Orignal Link >>http://pistonheads.com/doc.asp?c=47&i=14806 Although top speed is irrelevant in the real world, the big number is like a god to supercar enthusiasts and owners alike. So when the 806bhp Koenigsegg CCR snatched the Guinness Book of Records Fastest Production car accolade with an accredited top speed of 387.866kph at Nardo in early 2005, that really put the small Swedish supercar maker on the map. Bespoke enhancements CCX is a next generation car with many significant changes over the CC8S and CCR that went before, but as with all Koenigsegg models, the main tub of the 1,108kg production CCX is made from carbon-fibre with lightweight sandwich reinforcement. A key feature is the removable carbon-fibre roof panel which stows neatly in the front luggage compartment. The underbody is flat with venturi tunnels, a front air splitter and rear diffusers, and the carbon-fibre rear wing is an option that provides some downforce at high speed. Even without it there is 60kg of downforce over the front axle and 65kg over the rear axle at 125mph. Drag coefficient is 0.3 with a frontal area of 1.867sq. m. The thing that bowls most onlookers over is the unique way the door operate. Now that people are used to seeing gull-wing and even butterfly doors, Koenigsegg’s rotating door is so different it does make them stop and take notice. The Koenigsegg approach to cabin design is the result of a clean sheet of paper, so you will find no major manufacturer's switches or dials here. The big rev counter and digital LCD readout below are made by Stack and come straight from the racecar catalogue. However, around it, every piece of trim, every switch and every dial is specially made for the car, which adds to the bespoke ambience of the interior. As the US is still the biggest potential single market for supercars, it was important that Koenigsegg obtained 50-State certification for the car. The result of this work is the CCX you see here. The X by the way is the Roman numeral and signifies ten years of the Koenigsegg company. Engine updates Although its output numbers are the same as the CCR, the CCX has had a few changes made to the motor to help it meet California emissions legislation. These include new cylinder heads with larger valve area and optimised ports, two small rather than one large injectors per cylinder, new camshaft profiles, new carbon-fibre intake plenum, revised ECU, updated fuel system. Finally the redesigned exhaust system brings the catalytic converters closer to the engine for faster light-off. As before, a pair of Rotrex centrifugal superchargers provide 1.2 bar of boost with a maximum of 1.35 bar on over-boost. Amazingly, the 4.7 litre 32-valve V8 behaves more like an 8.0 litre atmospheric motor with tons of torque from the word go and a rabid lust for revs. And all on normal 91 octane US pump fuel. Thanks to Koenigsegg’s patented dual throttle body equipped response system, there is absolutely no feeling of lag or disconnection from the action. The motor answers a call for power with an immediacy and urgency that would do a race-tuned normally-aspirated engine proud. This is all the more amazing when you consider that the compression ratio is just 8.2:1. With a bore and stroke of 90.4 x 90.7mm the 4,712cc V8 motor is almost exactly square, and it revs hard and fast. Like the CCR, the US 50-State legal CCX makes 806bhp at 6,900rpm and 678 lb-ft of torque at 5,700rpm. The rev limiter comes in at 7,500rpm but the motor will take 8,500rpm. The CCX leaves the line hard with the kind of kidney punch every speed junkie craves. Sixty-two mph comes up in 3.2 sec and top speed on the flat is 254-plus mph. At the other end of the scale, it will potter around town all day in fourth with the tacho needle barely hovering above 1,000rpm. The dark side However, its darker side relishes life closer to the red-line. So when you reach 6,000rpm the first time and think that this is a mighty fast car, the CCX is just limbering up. Keep going and the further lunge forward between 6,000 and 8,000rpm is intoxicating. The soundtrack that accompanies this brutal forward thrust reminds you that Thor, the god of thunder, was Scandinavian. Our drives on both the airfield test track and public roads were done with the roof off and the unfiltered soundtrack was quite spectacular. Bass rich, the sound is not quite NASCAR deep but it has strong bent crank V8 undertones. The induction noise is unique to this car and while it is muffled slightly by the superchargers, it still produces a powerful induction roar above the bellow of the cylinders firing. The CIMA six-speed gearbox does not like snap shifts except in the same plane so, for best results with shifts across the gate, you need to let the spring-loading to the three-four plane do its work. The race-grade clutch is heavy on first application from a standstill but because take-up is so smooth and progressive, you cease to notice its engagement weight on the fly. The standard issue steel brakes are massive 362 x 32mm AP Racing vented discs and six-pot calipers and using them in anger washes off speed like a jet fighter deploying its drogue chute. If you need even more stopping power and durability for track use, 380 x 34mm with eight-pot calipers are an option. They are expensive but they save a whopping 40kg in unsprung weight. The Holy Grail of renowned test driver and engineer Loris Bicocchi’s suspension development mantra is that ride and handling are not mutually exclusive. Therefore, all the cars he develops have a good ride as well as brilliant handling. On country roads, the CCX impressed with its good secondary ride over short, sharp bumps and total lack of bump steer. Even though you feel the bumps there is no adverse reaction through the steering, which itself is pin sharp in reacting to driver inputs. Robust Supercars as a genre have a reputation for being fragile, but so far the CCX prototype has been totally reliable and nothing major has broken. It has been thrashed (and crashed!) by BBC Top Gear’s Stig on its track at Dunsfold, where it set the fastest ever lap time. It has also lapped a cold Nürburgring Nordschliefe in 7 min 34 sec in the hands of Sport Auto Magazine and been subjected to continuous abuse in the hands of Loris Bicocchi during development work. “Even though the car is light, everything is over-engineered,” said company founder Christian von Koenigsegg. “The people who pay the €525,000 for my cars should have a totally satisfactory ownership experience, even if they use their cars hard on the track.” Amen to that.