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Thursday, October 16, 2008

How to Drift a Car


Drifting is a driving technique and a motor sport where a car slides at an angle, with its side moving in the direction of the turn.


Things to do Before You Begin Drifting

  1. Set up a cone in the middle of the lot. Drive up on the cone and rip the handbrake in an attempt to do a 180. Practice this until you are no more, and no less than 180 degrees from when you started.
  2. Learn how to countersteer by ripping the handbrake from a speed of 30-40mph (anything less will cause an inadequate amount of momentum to get you around the cone) and trying to control the car to a destination until the car stops.
  3. Increase speed of each of these things until you are comfortable
  4. try to do the 180 cone turn but instead of stopping, hit the gas hard and power out and away from the cone.

Drifting with Rear Wheel Drive and Manual Transmission

  1. Find a car with both rear-wheel-drive and a manual transmission. Ideally it should be a sports car with as close to a 50/50 ratio as possible, and enough power to keep the tires spinning is ideal.
  2. Head to an open area (i.e. an enclosed racetrack) safely free of pedestrians and motorists and police!

Hand brake technique:

  1. Accelerate and shift into a gear with room to rev. Second gear is generally used because it allows the widest variance of speed and is best for harnessing the engine's torque.
  2. Push in the clutch.
  3. Flick the steering wheel to the inside of the turn as if you were going to turn around it. While simultaneously pulling the hand brake.
  4. Immediately out some pressure on the gas pedal, let out the clutch, and steer the car in the direction of the slide, using throttle to control the angle of the drift.

More Throttle will make the car turn more, and also move the car away from the turn center. Less throttle will reduce angle, and allow the car to move towards the inside of the turn more freely. You're drifting!


Clutch Kick technique: Used while you are already moving to increase angle and/or revive wheel spin. While you are drifting, you may feel the car begin to lose its drift angle and power. If this happens, you can kick the clutch to attempt to revive to tires spinning speed. This is similar to powershifting, and you are in essence trying to 'chirp' the tires again and again.

  1. Enter a drift.
  2. while you still have the power put on, kick the clutch pedal in and out a few times as fast as you can until the car is drifting again.
  3. end with your foot off of the pedal.
  4. continue the drift, and when you feel the car begin to lose angle/power try to clutch kick again.


Drifting with Rear Wheel Drive Auto

  1. Find a large, open area.
  2. Accelerate to a speed of 20-30(depending on lot size and room)
  3. Turn the wheel hard and floor it. You should feel the rear end slide around if this is done correctly. Only use full throttle to start the drift, after this you should use proper throttle control to continue through the corner.


Preparing to Drift with a Front Wheel Drive Car

  1. Go to a large, open area.
  2. Pull the handbrake or use the parking brake, riding it out the first time or two to get over your initial fear.
  3. Set up a cone in the middle of the lot.
  4. Drive up to it at speed (between 20 and 30 is desired).
  5. Pull the hand brake and turn toward the cone. Immediately after you feel the back end come around, turn to the opposite direction. This is known as opposite lock.
  6. Repeat the opposite lock at that speed until you can control your car well. Practice this for at least several weeks regularly until it becomes second nature. (Don't do this on roadways. It is dangerous to others and can get you fined.)
  7. Slowly increase speed until you are proficient in a speed you are comfortable with. Get to know that speed--you should never drift above that speed unless you are practicing.
  8. Upgrade. At the same initial speed, flick the steering wheel opposite of the turn and swing it all the way into toward the CONE (not turn, you aren't ready at this stage). As before, when you feel the rear end come around, go to opposite lock.


Drifting with a Front Wheel Drive Car

  1. Approach a turn at a comfortable speed, preferably in mid 2nd gear.
  2. Pull the handbrake while turning into the corner, try not to lock the rear wheels.
  3. You should still have the power on, try not to go less than 1/2 throttle at any time during the drift.

- When you feel the car start to understeer, and lose angle, pul the ebrake harder. - When the car seems to turn too much, give it progressively more throttle, and release the handbrake some. -There is no textbook for drifting. You learn by doing it. -Don't tense up, just feel it.



Accident first aid tips

In the event of an accident




Ensure your own safety and that you do not create additional danger

Do not cross a carriageway. Wear reflective clothing if possible. Do not smoke in cases of chemical or petrol spillage.
Ensure the safety of others

Park well clear of the accident site. Look out for physical dangers (e.g. HAZCHEM - hazardous chemical - symbols, damaged power lines or spilt fuel). Disable the vehicles involved by turning off engines and applying handbrakes.
Warn other road users

Turn your hazard lights on.
Assess the casualties

Are you or any casualty in danger? Is the casualty conscious? Is their airway open and clear? Is the casualty breathing? Is there a pulse?
ABC checks on casualties

* Airways
Tilting the casualty's head back and lifting the chin will 'open their airway'.
* Breathing
Ensure all casualties are breathing and have the ability to carry on breathing. If a casualty is not breathing, apply artificial ventilation by blowing your expelled air into the casualty's lungs.
* Circulation
If the heart has stopped (no pulse) 'chest compressions' can be applied (preferably by a qualified first aider) to force blood through the heart and around the body. They must be combined with artificial ventilation so that the blood is oxygenated (use 15 compressions to 2 breaths ratio). That will keep the body receptive to defibrillation when the emergency service arrives.

Get help

If bystanders are present, get them to phone for an ambulance at once. Otherwise, check on casualties first.
Apply life-saving first aid

Life threatening or serious injuries must be treated swiftly. It is vital that such casualties are treated first. Remember: a casualty who is screaming is less likely to be in danger than a silent or moaning casualty.
Bleeding

Control bleeding by applying direct pressure and, where possible, elevating injured body parts.
Burns

Cool burns by pouring cold water over them for a minimum of 20 minutes or until the casualty no longer complains of pain.
Broken bones

Advise the casualty to sit or lie still, keeping the injured part supported by a blanket or pillow until help arrives.
Give accurate info to the ambulance crew

When you dial 999, the control officer needs to know the exact location, type and seriousness of the accident; the number, sex and approximate age of casualties involved and anything you know about their condition, details of any hazards and whether any casualties are trapped.
Give reassurance & minor first aid treatment

Assure the casualty that help is on its way and remain calm yourself. Treat any minor cuts and bruises.
Treat shock

Anyone hurt in an accident is likely to suffer some degree of shock. Talk to the casualty gently and lay him/her down if necessary. Blood loss and shock display the same symptoms.
Provide warmth

Protect the casualty from cold with a coat or blanket. But it is important not to overheat the casualty so do not apply a hot-water bottle or other source of direct heat.
Consider taking a basic first aid course

Contact your local Red Cross branch for details.

source:http://www.rac.co.uk/


How To Change a Flat Tire

Until the day comes when we are all piloting flying cars (and trust me, the day will come), our cars are stuck with these rubber things called tires. They roll nice and all, but they have a rather nasty problem of sometimes losing air. And without air, they become deflated and virtually useless.


Changing a flat tire is not a very pleasant experience. It seems like your car purposely tries to get a flat tire at the least opportune moments. Like when you are rushing home from work to catch your favorite episode of "Happy Days," for instance. You know, the one where Fonzie rides the killer bull while on vacation in Colorado.

Now, there are some of you who might be lucky and own a car with run-flat tires or a low tire-pressure warning system. If that is the case, you might be able to avoid the icky process. But even if you are a hapless soul, changing a tire doesn't have to be all bad. With knowledge comes power. If you are unsure how to change a tire properly, and you want to know, read on.

*

OK, so you are driving along and all of the sudden you hear a loud bang and the telltale thumping noise of a dead tire. You carefully pull off to the shoulder of the road. Checking to make sure no other motorists are going to run you over, you exit your vehicle and inspect the car. Sure enough, your car's left front tire is completely flat. You are not going to be able to keep driving, so you are going to have to remove it and install your car's spare tire in its place.

Jack up the Car


The first step is to find your car's spare tire, jack and tire iron. The spare tire is almost always located underneath the floor mat in the trunk. Unless, of course, your car doesn't have a trunk. If you own an SUV, minivan or pickup, the spare tire is often mounted on the back of the tailgate or underneath the vehicle itself.

Once you have found the spare tire, remove it from the car. If you have an air pressure gauge handy, you will want to check the spare tire's pressure. If this tire is flat, too, you're in a bit of trouble. But let's just assume you have been keeping tabs on the spare tire's health, and its air pressure is perfect.

The next step will involve removing the flat tire. Make sure that the car is in gear (or in "park" if the car is an automatic) and the emergency brake is set. The car should be parked on a flat piece of pavement. Do not attempt to change a flat if the car is on a slope or if it is sitting on dirt. It's also a good idea to block the tire opposite of the flat tire. Therefore, if the left front tire is flat, it would be a good idea to place a brick or other large, heavy object behind the right rear tire. (Your cousin Fred might also be large and heavy, but it's not a good idea to use him to block the tire). Blocking the tire makes the car less likely to move when you are raising it.

Use the tire iron (the L-shaped bar that fits over the wheel lugs) to loosen each wheel lug. The wheel lugs are almost certainly very tight. You'll have to use brute force. Just think about how Mr. T from the "A-Team" would do it and try to be like him. Say to yourself, "Hannibal, I piddy da fool who can't break loose wheel lugs." You'll have those babies loose in no time. You loosen them by turning them counterclockwise, by the way.

Now, at this point, you don't want to actually remove the lugs. You just want them loose. Once you have accomplished this, move the jack underneath the car. If you don't know where the proper jacking points are, look them up in the owner's manual (you keep your owner's manual in your car, right?).

Maneuver the jack underneath the jack point and start to raise the jack. Most car jacks these days are a screw-type scissor jack, which means you simply turn the knob at the end of the jack using the provided metal hand crank. Raise the jack until it contacts the car's frame and continue expanding the jack.


Remove the Flat and Install the Spare


Raise the car with the jack until the flat tire is completely raised off the ground. Once this is done, remove the wheel lugs completely. Depending on how tight the lugs are you might be able to remove them by hand. Set the lugs aside in a secure location where they can't roll away.

Position the spare tire over the wheel studs. This is the most physically challenging part of the whole process. You'll have to hold up the tire and try to line up the holes in the wheel with the protruding wheel studs located on the brake hub. One trick that might help is to balance the tire on your foot while you move it into position.

After you have the spare tire hanging on the wheel studs, screw each of the wheel lugs back on. You'll want to start them by hand. Make sure you do not cross-thread them. The lugs should screw on easily. Once each of them is snug and you can't tighten them any further by hand, use the tire iron to finish the job. At this point, you don't need to get the lugs super tight. You just want them snug for now. Make sure that the wheel is fitting flush against the brake hub.

Once the spare tire is on, carefully lower the jack. Pull the jack away from the vehicle. The final step is to tighten down the lugs completely. The reason you tighten the lugs now is that the tire is on the ground and it won't rotate around like it would if it was still hanging in the air.

Wheel lugs have a specific torque rating that they are supposed to be tightened down to, but there is pretty much no way you can figure that out using a simple tire iron. The general rule here is to tighten down the lugs as much as possible. Again, think Mr. T. "I ain't flying on no plane with loose wheel lugs, Hannibal!"

That's it. Put the flat tire in the space where the spare tire was and put the jack and tire iron back in the car. Most compact spare tires are smaller than regular tires (they look dinky and people commonly refer to them as "rubber doughnuts"), so it is possible that the flat tire won't fit in the spare tire well. Also, compact spares have a limited top speed. The tire's top speed will be written on its sidewall. If your vehicle has a full-size spare, you won't encounter these problems. With the spare installed, you should be able to reach your house or the nearest service station.


Monday, September 1, 2008

Vehicle Safety Check

With the holiday season fast approaching I thought we should take a look at the basic items on a vehicle safety check. I strongly suggest having a qualified mechanic carry out a full service and tune-up before contemplating any long trips and that combined with these few basic tips should see you get to your destination without any mechanical dramas.


  • The first item on the list is a check of the lights - headlight, both high and low beam, the indicators front and rear, parking lights front and rear, number plate lights and with the help of an assistant check your brake lights including the eye-level brake light if fitted.
  • Number Two is your wiper blades. There is nothing worse than getting caught in a rain shower with crappy wiper blades and usually they get overlooked until this happens! Throw a bit of water on the windscreen, operate the wipers and look for a nice streak-free finish. A handy tip that I allways use is get yourself a bottle of Rain-X and periodically wipe your windscreen with a cloth wet with the Rain-X. This stuff is awesome at beading any water that hits the screen and the water is blown off by the wind. Car polish is also useful for this.
  • Washer Fluid and Washer Jets. Another forgotten item until they are needed! Top up the fluid bottle with water and an approved detergent. Operate the washers and if any are blocked a poke with a sewing pin usually gets them working again. Also check the jets alignment, no use using your water to wash the guys windscreen behind you! You can re-align the jet by sticking the sewing pin into the jet and gently moving it in the direction you need it to go.
  • Tyres, please check your tyres before heading off anywhere. Check for adequate tread depth across the entire tread surface of the tyre. If there is major wear on one side of the tyre only I suggest you have a wheel alignment carried out before going anywhere as there may be problems that need to be corrected sooner rather than later.
  • Tyre Pressures. Most service stations have facilities for checking tyre pressures if you don’t have a guage or compressor at home. 32-34psi for passenger car tyres and 40psi for 4×4 and Light Truck tyres is a good operating pressure. If you are carrying a reasonable size load on your trip away increase the rear tyre pressure by around 4psi to cater for this extra load. Having correctly inflated tyres not only prolongs tyre life, it also helps reduce fuel consumption. Don’t forget to check the spare tyre!
  • Fan Belts, mostly referred to these days as drive belts. Check your fan belts for any signs or cracks or deterioration. If in any doubt have a mechanic check and/or replace them. Ask for the old ones to be returned and keep them as spares. You never know when they may come in handy. Tieing up annoying relatives, you know, that sort of thing.
  • Radiator and Heater hoses. Check all the water carrying hoses for splits and deterioration, once again if in doubt have a mechanic take a look.
  • All under-bonnet fluid levels. Engine oil level and condition, Transmission fluid level and condition, Coollant level and condition including the overflow bottle, Battery electrolyte level, Brake Fluid level and condition. As above, if anything looks suspect have a mechanic take a look before you head out.
  • Differential Oil level and condition. This one may be too adventurous for some people so ask your mechanic to make sure that they check it when you have a service done. You would be surprised at how many mechanics don’t check these basic things when servicing cars.
  • Another point to note - we had quite a few cars at our workshop that has stopped due to dirty fuel filters. With an efi engine it doesn’t take much of a fuel pressure drop to cause problems and the fuel filter is often over-looked when servicing a car. If you are unsure of when yours was last changed, change it yourself or have a mechanic do it for you, just to be sure. It is a small price to pay when you consider what a breakdown could cost you.

As I said these are only basic items that anyone can check and there is certainly more to consider in a vehicle safety check so please have your mechanic carry out a service and tune-up before heading off on a long trip. It is money worth spending when you consider the possible costs involved in a breakdown.

Remember to take plenty of breaks along the way and if you are travelling with small children I wish you the best of luck. Have plenty of games to keep them occupied or at least a bottle of Phenergan and a large rubber mallet for those trying times!

DRIVING

If you've been out on the roads, you know that not everyone drives well. Some people speed aggressively. Others wander into another lane because they aren't paying attention. Drivers may follow too closely, make sudden turns without signaling, or weave in and out of traffic.

Aggressive drivers are known road hazards, causing one third of all traffic crashes. But inattentive driving is becoming more of a problem as people "multitask" by talking on the phone, eating, or even watching TV as they drive. We can't control the actions of other drivers. But learning defensive driving skills can help us avoid the dangers caused by other people's bad driving.


video



Skills That Put You in Control

Before you get behind the wheel of all that glass and steel, here are some tips to help you stay in control:

Stay focused. There are a lot of things to think about when driving: road conditions, your speed, observing traffic laws and signals, following directions, being aware of the cars around you, checking your mirrors — the list goes on. Staying focused on driving — and only driving — is key.

Distractions, like talking on the phone or eating, make a driver less able to see potential problems and react to them. It's not just teen drivers who are at fault: People who have been driving for a while can get overconfident in their driving abilities and let their driving skills get sloppy. All drivers need to remind themselves to stay focused.

Stay alert. Being alert (not sleepy or under the influence) allows you to react quickly to potential problems — like when the driver in the car ahead slams on the brakes at the last minute. Obviously, alcohol or drugs (including prescription and over-the-counter drugs) affect a driver's reaction time and judgment. Driving while tired has the same effect and is one of the leading causes of crashes. So rest up before your road trip.

Watch out for the other guy. Part of staying in control is being aware of the drivers around you and what they may suddenly do so you're less likely to be caught off guard. For example, if a car speeds past you on the highway but there's not much space between the car and a slow-moving truck in the same lane, it's a pretty sure bet the driver will try to pull into your lane directly in front of you. Anticipating what another driver may do prepares you to react.

Eight Secrets of Super Driving

When you drive defensively, you're aware and ready for whatever happens. You are cautious, yet ready to take action and not put your fate in the hands of other drivers. According to the U.S. Department of Transportation, 90% of all crashes are attributed to driver error.

Following these defensive driving tips can help reduce your risk on the road:

  1. Think safety first. Avoiding aggressive and inattentive driving tendencies yourself will put you in a stronger position to deal with other people's bad driving. Leave plenty of space between you and the car in front. Always lock your doors and wear your seatbelt to protect you from being thrown from the car in a crash.
  2. Be aware of your surroundingspay attention. Check your mirrors frequently and scan conditions 20 to 30 seconds ahead of you. If a vehicle is showing signs of aggressive driving, slow down or pull over to avoid it. If the driver is driving so dangerously that you're worried, try to get off the roadway by turning right or taking the next exit if it's safe to do so. Also, keep an eye on pedestrians, bicyclists, and pets along the road.
  3. Do not depend on other drivers. Be considerate of others but look out for yourself. Do not assume another driver is going to move out of the way or allow you to merge. Assume that drivers will run through red lights or stop signs and be prepared to react. Plan your movements anticipating the worst-case scenario.
  4. Have an escape route. In all driving situations, the best way to avoid potential dangers is to position your vehicle where you have the best chance of seeing and being seen. Having an alternate path of travel is essential, so take the position of other vehicles into consideration when determining an alternate path of travel.
  5. Follow the 3- to 4-second rule. Since the greatest chance of a collision is in front of you, using the 3- to 4-second rule will help you establish and maintain a safe following distance and provide adequate time for you to brake to a stop if necessary in normal traffic under good weather conditions.
  6. Keep your speed down. Posted speed limits apply to ideal conditions. It's your responsibility to ensure that your speed matches conditions.
  7. Separate risks. When faced with multiple risks, it's necessary to address them by separating risks. Your goal is to avoid having to deal with too many risk factors at the same time.
  8. Cut out distractions. A distraction is any activity that diverts your attention from the task of driving. Driving deserves your full attention — so stay focused on the driving task. video
If you're interested in taking a defensive driving course to help sharpen your driving knowledge and skills, contact your state's Department of Motor Vehicles (DMV). All states keep a list of defensive driving courses that are approved by the state — some even offer courses online. They cost money, but some insurance companies offer insurance premium discounts for the successful completion of a course.


Source: http://kidshealth.org/

Thursday, August 7, 2008

Shifting Techniques

Manual Transmission

by: Brian Brown

"Heal and toe" refers to the right foot position as it operates both the gas and the brake pedal at the same time. Actually, on most modern cars it's better to use the ball of the foot (under the big toe) on the brake pedal and the edge of the foot (about halfway between the little toe and the heel) on the gas pedal. I think it's better to refer to it as "ball and edge".

There are some individual variations in position based on foot size, type of shoe, seating position, pedal placement, and so on.

It's important to give preference to the brake pedal for safety reasons, and because the brakes require more accurate control feel than the engine speed.

I have size 11 shoes. In my ti I position my foot so that my heel is on the floor near the base of the gas pedal. The ball of my foot is centered half way top to bottom on the brake pedal, with the edge of the brake pedal at my middle toe. My foot is in approximately the eleven o'clock position when I am doing this. In this position I can firmly apply the brakes, and the control feel is pretty much the same as if I was operating the brake pedal alone. By rocking my foot, I can apply the gas without varying the pressure on the brake pedal (this is one part in particular that takes practice). When I'm done braking, I slide my foot over so that it's directly on the gas pedal. My heel has remained on the same place on the floor.

Some people, particularly with smaller feet, don't keep their heel on the floor. There are some other cars that I lift my own heel from the floor. I like to have it on the floor if possible because it makes it easier to consistently control the brake pressure while rocking the foot. It's important not to have the seat too far back because the knee needs to move side to side just a little bit when doing this. Having the leg stretched out too far restricts this motion.

Aftermarket pedal covers can benefit some cars and foot sizes by bringing the edges of the pedals closer together and by changing the height relationship between the pedals. On some cars with hanging gas pedals, the gas pedal can be bent to a more favorable position (this can't be done on the ti because the pedal is hinged from the floor). I don't recommend trying to bend the brake pedal. Also be aware that pedal covers can reduce the space for a larger foot to fit between the brake pedal and the center console.

I have found the stock pedal positions to be quite good for me. Obviously this is a highly individual thing. I would suggest that people spend a significant amount of time experimenting with foot positioning before trying to reposition the pedals or investing in pedal covers.

Why heel and toe (ball and edge)?

One basic situation is starting up hill. Ball and edge allows a smooth transition from brake to gas while operating the clutch with the left foot so that the car doesn't move backwards.

Many people also use the term "heel and toe" to refer to rev-matching while shifting and/or double clutching, but it's actually just one component of these processes.

Rev-matching refers to matching the engine speed to the transmission input speed before re-engaging the clutch. This is particularly desirable when downshifting for a corner. In a hard corner, the suspension needs to be stable and the tires need to be loaded so that all of their traction is being used to generate cornering force. If the engine is at a different speed than the transmission input when the clutch is re-engaged, this will generate a force on the driveline that will upset the stability of the suspension and will cause the tires to exceed their traction capability if the corner is being taken near the limit.

It *is* necessary to rev-match if a corner is to be taken near the limit. It isn't necessary for slower corners, but it will make them smoother.

Double clutching is a technique for rev-matching the transmission's *intermediate shaft* to the output gear that is to be selected. This is a function that is normally handled automatically by the transmission's synchro-mesh gears (or synchro's). It is useful to double clutch for extreme gear changes, for older transmissions with worn synchro's, or simply to save wear on the synchro's. It's also an entertaining thing to do.

Before I get into the specifics of rev-matching and double clutching, it would probably be good to review the inner workings of the clutch and transmission.

The ti's gasoline engine has a limited output bandwidth of approximately 1000 to 6000 RPM. It can't operate from 0 RPM (like an electric motor can), so it needs a device (the clutch) to disconnect it from the drive train so that it can idle while the car is at a standstill. The power is not constant from 1000 to 6000 RPM, so it is also necessary to have different gear ratios in the transmission to extend the car's useful operation speed range and to maximize available acceleration. The clutch also serves to disconnect power to the transmission when changing gears.

THE CLUTCH:

The clutch is integrated with the engine's flywheel. There is a disk with friction material, similar to a brake pad, that is connected to the transmission input shaft on a sliding spline. This disk is surrounded by the flywheel surface on one side, and the pressure plate surface on the other side. The pressure plate is spring loaded to squeeze the clutch disk against the flywheel, effectively making a solid connection. The pressure plate can be moved by pressing down on the clutch pedal. This releases the coupling pressure between the flywheel and the clutch disk so that they can rotate independently.

There are three states the clutch can be in:

CLUTCH DISENGAGED (pedal pressed down): The engine flywheel and the clutch disk can rotate independently. No power is being transferred.

CLUTCH SLIPPING (pedal brought up just to the point that the clutch starts to grab): The engine flywheel and the clutch disk are still rotating at different speeds, but power is being transferred. If the clutch pedal is continued to be brought up properly, the speed of the engine and the clutch disk will be brought together. This is the state that clutch wear occurs.

CLUTCH ENGAGED (pedal up): The engine flywheel and the clutch disk are locked together. Full power is being transferred, and no clutch wear is occurring.

THE TRANSMISSION:

The transmission has an input and an output. The ti has five forward gear ratios (fifth gear is a straight 1:1, not an overdrive) and one reverse gear ratio. The forward gears are all *constant-mesh*, that means that the gear teeth for all ratios are always engaged with each other at all times. Instead of sliding a gear out of engagement with another gear, the gear is disengaged by disconnecting it from the *shaft* that it is on. Only one gear ratio pair can be connected to the shaft at one time. The reverse gear is an actual sliding gear whose teeth actually slide out of engagement when it's not being used.

Each forward gear can be coupled to its shaft by a sliding locking coupler. This coupler connects splines on the shaft to splines on the gear. The coupler needs to be at the same speed as the gear splines to avoid grinding. (When people refer to "grinding the gears", it is actually the splines that are grinding, not the gear teeth). To synchronize the coupler with the gear splines, there is an intermediate device called a synchro-mesh.

The synchro-mesh is a lightweight ring with spline teeth on one side, and a conical friction surface on the other side. It is positioned between the sliding coupler and the gear splines. The gear also has a conical friction surface that mates with the surface of the synchro-mesh.

When a gear is to be engaged, the shift linkage selects a sliding coupler to connect to a gear. At this point, the coupler and the gear to be engaged are usually spinning at different speeds. As the coupler starts to slide, it first engages the spline teeth of the synchro-mesh ring. Because the synchro-mesh is so lightweight, it can virtually instantly change speed to match the sliding coupler that was just forced into engagement with it. It then becomes part of the coupler. As the coupler continues to slide towards the gear splines, the friction surface of the synchro-mesh ring is pressed into contact with the friction surface of the gear assembly. This friction causes the transmission's input shaft (which at this point is hopefully disconnected from the engine by the clutch) to be accelerated (or decelerated) so that the coupler and the gear are spinning at the same speed when their spline teeth finally engage.

I think it's helpful to find some junk transmission parts to move around by hand to help visualize this process.

A synchro-mesh is limited in how much mass it can accelerate and how fast it can do it.

DOUBLE CLUTCHING:

There are *three* separate spinning entities that need to be coordinated when shifting: The engine. The transmission input. (I'm going to refer to this as the intermediate shaft). The transmission output (which is directly related to the vehicle speed).

When the clutch is disengaged (pedal pushed down) and the transmission is in neutral (such as when shifting between two gears), the intermediate shaft is essentially free spinning. In normal shifting, we rely on the synchro's to control the speed of the intermediate shaft as it engages with the gears connecting it to the transmission output.

Decades ago, transmissions didn't have synchro-mesh. (Many large trucks still don't). On these transmissions, it is necessary for the driver to manually control the speed of the intermediate shaft so that it matches the speed of the gear to be engaged. This is done by the following process when shifting from one gear to the next:

1) Power is removed and clutch is disengaged (pedal down). 2) Transmission is shifted from original gear to neutral. 3) Clutch is re-engaged (pedal up). (Driver now has control of intermediate shaft speed by controlling engine speed). 4) Driver 'blips' throttle to match intermediate shaft speed to speed of new gear. (This takes practice to get the right match). 5) Clutch is disengaged (pedal down). 6) Transmission is shifted from neutral into new gear. 7) Clutch is re-engaged (pedal up) and power is applied.

Steps 1 - 3 can be done casually or quickly. Steps 4 - 6 *must* be done quickly so that the intermediate shaft doesn't slow down again before it's engaged. If step seven is also done quickly, the engine will also be 'rev-matched' to the rest of the driveline so that engagement will be smoother.

REV-MATCHING:

When taking off from a stop and then going up through the gears, steps 1,2,6,7 above are the normal shifting method for each gear change. The synchro-mesh are more than enough to control the intermediate shaft speed. The engine will passively rev-match itself because it slows down naturally and this is appropriate when shifting up.

When down shifting, the engine needs to spin faster as it engages the new gear. This can be achieved by 'blipping' the throttle as the transmission passes through neutral. If the engine isn't manually sped up by the driver, it will be sped up by the driveline when the clutch is re-engaged. This can be OK for normal street driving, but if the car is cornering near the limit this can upset the suspension and the tire adhesion.

The synchromesh are usually adequate intermediate shaft control when down shifting one or two gears. Aggressive downshifts (like a 5 - 2 shift from high speed) can benefit by using double-clutch shifting to assist the synchro's. Shifting into first gear in a hard corner is nearly impossible without double-clutching (this is useful for those really tight hairpins, especially if they exit uphill).

LEARNING TO DOUBLE CLUTCH, REV-MATCH, ETC...

I think that the biggest problem people have learning these techniques is that they try to incorporate everything all at once. The following are suggestions that I have for progressively learning things one at a time.

GETTING INTO GEAR AT A STOP:

Because the synchro-mesh doesn't operate unless something is turning, it's easiest to get into first gear by shifting from neutral into first just before the car comes to a complete stop. If the car is already stopped, a lot of extra force may sometimes be required if the spline teeth don't match up. (Sometimes it might help to briefly re-engage the clutch to spin things around again). If the car is moving too fast, a lot of effort is required to get the lever into first (it might even 'crunch' if the synchro's capabilities are exceeded).

Try this exercise: When slowing to a stop, push in the clutch and *lightly* press the shift lever from neutral towards the first gear slot at around 10 MPH. Don't force it in. As the car slows down, there will be a point that the lever easily slips into gear by itself. This will occur just before the car comes to a stop.

What is happening here? The intermediate shaft quickly slows down (due to friction) to near zero speed. This results in a fairly large speed difference between the intermediate shaft and first gear. The first gear synchro *resists* the lever movement. As the car slows down first gear also slows down. When the car is almost to a stop, first gear has slowed down to the point that it nearly matches the intermediate shaft's speed. At this point, the synchro is able to accelerate the intermediate shaft to a matching speed. When the speeds match, the force required to engage the splines is reduced, and the lever slips into place.

This is a rather slow, passive rev-matching situation. Using this technique results in a smooth, low-effort engagement into first gear when coming to a stop at a light. It reduces the wear on the first gear synchro.

More importantly, this is a good way to learn to recognize the 'feel' of a properly actuated synchro. This light - touch engagement is something to strive for when learning to actively match revs with the engine and double clutching. Some people refer to this as treating the shift knob like an eggshell. By *accurately* shifting, shifts can actually be done faster than by forcing the shift lever with muscle. Again, it also has the benefit of reducing transmission and clutch wear.

SIDE NOTE ON GETTING INTO REVERSE:

Because reverse is done with an actual moving gear (and no synchro's), the car and the intermediate shaft must both be stopped for the gear teeth to match up. This is most commonly a problem if a person wants to go into reverse after the car has been idling in neutral. If one just pushes down the clutch pedal and shifts into reverse, it will grind.

One approach is to simply wait a couple of seconds after pushing down the clutch pedal so that the intermediate shaft can come to a halt before shifting into reverse. To do it faster, you can push down the clutch, shift briefly into one of the forward gears (using its synchro to slow down the intermediate shaft) and then shift instantly into reverse.

To instantly get into reverse after braking in a hard stop (such as when driving a gymkhana course), leave the transmission in the forward gear you were in. At the moment you get to zero speed, the lever can be thrown into reverse (because the intermediate shaft was halted when it was engaged to the last gear), and power can then be immediately applied.

SHIFTING UP WHILE ACCELERATING:

When shifting up from one gear to a higher gear both the engine and the intermediate shaft will naturally slow down. This will passively bring them near the speed of the higher gear. Because of this, active rev-matching or double-clutching are rarely required.

Another exercise: When upshifting, try to use the same 'egg-shell' pressure on the shift lever to slip it into the next gear. When the clutch pedal is pushed and the shift lever moves through neutral, the intermediate shaft drops in speed and will quickly match the speed of the higher gear. This is the point that it will almost *seem* to pull itself into gear. The engine takes slightly longer to slow down because it has more inertia. This usually works out well because it is a moment after the gear is engaged that the clutch needs to be re-engaged. If the clutch is re-engaged and the power smoothly reapplied at just the right time, there won't be any 'shock' in the drivetrain.

It's a little hard to describe in words, but with practice it's possible to integrate this entire upshift sequence into what seems like a single fluid motion that takes only a fraction of a second.

There are three indicators to determine how good a shift is: Was only light pressure required on the lever? Was the shift smooth? Was the shift fast?

To be complete, I should mention that there is one exception for forcing the shift lever. To get the very last little bit of acceleration out of a car, it can help to rush the shift sequence by forcing the shift lever into the next gear and re-engage the clutch with the engine already on-power. This can *slightly* reduce shift time and throw some extra inertia from the engine into the drive train. This technique definitely adds wear to the synchro's, the clutch and the rest of the drive train. If the car isn't being pushed to the point of lighting up the tires (which also accelerates wear), this technique isn't worthwhile.

Generally speaking, a really well executed light-touch shift can be done quicker than most people can power-shift. It certainly is friendlier to the car. The car will also handle better if it's accelerating on a twisty road. I usually only power-shift if I'm drag racing.

DOWNSHIFTING:

There are three basic scenarios involving downshifting that I can think of:

Downshifting (without braking) from an established original speed (such as when passing another car).

Downshifting while braking, and then re-accelerating in a straight line (no corner, such as when braking for a car that is turning up ahead).

Downshifting while braking to enter a corner.

(OK, I suppose there might also be occasion to downshift to enter a corner without braking, like when turning off a road with a low speed limit).

I listed these three scenarios in what I considered to be their order of difficulty.

Most people when they're learning to drive a manual transmission, learn to deal with downshifting for a corner first. They do it without active rev-matching or double-clutching (which, of course, is fine). By approaching and going through the corner at a casual rate, there isn't a big speed difference in the engine, intermediate shaft, or the rest of the driveline. The synchro's can handle the engagement, and it's possible to smoothly engage the clutch while *exiting* the corner. With additional practice it's possible to use this type of technique to get through corners reasonably quickly.

What's necessary to get through a corner as quickly as possible?

The tires basically have a fixed amount of traction on any given road surface. This traction can be used for braking, cornering, accelerating, or a combination of braking-cornering or accelerating-cornering. If the car is cornering near the limit, there is no traction available for braking or accelerating.

The suspension needs to stay stable and the steering needs to be a smooth as possible.

In simple terms, a good corner consists of braking in a straight line, smoothly transitioning into the corner, holding the corner for its tightest section, transitioning out of the corner onto the gas, and accelerating out of the corner's exit.

The two transitions are the most important parts here. The idea is to have the tires near their maximum traction while braking, and then to smoothly change the *direction* of the traction to sideways for the corner. It's the same thing when exiting the corner. The direction of the traction is changed so that car accelerates.

I want to re-emphasize that the goal is to hold the *level* of the tires' traction CONSTANT, while CHANGING only the *direction* of that traction.

If there is a gap between releasing the brakes and steering into a corner, two things occur. The suspension becomes unsettled (so it can't corner as well), and time that the tires could have been working is lost. Again, it's the same thing when getting out of the corner to accelerate.

How does shifting affect all of this? If there is any jerking of the driveline when cornering near the limit, this will cause the limit to be exceeded because of the additional load imposed, even though momentary, on the tires. The driver has to be concerned with interpreting the corner and the situation, and monitoring how the car is responding, all while trying to operate a steering wheel, shift lever and three pedals with two hands and two feet.

Most 'performance' corners require a reduction in speed. This implies that a downshift of one or more gears be made so that the car is in the correct gear to accelerate out of it. A five - two downshift is a big change.

When driving a fast corner, the downshift can't be done before braking because the car's initial speed would cause the engine to over-rev.

On a rear wheel drive car, power needs to be lightly applied to the wheels during the corner so that the suspension is neutral or oversteering slightly (this is touching on another subject). This means that the downshift needs to be done before entering the corner.

This leaves one place to downshift: towards the end of the braking phase of the corner.

The shift has to be done while braking, and the engine needs to be sped up so that it will rev-match the new gear so that the tires won't be jerked past their limit. All three pedals need to be operated at once. This is where heel and toe (ball and edge) operation of the brake and the gas is required. Depending on how many gears down the shift is, the abilities of the transmission's synchro's, and the general pre-disposition of the driver, double-clutching may also be called for to get the shift lever into gear.

BACK TO LEARNING THE TECHNIQUES:

Recall the three downshifting scenarios I described above. Many people that I've observed trying to learn to rev-match and double-clutch (including myself) will try to learn it while cornering. This is the most difficult downshift. It's much easier to practice without braking or cornering. The braking can be added second, and then finally the cornering.

Please remember to stay safe. Try to keep away from traffic when trying something new.

EXERCISE:

On a straight section of road, establish a steady speed in fifth gear (perhaps 50MPH). Without breaking (use your right foot on the gas pedal only), downshift into forth. Try to blip the gas as the shift lever passes through neutral so that the car doesn't doesn't pull backwards or forwards when the clutch is re-engaged. Don't try to accelerate once you're in forth. Just continue to maintain a steady speed. Shift back up into fifth. Again, try not to jerk the car. Repeat this sequence going back and forth from fifth to forth. If you've got everything right and smooth, the car will just go steady down the road as if you weren't shifting. The only thing different is the sound of the engine changing speeds. At least at first, don't worry about making the shift fast.

Next, try the same thing going back and forth between fifth and third. This will require a little more gas when blipping the throttle. Focus on keeping the car's forward motion rock-steady.

Once you've got that down, try different sequences of third, forth and fifth.

At this point, you might want to throw in double-clutching while downshifting. As the shift lever passes through neutral, momentarily let up the clutch pedal at the same time the throttle is being blipped. If it's done correctly, the shift lever should slip into place much easier than without double-clutching, especially when going from fifth to third.

Try a similar exercise at 40MPH using second, third and forth. When you can downshift into second (this usually requires double clutching) at 40MPH and not affect the car's motion, you've got a good handle on this exercise.

The last part of this exercise is to accelerate at the end of a downshift. The idea is to be going at a steady speed, downshift by two gears, and take off. Try to integrate this into a single fluid motion. The acceleration should just appear as a big push from behind, without any jerking. Slow back down to a steady speed and repeat.

It is a rare automatic transmission that can downshift from speed as good as a well done downshift with a manual.

If you are new to this, I wouldn't proceed past this exercise for at least several days of practice, and probably weeks.

EXERCISE WITH BRAKING:

With the car off, try to find a seating and foot position that allows you to operate the brake and the gas pedal with your right foot at the same time using the ball and edge position I described. While pushing on the brake pedal, try to learn to blip the gas pedal without varying the pressure on the brake.

This inevitably will feel *very unnatural* at first.

In the course of your normal driving, practice blipping the gas pedal while you brake (don't try to downshift). Trying doing it during light braking and heavy braking. Try to bring the engine up to different speeds. The idea is just to get used to blipping the throttle while braking, without worrying about accomplishing anything with the engine. The goal is to not let the operation of the gas pedal affect the braking.

When you think you're ready, try braking and blipping the gas to rev-match into a downshift.

The next step requires an open stretch of straight road without traffic.

Basically just brake from speed, to a rev-match downshift at the *end* of the braking. Accelerate back up and repeat. Try it with and without double-clutching. Try it with light braking and heavy braking.

All the usual goals apply: Smooth transitions. Light touch on the shift lever. Unified fluid shift motions.

Stop and go traffic is an excellent opportunity to practice this exercise. I know people that dislike driving a manual transmission during rush-hour. Personally, I prefer a manual because it gives me something interesting to do with my driving in an otherwise tedious situation.

CORNER ENTRY EXERCISE:

Suspension loading might best be practiced first without downshifting. The exercise is only about getting into a corner. Just push in the clutch while braking and don't worry about the gas. Wait until the corner is completed before trying to downshift or speeding up again.

Brake as you approach a corner. Try to be conscious of the level of braking force that you feel. When you reach the point where you start to turn the steering wheel, lift off of the brake in unison with moving the steering wheel.

The goal is to feel the force swing sideways without varying in intensity. You shouldn't feel any gaps in the 'tug'. There also shouldn't be any pulses in the force. Keep it smooth and uniform.

Try varying how fast you turn in. The faster you turn in, the faster you need to get off the brakes. Doing corners with slow turn-in is good for practice because it emphasizes the steering/braking coordination more.

FINALLY, THE WHOLE DEAL:

If you've gotten through all of the exercises up to this point, adding the final steps should be a relatively easy process.

Brake timing doesn't have to be an issue at first if you practice at reduced speeds with moderate deceleration. The main thing to focus on is to get the downshift timed so that it is *completed* just before you start to turn the steering wheel. As the clutch is re-engaged, the gas should be held at the level where it will be during maximum cornering force.

Transition the braking into steering as in the previous exercise. When it's time to straighten out, transition into the gas in a similar manner. Just swing the direction of the force around without any gaps or surges.

Here's the entire step by step process for a 90degree corner from a 55MPH road to another 55MPH road:

1) Begin braking. 2) Clutch pedal down, transmission lever in neutral. 3) Clutch up, blip throttle. 4) Clutch down, lever into second. 5) Clutch up, lightly apply the gas just enough to load the drivetrain. 6) Transition off of the brakes into the steering. 7) Hold the corner (maintain the gas just below where the back end would start to slip out. 8) Transition out of the steering into full gas. 9) Shift up when needed.

FINAL NOTE:

The whole process of learning to shift well takes lots of practice and determination, but it's well worth the effort. Everyone that I know who's learned to do this really ENJOYS shifting. I believe all of them have a really strong preference for manual transmissions. I know that I do.

I hope that all of this makes sense and that some of you will benefit from both the explanations and the exercises.

Regards,

Brian Brown. BMWCCA #130878 '96 318tiS

The difference between an automatic transmission

The difference between an automatic transmission and a manual transmission can be summed up pretty much by the names. The automatic transmission will shift gears automatically according to the speed of the drive shaft and the engine rpm, A manual transmission will shift gears according to the input of the driver. Both are good for many reasons and both have their own quirks and idiosyncrasies.

For the beginner driver it is easier to learn the fundamentals of the road with an automatic because you're not fighting your car as well as dodging other cars. With an automatic the driver basically steers and controls the acceleration and deceleration of the car. The transmission does all the work of selecting the proper gear for the speed you are traveling. It removes the driver along with diver error from the shifting. Of course you can select what gear you want to be in with an automatic for certain applications, and as always a reverse gear. You can put the automatic transmission in 1st gear if you are pulling a load up a steep hill and you don't want the transmission shifting into a higher gear making it harder on the motor. On the whole however the driver will put the car in "Drive" and then forget about the gears until they are finished and put it in "Park".

The manual transmission requires the driver to make all the shifting decisions and also has to use the clutch. This takes a fair amount of concentration and requires all your limbs to be in good working order to drive properly. The driver must engage the engine with the transmission slowly and smoothly with the clutch in order to start moving and must then shift gears according to the speed he is going. Each time disengaging the motor from the transmission using the clutch, sliding the shift lever into the proper position and then reengaging the motor. This transmission gives the driver much more control over the vehicle, but also makes the driver responsible for all the shifting. Bad things can happen if the driver selects the wrong gear. You can stall a vehicle or possibly go into a compression skid situation. Once mastered however the act of shifting will become so common place that it will become second nature.

Each transmission is good for different reasons. If you are driving in the city and doing lots of stopping a starting the automatic will be much easier to drive. If you are off road and need a feather touch on the clutch to get over that certain obstacle then the manual is better. Most race cars are manual except for some drag cars where the driver has chosen the transmissions to shift so he can't make a mistake. On the whole cars and trucks today are coming out with automatics, which make the car drivable to a wider range of people. However if you take the time to learn how to drive a standard I think you will be pleased.


Automatic Transmission Pedal


Shifter for Automatic Transmission


Shifter for Manual Transmission


Manual Transmission Pedal

Tuesday, July 15, 2008

VolksWagen Moods


VolksWagen Transporter: Nice Moods!

VW Transporter
We found a very nice article about the VW Bus including many pictures of great mods. Enjoy!

VW Transporter
VW Transporter

Thursday, June 19, 2008

Driving Tips

Our top 20 tips for smooth sailing on the road

Hitting the road on your next trip? Whether you're heading to Grandma's with the kids or hitting Route 66 for a cross-country jaunt, don't leave home without our tried and tested driving tips. Read on to learn more about avoiding traffic, saving money, and staying safe (and staying awake!) on your next road trip.

1. Before beginning a long drive, always get enough sleep and eat something before you go. Highly caffeinated beverages are not necessarily the best way to stay awake while driving. While initially you will feel more alert, the effects can recede with time, and your attention may wander although you remain awake.

2. Pull over and take breaks every couple of hours, even if you don't feel sleepy. Grab a snack, get some fresh air, and stretch your legs by walking around. If you need to, take a quick nap.

3. If you can, share the driving responsibilities with someone else. This will allow you to keep an eye on each other while driving and also enable you to nap without losing time. If you're driving alone, turn on the radio or put on some music, and keep your window cracked open. You may also want to refrain from using your cruise control if you're driving alone at night -- having to concentrate on maintaining your speed can help you stay awake.

4. If you do have to pull over -- pull off the road. Never park on the shoulder or in the breakdown lane for any reason except an emergency.

5. Know the laws along your route concerning cell phone use while driving. While it may be legal in one place, it may be illegal in another, and ignorance is not typically an acceptable excuse for a violation. Here's a handy chart of cell phone laws by state (keep in mind that this information can change at any time). However, even if it's legal to talk on a cell phone where you're going, it's usually safest to use a hands-free device.

6. If you don't know this one, shame on you. Never drink any alcohol before your trip. While you may not become intoxicated from one beer, you will become sleepy.

7. Keep an eye on the skies, and if you can, plan a route around inclement weather. A minor detour could actually wind up saving you major time.

8. Search the Web for traffic update sites and listen to radio traffic alerts, especially when approaching major cities. All-news stations on the AM dial are often your best bet. For more on cell phone directions, traffic reports and other useful travel information, check out Road Trip Resources.

9. You should plan out your exact route before you even leave the house -- but bring along a map just in case. While many folks like to print directions from Mapquest, Traveler's Ed examines a few other options in Mapping on the Web.


10. If you are driving a rental vehicle, familiarize yourself with the car and all of its equipment (horn, brakes, hazard lights). For an amusing but true look at this issue, see The First 10 Minutes of Your Car Rental.

11. Lock all of your valuables (especially items that are clearly gifts) in the trunk or glove compartment and stow all luggage in the trunk.

12. Familiarize yourself with local traffic laws, which vary from state to state and especially overseas. Is it legal to make a right turn at a red light? What are the rules on yielding to pedestrians? For more on international car travel, see Renting a Car Abroad.

13. Before setting off on a long car trip, be sure your vehicle is in prime condition -- that tires are properly inflated, that all fluids are at their proper levels and that you have a full tank of gas. (For particularly long road trips, you may want to have your mechanic do a more thorough check.)

14. Consider becoming a member of AAA or signing up for your car insurer's roadside assistance program. You won't regret it when your car breaks down on a lonely back road.

15. Keep costs down by conserving gas as you drive. Minimize sudden starts and stops, empty your car of all unnecessary weight, and slow down -- it takes much less fuel to drive 55 miles an hour than it does to drive 70. For more ideas, see Save Gas and Money.

16. Don't wait until your gas gauge is sitting on E to refuel. On an unfamiliar road, you never know when the next gas station will appear. As soon as you hit a quarter of a tank, start looking for a place to fill up.

17. When traveling with kids, be sure to stop often -- not just for snacks and potty breaks, but also for fun. See a cool playground along the way? Pull over and throw a Frisbee around. You'll also want to pack toys, books and music for the car -- not to mention your motion sickness remedy of choice. For more ideas, see Family Car Travel.

18. Feeling munchy? Stock up on snacks and drinks at grocery stores rather than gas stations or convenience stores -- you'll get a wider and healthier selection, as well as better prices.

19. On longer trips, keep napkins, plasticware and a small cooler handy for meals on the go. You'll also want some spare change for tolls, as well as a first-aid kit, flashlight, pillow and blanket. Keep a set of jumper cables, a spare tire or donut, and extra fluids for the car (such as windshield wiper fluid) in your trunk.

20. This last tip should go without saying, but it's important enough that we'll say it anyway: Make sure everyone in the car buckles his or her seatbelt. Not only will it keep you safe, but in many places it's also the law.



Source: http://www.independenttraveler.com/