turbulence in the air. And the turbulent air tends to stick to the vehicle more. The less aerodynamic the vehicle, the more the turbulence. Now due to this air behind a vehicle is moving and hence when you drive behind it, the relative velocity of the air in front of you w.r.t to you is less. Also since the vehicle in front drags some air with it, there is a low pressure created in its wake. Hence, for you the effect is low drag, and low drag means lesser energy to cut through the air. Hence with the same amount of energy, you can travel faster, travel at the same speed with less amount of energy. Hence you drive more economically. Now this a strategy I use in the high ways. But again be careful, do not go too close to the vehicle in front.

Thus with the help of physics, we can exploit the most out of our cars' performance. Nature hides many secrets for us to exploit. It is up to science to find it out and explain it and it is up to us to use them to our benefit. I have tried to be as simple and basic as possible. Happy Driving!!

Note: I should clear some things out. When I say cut the corner, I mean in a one way highway with medians (like Old Mahabalipuram road), when u apply the same technique to a two way road like the E.C.R, read road as "lane". Anyway the techniques are going to be the same, only that you are going to stick to your lane.

So the 2 figures will now look like this :
apex1.JPG

and this:
line1.JPG
Just a little bit of adaptation :).

Klues 2 Klueless 2. Don’t be Klueless anymore..

With Klueless 2, spreading like wild fire, let me share my knowledge with you guys, hope these Klues will help you win Klueless 2.

Level 1: Know the anatomy of the eye well and know a bit about Klueless 2.

Level 2: Come on, He is THE Man we are talking about

Level 3: What do u see on the screen, any relevance with our man

Level 4: Look at the Title, read the note carefully, who has written it. Link all of them. Remember this is Klueless. So you gotta think out of the box.
Level 5: Look at the plate, be proud of Indian Mathematicians.

Level 6: Ah too simple, or soo timple rather.

Level 7: Break the crust n see what do u get, who is the creator of that.

Level 8: Vrrrrooom!! Automibili irresistable

Level 9: Think ‘laterally’, and you wont be Klueless anymore.
Level 10: Concentrate on the title. Link all of them. It is a very useful item lying around on your desk.

Level 11: Forget philosophy, just look at the words.

Level 12: Don’t get confused with numbers. Think with your right brain.

Level 13: Concentrate on the last line of the story, It is pretty simple, if you get the ‘perspective’ right.

Level 14: Read the lines carefully, use little bit of probability. Then may be search.

Level 15: Come on there is something wrong about it, how do you read it.

Level 16: Concentrate on the position of the cat. Where is it? what is such a place called.

Level 17: Read it the way it is instructed. Look at how it is written

Level 18: What is the winning combination? How is it encoded?

Level 19: Read the story carefully. What could it mean. Spell check!!!
Level 20: Use all the information, esp from the last 10 levels of Klueless2.

Good luck! with Klueless 2 !.