The Koenigsegg Jesko Has An Amazing Engine
The Koenigsegg Jesko 5.0-liter twin-turbo V8. (All images: Koenigsegg)
The Koenigsegg Jesko, which was introduced at the 2019 Geneva International Motor Show, is not your ordinary automobile, even in the context of Koenigsegg, which is well known for making extraordinary supercars.
After all, the car is named after Jesko von Koenigsegg, father of Christian von Koenigsegg, who established the Swedish boutique builder of exquisite machines in 1994. Boutique? Plans call for the production of 125 Jeskos, all of which have been spoken for. (Other models through the years had numbers like these: Agera RS, 25 vehicles; Regera, 80.)
The Jesko’s aero design provides downforce of 800 kg at 250 kmph and 1,000 kg at 275 kmph.
The Jesko, which is manufactured at the Koenigsegg plant in Ängelholm, Sweden, is based on an all-new carbon fiber and aluminum sandwich monocoque; the monocoque has a torsional rigidity of 65,000 Nm/degree. Material reinforcement is provided through the use of Dyneema, a ultra-high molecular weight polyethylene material from Royal DSM that is claimed to be “the world’s strongest fiber” and a supplement to carbon fibers in a composite matrix that lends the ability to handle impact forces greater than what can be accommodated by a carbon fiber-based composite alone. What’s more, it also provides ductility, which presumably is helpful in creating the design of the car, about which Joachim Nordwall, design director, said, “We adopted a ‘shrinkwrap’ approach to skinning this car, using crisp angles and lines to eliminate empty spaces and make the design as effective as possible.”
One of the key considerations in the design of the vehicle—which is street legal, although fully track capable—is providing aerodynamic downforce to keep the rubber on the road, as the car is expected to run at a speed in excess of 300 mph (483 kmph). According to Koenigsegg, Jesko provides downforce of 800 kg at 250 kmph (1,764 lb/155 mph); 1,000 kg at 275 kmph (2,204 lb/171 mph). The maximum is 1,400 kg (3,086 lb). (It may be interesting to note that even the design of the side mirrors contributes to 20 kg (44 lb) of downforce.)
It is based on an aluminum and composite monocoque.
But speaking of weight, it isn’t just in terms of the chassis for which mass matters; the powertrain, engine and transmission, were also looked at from the point of view of weight-savings. (The vehicle has a curb weight of 1,420 kg, or 3,124 lb.)
The car features a 5.0-liter twin-turbo V8 that produces 1,280 hp on standard gasoline (and 1,600 hp on E85 biofuel).
The engine features a flat-plane 180-degree crankshaft designed-in house that is said to be the “world’s lightest production V8 crankshaft”: 12.5 kg (27.5 lb.). It is machined for Koenigsegg by a Swedish supplier from a billet of Uddeholm Dievar steel, a chromium-molybdenum-vanadium alloyed hot work tool steel that is typically used for applications like diecasting, forging and extrusion, which goes to say that it is highly capable in an application in a high-performance engine. The flat-plane design is used to provide even firing across the engine banks. However, there is an issue related to vibration that can occur, so Dr. Thomas Johansson, the man responsible for Koenigsegg engine design, designed specific connecting rods for the engine.
The connecting rods are produced with Swedish steel and each, including bolts, weighs 540 grams, which is comparable to the mass of con rods produced for other Koenigsegg vehicles—with titanium.
The Jesko has an adaptive active rear steering system, rear triplex dampers, and as evident, abundance of structural carbon fiber.
In addition, another vibration countermeasure was the design of a new piston. The piston has a curved face. This configuration means there is reduced peak pressure in the combustion chamber but high average pressure. There is a ceramic coating on the face of the piston to prevent hot spots. The piston is also light, weighing just 290 grams. This is said to be important due to long strokes and a rev limit of 8,500 rpm.
The head—cast by Grainger and Worrall, a supplier to Formula One engine builders—is designed with a “tumble” valve on the intake side. The purpose of this is to increase the amount of turbulent air going into the engine, as it provides a faster burn rate and results in more effective combustion. (The engine features an individual in-cylinder pressure sensor system so as to monitor and operate each cylinder at maximum efficiency.)
And while on the subject of air: there is a small electric compressor that draws air from a 20-liter carbon fiber tank and feeds it to the twin turbochargers. The air injection system has a timed 20-bar burst of air into the turbo housing such that the two turbos are pre-spooked, thereby eliminating turbo lag and improving overall turbo response.
Additionally, the air injection system is used to help get the catalytic converters up to temperature at engine startup.
While there is an increasing number of engines that are doubling up on the fuel injectors per cylinder, Koenigsegg claims to be the first, in serial production, to do them one better: three injectors per cylinder. In addition to the two per cylinder mounted on the fuel rail, the third one is in the intake plenum. This positioning results in better fuel aeration for a cooler cylinder, cleaner combustion and reduced engine strain when it is operating full-on.
(The V8 is mated to a Koenigsegg designed and manufactured 9-speed multi-clutch transmission. It is called the Light Speed Transmission because, well, it is light. Including all fluids, it weighs just 90 kg. According to Koenigsegg, a typical dual-clutch gearbox can weigh up to 140 kg. But more than dual-clutches, the LST has a “multi-clutch” design. The transmission is controlled with what is called “Ultimate Power on Demand” (UPOD) technology, which allows the selection of the optimum gear for the conditions, whether this is a single upshift or down shift or shifting from 7th to 4th. The UPOD takes into account engine speed and vehicle speed to make the determination of what gear to shift to; the use of multiple clutches makes the physical adjustment possible.)
Koenigsegg Jesko Specs
Total length: 4,610 mm (181.5 in.)
Total width: 2,030 mm (79.9 inches)
Total height: 1,210 mm (47.6 inches)
Ride Height: 70-100 mm (2.7-3.9 in.) front, 75-100 mm (2.9-3.9 in.) rear
Front lifting system activated: +50 mm (1.9 in.)
Wheelbase: 2,700 mm (106 in.)
Fuel capacity: 72 liters (19 gallons)
Luggage compartments: 100 liters (3.5 cubic feet) front, 50 liters (1.7 cubic feet) rear
Dry weight: 1,320 kg (2,910 lb.)
Curb weight: 1,420 kg (3,130 lb.)
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