Czinger 21C beats McLaren Senna Laguna Seca lap

As the Czinger 21C edges closer to its 2023 on-sale date, the US start-up has demonstrated the incredible levels of performance it will offer by smashing the production car lap record at Laguna Seca Raceway.

Setting a 1:25.44 lap, the 919kW twin-turbocharged 2.9-litre V8 hybrid beat the previous record-holder, the McLaren Senna, by a substantial 2.18 seconds.

Driving the Czinger 21C for the record lap was US racing driver Joel Miller. The car was fitted with road-legal Michel Pilot Sport Cup 2 R tyres.

With Miller breaking the record on two previous attempts before setting the fastest lap, Czinger attributed the 21C's stunning pace to not only its big power but its low 1240kg (dry) kerb weight and its advanced aero.

"You can feel what the car is doing in the steering wheel. What the powertrain is capable of doing is absolutely mind-blowing at maximum power," said Miller.

"When setting the record at Laguna Seca, it was not by a little bit but a massive amount!"

The 21C was recently subject to a complete redesign after customers asked for the narrow concept to be widened due to lack of cabin space.

Now boasting a generous 2050mm width (12mm wider than a Bugatti Chiron), space isn't an issue, especially since the unusual 1+1 driver-ahead-of-passenger seating arrangement remains.

But after three years of testing on both road and track, engineers demanded a wider tyre for more mid-corner grip.

This forced a complete redesign of the 21C's entire exterior but there were benefits. With a wider body, stylists and engineers could optimise air-bending even further to boost downforce.

With more room, an even more sophisticated suspension arrangement could be packaged, improving handling and, thanks to revised 'active' features, the American hypercar can now alter how high it rides, benefiting downforce and handling even further.

The engine is a twin-turbocharged 2.88-litre V8 unit which, unusually for a start-up company, has been developed completely in-house. It has a redline of 11,000rpm – and generates 708kW on its own.

It's boosted by a pair of 110kW electric motors on the front axle, which offers a combined maximum output of 919kW.

A new power kit will also be offered that adds an extra 75kW, with the extra might generated from both the V8 and the hybrid's electric motors. No claims have been released how much faster that car will be.

New for the production Czinger are advanced batteries (sourced from an unnamed Formula 1 team) that can supply current and recoup energy far faster than previous batteries while still providing a pure-electric range of around 20km, possibly more.

Performance remains borderline insane. In low-downforce trim, top speed is now claimed to be 452km/h, while 0-100km/h remains an incredible 1.9 seconds and 0-300km/h takes an astonishing 13.8 secs.

Downforce has been raised to 615kg at 160km/h and a mighty 2500kg at 322km/h.

If that somehow isn't enough, Czinger says it will make a more extreme version with an even bigger aero, although it won't be road legal.

The fledgling US car brand said it will also verify its 452km/h top speed at an event in the future.

With early press drives set to begin soon, Czinger says the development of 21C should be finished before the end of this year. However, the lengthy homologation process to ensure the US hypercar is road legal in all global markets could delay first deliveries until early 2023.

Pricing for the Czinger 21C is confirmed to be $US2.05m ($A2.8m), plus local taxes.

If the Laguna Seca lap doesn't go far enough to prove that the 21C is the real deal on track, Czinger is rumoured to be readying an attempt at a production car lap record at Germany's Nurburgring.