Precision. Quickness. Perfection. Smoothness. Feel. And decent reliability, enough that it does not break under harsh usage in the middle of a race (this has happened more times than you think). This is what you would want from your gearbox if you want to win races. If you have a good engine, good chassis, good tires, good suspension, all-in-all the best car in the whole grid, if you have a bad gearbox, you are done for, and you can forget winning. Gearbox is a vital component of any car, be it a racecar, or a typical road car. It is the gearbox which controls and distributes the power of the engine to the axle, to the differential, and to the tires, which makes the car go ahead. It is imperative that a gear box must transfer the maximum, or in some cases, the exact appropriate and precise amount of power from the engine down to the rest of the car to extract the maximum performance from the car and win races. We know a lot about passenger-car gearboxes used by mere mortals. So let us talk about what kind of gearboxes race-cars use.
1. Dog-box manual-If you ask any car enthusiast, or professional race-car driver, which gearbox is the most fun, the most testing, and the most involving of them all, and can give really good results, the answer to all your questions will be the same. The good-old traditional, manual gearbox. If I am allowed to be frank, we common-folk aren’t as skilled in driving fast, as we think. Even if you have a fast car with a swanky, and advanced automatic gearbox, a professional race-car driver will overtake you with ease with a slower car with a manual transmission. Why is that? Because a manual gearbox gives you complete control. Complete control, over the power and how it is to be delivered. However, here is a twist. The manual gearbox in most race-cars is different as compared to the ones in regular cars. Because it is a dog-box. What does “dog-box’’ mean? See, for reference, modern commuter, standard cars that we get today, get a synchro-mesh manual transmission. Why is it called so? Because it has synchronizers, that help you in slotting the car in the right gear, making it smooth and easy-to-use. Race cars however, don’t have synchronizers. They have bigger, and beefier, dog ears. It might be rougher through the gears as compared to a normal manual that we are used to, because there are no synchronizers to guide you through the slots. The advantage? Quick, fast, and at the red-line gear-shifts. You can bang through the gears roughly, even without properly using the clutch, and even while revving the engine to the red-line. Wear and tear will be faster, but it is a race-car, who cares about lasting more than a race? You can jam the car from gear to gear relentlessly. It is all about the violence, and banging through the gears, and red-lining it. Sounds like an enthusiast’s wet dream, eh? Who needs to ease on the clutch? The quicker the better! Dog-boxes make for a visceral experience, and a good example is Colin-McRae’s Subaru 555 Rally Car, which got him the championship. You will see the smile on the faces of the fortunate who got to drive it, that says it all.
2. Dual-clutch automatic transmission-Okay, this is used in most sporty road cars, and street legal supercars. But, this gearbox has every bit the right to be called a sporty gearbox. It has two clutches, one which handles the even gears (2,4,6..) and the other which handles the odd gears(1,3,5..). This makes for quick and precise shifts, both upshifts and downshifts, by using the paddles.
3. Sequential gearbox-Used in Formula-1 and in most types of professional racing, sequential gearboxes, are very important and effective. It follows a sequence, and allows the driver to choose only between the next and the previous gear, allowing no gear skipping in between like a traditional manual. It either utilizes paddle shifters on the steering, or a manual gear-shifter, which allows only previous of next gear. You push the lever only in one direction, ahead or behind, to go up or down the gears. This type of gearbox is known for giving really fast shift times, and that has made it relevant.
4. Automatic gearbox with trans-brake-Automatic or sequential gearboxes, specially modified, are used for drag racing to get the best results. However, in the most competitive drag-race cars, there is something known as a trans-brake. The trans-brake helps a drag car get the best launch, by placing the transmission in forward and reverse gear simultaneously. This prevents the car from spinning out and crashing because of the high amount of torque created by a drag car, keeps the car in place, and gives you the fastest and most efficient launch off the line. It subjects the rear tires and suspension to “increased torque”, allowing you to launch at redline (maximum engine RPM) without slip. How does it work? It is centered around a solenoid or electrical valve, that fools the transmission into thinking that it is in first and reverse at the same time. During launch, you release the trans-brake button and the transmission solenoid releases. So, you can launch like a pro and win races, what’s the catch? Since you are engaging the gearbox in first and reverse at the same time, you can destroy the gearbox, which is already going through lot of load because of the violent torque that your drag car is making. So, be careful.
5. Centrifugal clutch-Want to see the most insane drag race on the planet? Run-of-the-mill American muscle cars and boosted Civics bore you? Then look at top-fuel dragsters. Absolute monsters that put 10000+ horsepower (approximately 100 times the power of your average car), on the tarmac. And how can they put that much power down on tarmac without something blowing up? A centrifugal clutch with-forward, high, and reverse. A centrifugal clutch operates using centrifugal force as the name implies. It is a system of timers, levers, and clutch discs making up a clutch pack. Centrifugal force wants to throw the clutch fingers outwards. That makes them pivot and push the pressure plate into the clutch pack, increasing clamp force. The cannon controls the throw out bearing, limiting the clamping force via a system of timers. Think of them as a very fancy lever. I urge you to see them, if you are into thrill-seeking. They are mad, and they will leave you blinking in shock and awe. They are quite mad machines and a delight to watch, even for seasoned Formula-1 fans.
So, here goes. However, let us end with an interesting addition. Most of us wonder why do some sports cars have that amazing whine as they grow through the gears and redline? Is it because they are supercharged? Wrong answer. It is because they use straight-cut gears, and not helical-gears, like in normal passenger vehicles. This allows them to ruthlessly, quickly, and efficiently bang through the gears. Does your passenger car make a beautiful whining sound while reversing like a race-car? Don’t be surprised, because the reverse gear in a normal car is straight-cut, because it is safe and efficient. Most people ask me-why do I reverse so fast? Now you know why:)
