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Thread: some modern technology in cars explained

  1. #1
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    Default some modern technology in cars explained

    hello every one.i am starting this thread to explain to the forum users some of the modern and recent technology trends and terms that are being brought to india by foreign companies or are being adopted by our indian based companies on their latest cars.

    i will try to explain in very simple terms and please do feel free to ask,or better still google the topic for better knowledge.

    what is torque?

    torque is the turning force of an engine.more torque it translates to better acceleration of a car from "any" gear.

    an example of torque-try closing a door holding it at its edge and at its hinges.it will be more difficult to close it holding at its hinge than at its edge.this is more torque.


    diesel engine is better than petrol engine,but why?

    a diesel engine runs at more compression ratio than a petrol engine,as a result gives more bang for a specified amount of fuel,leading to more efficiency which translates to more milage.

    then why not always use diesel engine?

    because of that more compression ration,the wear and tear is very high,noise is higher and weight of the engine is also more.



    petrol is classified by octane number but what is it?

    it is the percentage of iso-octane(a compound) present in petrol.

    so more octane number means what?

    octane compound can dramatically increase the ignition temperature of petrol.which means that the fuel can be compressed to very high ratios before it is ready for combustion.

    octane number for petrol so what for diesel?

    it is classified by cetane number.it is a measure of time difference between ignition and start of combustion.



    what is MPFI?

    it stands for multiple point fuel injection.it is used in petrol engines for injecting fuel at a very high pressure into the cylinder.high pressure translates to better mixing of the fuel with air and better burning of fuel.now a days almost all petrol engines have MPFI which have replaced an older technology called carburator which used atmospheric pressure to direct fuel into the cylinder.

    what is CRDI?

    it stands for common rail direct injection.it is similar to petrol injection.a thin cylindrical metal pipe contains diesel at very high pressure.this fuel is injected to the cylinder directly.



    what is turbo charging,and why is it used?

    the more air is put into an engine cylinder,the more will be the amount of oxygen present for combustion and better will be the burning quality of the fuel,which translates to more power.

    an engine produces exhaust gases which has some energy,which is pressure energy.it is used to run a device called turbine.the turbine runs a compressor
    which compresses air and directly puts this compressed air into the cylinder for combustion.thus for free or at no extra cost(,air has been compressed and more power has been extracted .however a term called "back-pressure resistance" comes account for turbo charging but lets that leave it for another day.

    turbocharging has some downside called turbo lag.what is it?

    if a car is running at low speeds and engine speed is very low or the car is accelerating from low speed,obviously the fuel burnt will be also very low which leads to lower exhaust volume and lower exhaust pressure.as a result the turbine speed will be very low and compressor will not compress enough air to be feed to the engine.here comes a brilliant idea named "VGT" used in cars like hyundai verna and suzuki swift VDI.

    VGT stands for variable geometry turbo.it is nothing but a simple modification to the turbine.the problem was low exhaust pressure couldn't run the turbine fast enough.now variable geometry means that the turbine blade's angle to the inlet exhaust gas can be changed according to volume of gas available,which means that even if the exhaust pressure is low the turbine speed will not be affected and will run at constant speed.

    thus a VGT changes the blade angle of the turbine automatically leading to constant speed of the turbine and compressor which leads to minimal turbo lag.


    what is a better alternative to turbo charging,the VGT makes it very complicated.

    solution is super charging.it takes power directly from the engine crank shaft to run its turbines,hence no turbo lag.only downside is that this is not free,it consumes some amount of engine power for its operation.




    what is Hybrid technology?

    when a car is braking,it looses speed,all the energy that has been used to bring that car up to that speed gets wasted and is converted to heat energy in the brakes.so how to use this energy?

    solution is connect the drive shaft of the car to a generator or dynamo,which produces electrical energy.this electrical energy is used to charge batteries.the power from the battery can be used to run a motor which in turn can propel the car in a stop go traffic and the engine can remain OFF.

    an example of hybrid system is KERS or kinetic energy recovery system,which does the same thing as other hybrid cars


    what is power steering?

    it works on the principle of a car jack.less effort can be used to move or lift heavy object.it is either hydraulic or mechanical.in layman's terms try to imagine the steering of the vehicle as the handle of a jack.thus very less effort is being used to steer the wheels of a very heavy vehicle.


    what is ABS?

    it stands for anti lock braking system.it prevents wheels of a car against lock up when braking

    but why use it?

    if the front wheel of a car gets locked up at high speed,it stops taking input from the steering as a result becomes unsteerable.if some how the front wheels can be prevented from locking up at high speed braking,accidents can be prevented.

    but how is it done?

    interconnected RPM sensors or tachometer are installed in all the wheels and they are connected to the braking system of the car.what the RPM sensor does is it compares the speed of all the wheel when braking,if a particular wheel sensor registers lower speed then the other sensors,it means the wheel is skidding and automatically the brake caliper loosens up on the disc or drum and this way it prevents locking up.

    a modification of ABS-it's called TRACTION CONTROL often heard when discussing powerful sports cars or supecars.
    in rear wheel drive powerful cars the rear wheel tends to spin without moving the car forward when starting from stop or on pressing the accelerator to hard.it may look spectacular but it is nothing but a waste of power and it is a complete no no in racing industry.
    so came principle of ABS is used to prevent wheel spin.RPM sensors monitor the speeds of wheels and if a sensor registers more speed,immediately power is cut off.

    what is cruise control?

    it can be used to control the speed of the car by adjusting the throttle position.
    take for example on long highway drives,the driver has to continuously keep his foot on the accelerator pedal,in cruise control,the driver sets a constant speed and the control system automatically sets the throttle position without the driver setting foot on the accelerator pedal.



    what is catalytic converter?

    it is an device which reduces the amount of harmful hydrocarbon and gases present in the exhaust of an engine.it is generally located under the car in the exhaust pipe and looks like an expansion chamber.


    how is it done?

    it is more of chemistry than anything to do with automobile engineering.a catalyst named platinum oxidises the complex compound (carbon mon oxide and nitrogen oxide compounds) to simpler compounds.

    the catalytic converter is larger is size than the rest of the exhaust pipe because more the area more is the contact of the gas with the catalyst and better will be the oxidation of harmful gases.


    how does an airbag senses that the car has collided or crashed?

    an instrument named accelerometer does the trick.it is a device which can sense G forces or acceleration or deceleration for that matter and deploys the airbag.

    how an accelerometer works?

    it can be mechanical,piezoelectric or capacitive.google them to know more.



    what is drive by wire technology?

    it is a term used only with premium cars.it is a technology directly taken from aircraft engineering.drive by wire means there is no mechanical linkage between the input system and the output system.

    an example-in older cars pressing of the accelerator pedal directly opened or closed the throttle giving power.but in a modern car this sytem will be like this-the accelerator pedal will be connected to an electronic position sensor which in turn will open or close the throttle.this gives better control of the throttle position and thus better control.

    why is there a wing on a modern Formula 1 car?

    a wing does the job of providing mechanical grip or downforce to the car when it is in a high speed bend.

    mechanical grip means the front wheel of the car is able to turn the car without skidding.

    so how does the wing work?

    it works on the principle of an airplane wing.in airplane it produces lift.

    if we can some how reduce the pressure on the top surface of the wing than the bottom surface,lift can be achieved.

    so how do it?

    the top surface leading edge is more curved than the bottom surface,which makes the air flow faster than the bottom surface.more speed of air leads to lesser pressure,and thus lift is achieved.

    in F1 cars this wing is inverted an it produces mechanical downforce which prevents the cars from taking off the ground at high speed cornering.


    we have heard of bajaj motorcycle company making huge claims about their DTSI technology,if it is so good,why not premium cars and racing cars use them?

    DTSI isn't a groung breaking technology,better technology are available.it is called MSD or multiple spark discharge technology.what it does is it produces multiple sparks at the time of the ignition at over a varied period of time leading to better combustion of fuel mix.



    right now at this point of time nothing much is coming into my mind so i will update this topic later to add more newer stuff.


    note-i may not be correct in every topic,so please do correct me if i am wrong and do add your inputs as well.


    cheers.
    CUSTOM MACHINED

  2. #2
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    Nice info there...knew it though...if you have copied it from somewhere, please do tell the source

  3. #3
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    does it look like a cut and paste job
    seriously man if u need more info on these stuff visit howstuffworks and wikipedia,everything is there from basic to advanced.
    CUSTOM MACHINED

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    Nice job. But very poor readability.

    I suggest that:

    - you use capital letters
    - prefix questions with a Qn and answers with An
    - do not add extra para break between Q and A
    *** Never argue with an idiot. ***

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    thank you just4kix for the appreciation.
    well this was my first,so i will definitely take your advice from now on.
    cheers.
    CUSTOM MACHINED

  6. #6
    Guardian Angel just4kix's Avatar
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    Quote Originally Posted by iorhld View Post
    thank you just4kix for the appreciation.
    well this was my first,so i will definitely take your advice from now on.
    cheers.
    Rep+ to you. Looking forward to more tech articles.
    *** Never argue with an idiot. ***

    All my useful articles and Guides | My DVDs | My Blu-Rays | My Blogs
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