How Koenigsegg built the fastest engine in history

Koenigsegg

The 5.1-liter twin-turbo V8 that powers the Koenigsegg Jesko might just be the fastest engine ever installed in a production car. But according to founder Christian von Koenigsegg, that wasn’t even a goal the engineers had in mind when they made this engine.

The “engine pickup speed” is the speed at which an unloaded internal combustion engine can gain in rpm. It’s a statistic that most automakers don’t bother to release. The last time the topic was brought up was over a decade ago, with the glorious Yamaha-built V-10 powering the Lexus LFA, a car that required a digital tachometer to keep up with its free-revving engine. , which could go from idle to 9,000 rpm in 0.6 seconds, a pickup speed of 15,000 rpm per second.

Today, data from Koenigsegg shows the company’s latest V-8 has an average pickup speed of 31,700 rpm per second, with the pickup spike registering at an almost unbelievable level. 46,000 rpm per second in the middle of the engine speed range. It’s wild, and as far as we can judge, an all-time record for road car engines.

jesko engine

Koenigsegg

The funny thing is that the company didn’t even consider the pickup speed capability of its new engine until Gordon Murray Automotive started talking about the statistic in August 2020. The British supercar startup , founded by (and named after) the man behind the McLaren F1, claimed that its naturally aspirated 4.0-liter V-12, built by Cosworth, has a recovery speed of 28,400 rpm per second, from idle to red line in 0.3 seconds.

But when Koenigsegg’s engineers examined their own engine’s revving capability, they found the Jesko powertrain was beating GMA’s Cosworth V-12. “Gordon Murray’s car is the only benchmark we’ve heard of,” said Christian von Koenigsegg Road & Track. “As they were very proud of it, an engineer came to me and said, ‘Christian, you know we’re much better than this.’ I said, really? If it’s such an important thing, maybe we should mention it.

According to von Koenigsegg, the deciding factor that allows the Jesko engine to run faster than the GMA is not in the engine is the transmission. Murray’s car uses a custom six-speed manual transmission built by Xtrac, with a thin titanium disc in place of a conventional flywheel and a triple-disc clutch. This setup allows for such rapid engine response that GMA had to install complex RPM matching software to allow smoother driving.

jesko engine

Koenigsegg

But the Jesko has no flywheel, no clutch, and no synchronizer in its transmission. The gearbox, called Lightspeed, has nine forward gears; it is integrated into the engine block, weighs 198 pounds and can withstand over 1,100 lb-ft of torque. Instead of a conventional clutch mechanism between engine and transmission, the Lightspeed gearbox has seven wet clutches inside its aluminum housing, plus an eighth for the electronically controlled differential.

The highly unconventional drivetrain design allows for capabilities never seen before in road cars. In the Jesko, you can switch from any gear directly to any other gear, almost instantly. Double pressing the gear selector automatically shifts you down to the lowest possible gear, regardless of your speed, for maximum acceleration.

Due to the way the gearbox works, it is also not necessary to match the speed. “We can use the gearbox to force the engine to shift faster, which you can’t do with the synchros,” says von Koenigsegg. “On top of that, with nine gears you have super short gears. It’s really cool, a tight gear like a motorcycle. I had high expectations, but it really blew me away in terms of the level of engagement and response, how well he does exactly what you want immediately.

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Von Koenigsegg says his team never focused on the pickup speed of the engine. Removing the flywheel and clutch helped make the transmission lighter and more compact – the insane ability to crank up the revs was a marginal benefit. “It’s pretty wild,” says von Koenigsegg. “I have never seen an engine without a flywheel, but it worked perfectly, first in simulation, but also in reality. “

The GMA T.50 is known to be one of the last naturally aspirated supercars available today. Murray is fiercely against turbochargers – he’s once likened the responsiveness of turbo engines to “watching the paint dry.” The Koenigsegg twin-turbo V8 clearly doesn’t suffer from this characteristic, and the man behind the brand was quick to explain why.

“Turbos have no impact on the responsiveness of an engine itself,” said von Koenigsegg. “It’s more that turbo engines tend to have heavier components inside. Of course, if you have huge turbos, you have a lag in your boost, which is different from the pickup speed of the engine.

jesko engine

Mate Petrány

Von Koenigsegg admits that under very specific driving conditions you might experience a gradual build-up of boost in the Jesko. Cruising in ninth gear at 1700 rpm? Yes, if you put it on the ground you won’t feel most of the momentum until around 3000 RPM. “But if you use the shifter instead and go from 1,700 RPM to 7,000 RPM in an instant, there’s no delay. You can certainly drive it with the feeling of not having any turbo at all, at full power all the time. “

The result seems to have surprised the founder of the Swedish supercar company. “We expected a superb response, with no flywheel or clutch, and it looks like it’s faster than anything we’ve seen before. The sensation is electrifyingly rapid. I continue to use the word “synaptic”. It’s like, you think about the diet, you got it. There is no lag. It’s right there, immediately. It’s really cool.”

In neutral, the Jesko V-8 is limited to 7,800 rpm, which drops to 8,500 rpm in gear. To ensure maximum punch at all times, Koenigsegg added a patent-pending air injection system, using a small electric compressor to fire precisely timed 290 psi bursts of air directly into the turbochargers, the pre -winding to eliminate the lag.

jesko engine

Koenigsegg

The engine that powers the Jesko is actually an evolution of the Agera RS’s V-8. Displacing just under 5.1 liters, it’s a flat crank design with dry-sump lubrication. Being a long-stroke engine, the Koenigsegg team had to give some serious thought to the vibrations while hitting that 8,500rpm redline. The connecting rods are Swedish alloy steel, not the titanium found in the Agera RS, but weighing just 1.19 pounds each, the new material offered increased strength without a weight penalty. The pistons weigh 0.63 pounds each, with a ceramic coating that prevents the development of hot spots under heavy engine loads. Each cylinder receives a pressure sensor and two fuel injectors; a third injector is located in the intake plenum above each cylinder. On gasoline, the Jesko V-8 develops 1280 horsepower; go to E85, and that number goes to 1600.

Koenigsegg is one of the most extreme examples of an automobile manufacturer on the planet. The multi-million dollar hypercars leaving the brand’s facilities have outrageous engineering solutions not seen in any other vehicle. This was only the first part of our long conversation with von Koenigsegg – stay tuned for more in the days to come.

jesko engine

Koenigsegg


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