It’s easy to focus on the numbers when it comes to a new car from Koenigsegg. The Koenigsegg Jesko, its Geneva car this year, claims 1,600 horsepower, 1,000 kilos of downforce at speed, and a nine-speed transmission with seven clutches. But I’m more interested in its kind of anti-lag.
The ever-wonderful Christian von Koenigsegg (the car is named after his dad) points out that this is meant to be a global car, with airbags designed for meeting U.S. safety standards, and hardware to heat up the catalytic converters to help with passing tighter emissions regulations around the world. But it’s a supercar so it has to be more powerful, and one of the things it has is bigger turbos on the 8,500 RPM 5.0-liter V8, now with a 180-degree flat-plane crankshaft, as noted in the car’s press release.
While I’m here on specs let me lay out the key stuff that Koenigsegg claims:
- Curb weight: 3,130 lbs (1,420 kg)
- HP: 1,280 on 91 octane, 1,600 on E85
- Torque: 1,106 lb-ft (1,500 Nm) at 5100 RPM
- Downforce: 800 kg at 155 mph, 1,000 kg at 170 mph, 1400 kg “maximum”
But bigger turbos mean big lag, and big lag in a fast car means a car can quickly become a widowmaker, as was the case with the original Porsche 911 Turbo.
Certainly, a company like Koenigsegg could say, oh yeah, turbo lag is exciting. This is meant to be a thrilling car, with a big wing and big scoops and a ludicrous top speed. But that’s not how Koenigsegg does things, opting for more weird tech solutions to the little problems of supercardom. In this case, that means an auxiliary air tank that spools up the turbos when the engine itself wouldn’t be enough.
Christian himself explains how it works in this video from APEX ONE, at around 2:50 in:
The turbo system is new on the car. It’s a bigger turbo than we’ve had before. This has the benefit of reducing the backpressure, which gives more power. It has the benefit of being able to supply more airflow at high boost. But it has the negative effect of reacting slower in transitions because you have more inertia to overcome in the impeller and the turbine.
So we came up with a system where we have a 20-liter carbon fiber tank onboard, which is pressurized by a small electrical compressor, and then we strategically inject air in the turbo system to help spool up the turbos as quickly as possible.
We’re talking about less than a second or so bursts in transitions, but it makes the turbo feel like a really small turbo. Also it helps a big turbine to create boost at lower airflows than it normally can.
This is what you would identify as a form of anti-lag, normally done by retarding ignition timing so that you actually combust some air and fuel down the exhaust into the turbo itself. That way of doing things is incredibly hard on your turbo and exhaust manifold, though, and isn’t the kind of thing that works well for a street car. It’s also, you know, ear-shatteringly loud. Cool for a rally in the woods, not so cool for rolling up to the casino in Monte Carlo.
In any case, this is a fun new demonstration of what Koenigsegg is and can be, a high-tech kind of car from a very, very small manufacturer, one working a little bit smarter than it needs to.