How Koenigsegg Built the Fastest-Revving Engine in Production Car History

Whether you are a petrol head or not this has some very interesting technical features about transmission design as well as the straight horsepower figures etc. It was published in Road & Track magazine and written BY MÁTÉ PETRÁNY on DEC 2, 2021.  Apart from $3million supercars I feel there are lessons in transmission technology that could be applied to standard mass produced production vehicles.

The 5.1-liter twin-turbo V-8 that powers the Koenigsegg Jesko might just be the fastest-revving engine ever installed in a production road car. But according to founder Christian von Koenigsegg, that wasn’t even a goal that engineers had in mind when they made this engine.

“Engine pickup speed” is the rate at which an unloaded internal combustion engine can gain rpm. It’s a stat that most automakers don’t care to publish. The last time the topic came up, it was over a decade ago, with the glorious Yamaha-built V-10 that powered the Lexus LFA—a car that required a digital tachometer to keep up with its free-revving engine, which could go from idle to 9000 rpm in 0.6 seconds, a pickup speed of 15,000 rpm per second.

Today, Koenigsegg’s data shows that the company’s latest V-8 has an average pickup speed of 31,700 rpm per second, with peak pickup registering at a nearly unbelievable 46,000 rpm per second in the middle of the engine’s rev range. That’s wild, and as far as we can tell, an all-time record for road car engines.

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

But when Koenigsegg engineers looked into their own engine’s revving ability, they found that the Jesko powerplant beat GMA’s Cosworth V-12. “The Gordon Murray car is the only reference we’ve heard of,” Christian von Koenigsegg told Road & Track. “Since they were very proud of that, an engineer came to me and said, ‘Christian, you know we are much better than that.’ I said, really? If it’s such a big thing, maybe we should mention it.”

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

But the Jesko has no flywheel, no clutch, and no synchronizers in its transmission. The gearbox, dubbed Lightspeed, has nine forward gears; it’s integrated with the engine block, weighs 198 pounds, and can handle more than 1100 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 wildly unconventional transmission design allows for capabilities never seen before in road cars. In the Jesko, you can shift from any gear directly into any other gear, nearly instantaneously. A double-tap of the gear selector automatically downshifts you to the lowest possible gear at whatever speed you're traveling, for maximum acceleration.

Because of how the gearbox works, there’s no need for rev-matching, either. “We can use the gearbox to force the engine to change rpm quicker, which you cannot do with synchros,” von Koenigsegg says. “On top of that, with nine gears, you have super short ratios. It’s really nice, motorcycle-like tight gearing. I had high expectations, but it really blew my mind in terms of engagement level and reaction, how it just does exactly what you want immediately.”

Von Koenigsegg says his team was never focused on engine pickup speed. Removing the flywheel and clutch helped to make the drivetrain lighter and more compact—the crazy rev-building ability was a fringe benefit. “It’s pretty wild,” says von Koenigsegg. “I’ve never seen an engine with no flywheel, but it just worked perfectly—first in simulation, but then also in reality.”

The GMA T.50 is famously one of the last naturally aspirated supercars available today. Murray is staunchly against turbochargers—he once compared the responsiveness of turbo engines to “watching paint dry.” The Koenigsegg twin-turbo V-8 clearly doesn’t suffer from this characteristic, and the man behind the brand was eager to explain why.

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

Von Koenigsegg admits that, under very specific driving conditions, you might experience a gradual buildup of boost in the Jesko. Cruising in ninth gear at 1700 rpm? Yeah, if you floor it, you won’t feel most of the boost until around 3000 rpm. “But if you instead use the gear lever and go from 1700 rpm to 7000 rpm in an instant, there’s no delay whatsoever. You can definitely drive it with the sense of having no turbos at all, full power all the time.”

The result seems to have surprised the Swedish supercar company founder. “We expected a superb response, having no flywheel or clutch, and it seems like it’s faster than anything else we know of. The sensation is electrifyingly fast. I keep using the word ‘synaptic.’ It’s like, you think about revs, you have it. There’s no lag. It’s just there, immediately. It’s very cool.”

In neutral, the Jesko V-8 is limited to 7800 rpm, which raises to 8500 rpm in gear. The automaker contemplated adding an air injection system, using a small electric compressor to fire precisely-timed 290-psi bursts of air directly into the turbochargers, pre-spooling them to eliminate lag, but in testing it proved to be unnecessary.

The engine that powers the Jesko is actually an evolution of the V-8 in the Agera RS. Displacing a touch less than 5.1 liters, it’s a flat-plane-crank design with dry sump lubrication. Being a long-stroke engine, the Koenigsegg team had to think hard about vibrations while reaching to that 8500-rpm redline. The connecting rods are Swedish steel alloy, not the titanium found in the Agera RS—but weighing just 1.19 pounds apiece, the new material offered added strength without a weight penalty. The pistons weigh 0.63 pounds each, with a ceramic coating that prevents hot spots from developing under large engine loads. Each cylinder gets a pressure sensor and two fuel injectors; a third injector sits in the intake plenum above each cylinder. On pump gas, the Jesko V-8 makes 1280 horsepower; switch to E85, and that number rises to 1600.

Koenigsegg is one of the most extreme examples of an automaker on the planet. The multi-million dollar hypercars that leave the brand's facilities possess outrageous engineering solutions not seen in any other vehicles. This was just the first part of our extensive conversation with von Koenigsegg—stay tuned for more in future days.

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