Monday, December 8, 2008

స్విఫ్ట్-shift


'Boost is the secret of my energy!' declared Kapil Dev, twenty years ago, flashing his trademark toothy smile. The Swift you see here also gets its energy from boost. So much of it in fact that it simply shreds to bits, everIt is mid-afternoon, and Amit and I are on the Mumbai-Pune Expressway, driving along in the fast lane. We've been following a Camry for some time, and I've been gently trying to persuade the Toyota driver to move over. A polite honk and one or two flashes of the headlamp have not worked. He is doing a steady 180km/h or so, and maybe because he doesn't really believe the car behind him can actually overtake his Camry, he's hogging the fast lane. Right, time to get to work then. I take my foot off the throttle momentarily - there's a loud 'wwhooosshhhh!!' from the turbo's wastegate - and downshift to fourth. We move left to the centre lane, and with the throttle floored, our car leaps ahead in one ferocious lunge. There's a look of utter and complete disbelief on the Camry driver's face as our car snarls past. Within seconds, the Toyota is already receding fast in our rear view mirror. We're driving a Maruti Suzuki Swift, and we've just overtaken a 2.4-litre, 142PS Camry that's being driven flat out.
This is no ordinary Swift, of course. It still has a 1.3-litre engine, but instead of the stocker's 88PS, this one packs about 135PS, courtesy a Garrett GT20 turbocharger, which runs 7psi of boost. While we can't tell you who the car belongs to, what we can tell you is that the turbo fitment and all other engine work has been carried out by the legendary (seven times National Rally Championship winner) N Leelakrishnan, who hails from Coimbatore. Leela's technical prowess is widely respected and when he fettles a car, he makes it a point to do it very, very well. And it shows. The Swift here is the ultimate Q-car. You won't find any outsized bodywork here - no bulging wheel arches, no spoilers and no skirts. A huge exhaust poking out discreetly from under the rear bumper, and 15-inch alloys (made by Kyowa Racing) wearing very low-profile 205/50-R15 Michelin Pilot Preceda rubber give the slightest of hint at the performance potential lurking underneath.
Turn the key and the Swift starts with a nice, purposeful burble. Blip the throttle and it snarls loudly, ready to pounce. Put your foot in and then the gloves really come off. All the nice-guy pretensions disappear completely, and the engine howls furiously, demanding to be let off the leash. And the numbers back up the noise. The Swift Turbo launches very hard, albeit with a huge amount rubber-smoking wheelspin, which actually hurts its acceleration times. Still, it goes from zero to 60km/h in 4.42 seconds, to 100km/h in 9.55 seconds, and by the time the needle runs out of numbers on the Swift's 200km/h speedometer, it's doing a measured 192km/h. It just annihilates everything else on the road, flying past long lines of cars and buses in furious bursts of speed and acceleration. It's Conan the Destroyer come alive. It's God's (and N Leelakrishnan's) gift to mankind.
When you consider that a stock Swift does zero to 60km/h in 5.09 seconds, zero to 100 in 11.59 seconds and a top speed of 157km/h, you realise just how much quicker and faster the Swift Turbo is. And we strongly believe that had we been testing on a slightly grippier surface, which offered better traction and less wheelspin, the Swift would have launched harder still and posted much better times. However, what the numbers don't really tell you is just how much of a blast it is, driving this car. It's one of those ultra-rare cars which I would be happy driving day and night, non-stop. I had so much fun driving this car, I didn't want to get out of it at the end of the day. The loud 'whooosshhh!' which comes from the wastegate with every gear change, the madly spooling turbo, the maniac power delivery - it all gets so addictive. And the best part is, the owner of this car plans to upgrade to high-performance Koni suspension units and then increase the boost from the present 7psi to around 15psi, which is serious stuff. We hope to bring you another report on this absolutely fabulous car when the remaining mods are done. In the meanwhile, for Pune dwellers, if you happen to see a black Swift in your mirrors gaining on you very rapidly, do yourself a favour and just get out of the way...
IT JUST ANNIHILATES EVERYTHING ELSE ON THE ROAD, FLYING PAST LONG LINES OF CARS AND BUSES IN FURIOUS BURSTS OF SPEED AND ACCELERATION. IT'S MIND-BLOWING...
Forced Induction: How turbocharging works
How much air and fuel mixture you can get inside an engine's combustion chamber, and how quickly you can do it, largely determines how much power the engine makes. Like a human athlete, the better an engine inhales, the more efficient it is. And by forced induction - whether using a supercharger or a turbocharger - the aim is to compress the air before bringing it into the process of combustion, thereby increasing the volumetric efficiency of an engine.
Simply put, a turbocharger compresses air (that's going into the inlet tract of an engine) by means of a fan. This process of compression is technically referred to as 'boost,' and more boost means running more highly compressed air out of the turbo unit. Normally, the bigger the turbo, the more boost it can generate, though bigger turbos also take more time to 'spool up,' which sometimes results in what's called turbo lag. This refers to the time lag between a driver flooring the throttle, and the turbo getting up to speed and delivering more compressed air to the engine. Modern turbos, with adjustable vanes, have less lag than older turbos used to have.
Turbochargers use the exhaust gases of the engine - the higher the rate of flow of an engine's exhaust gases, the faster a turbo will spin. This is why most turbo engines produce a heady rush of power in the upper reaches of an engine's rev-range, rather than down low. That said, turbocharging does enhance the volumetric efficiency of an engine, allowing you to get more power and performance from any given engine displacement. The flip side is, turbocharged engines, because they are made to rev harder and faster than normally aspirated engines, can sometimes be more highly stressed, be more prone to wear and tear and consume more fuel.
In order to make sure a turbo only delivers as much boost as an engine can take without blowing up, boost controllers are used. An electronic boost pressure operated actuator limits the boost being delivered, by opening the wastegate when boost levels reach the predetermined PSI level. The wastegate simply 'blows off' excess pressure if it has to, thereby saving your engine from being excessively pressurised. Blow-off valves (BOVs) are also used for releasing boost pressure from the intake system. A turbocharger keeps spinning even after you let off the throttle, which means a lot of pressure can build up in the intake system. This can cause the turbines to seize and even destroy the turbo unit. BOVs mechanically open an outlet valve that relieves unnecessary build up of boost pressure. (This often results in a 'wwhhooosshhhhh!' sound coming from the engine, and signifies excess pressure being blown off.)
With some cars, the whole process of monitoring boost pressure is tied into the car's own engine management system (rather than a separate boost controller), which determines how much boost can safely be delivered to the engine. Want more boost? Well, 'chip' the engine - get an electronic chip which allows you to reprogram the ECU in the engine management system and alter fuel and ignition settings as well! y other car on our roads

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