Currently reading: UK start-up reveals 500bhp Rolls-Royce Corniche restomod

Halycon's debut model uses an electrical architecture and software developed in-house

Guildford-based start-up Halcyon has revealed a new restomod based on the Rolls-Royce Corniche and Silver Shadow, converting the classic cruisers to electric power using an architecture developed entirely in-house.

Based on the later rubber-bumpered models, it swaps the original circa-200bhp 6.75-litre V8 for a rear-mounted electric motor with significantly more poke. Standard Range examples get around 400bhp, while the Long Range is boosted to some 500bhp.

Under the bonnet lies a large battery pack constructed in the same vee shape as the original powerplant; at the rear end sits a second unit that replaces the petrol tank. This set-up is said to preserve both the packaging and the weight distribution of the original car, tipping the scales at the same 2.2 tonnes (split 53:47, front to rear).

Standard Range cars are claimed by Halcyon to deliver a range of around 200-250 miles, while the Long Range manages 250-300 miles.

The system runs on 800V electricals, allowing charge rates of up to 230kW. This yields a 10-80% refill in around 40 minutes.

The entire electrical package and the software on which it runs was developed and supplied by Halcyon’s sister company, Evice. This, according to the companies’ co-founder and CEO Matthew Pearson, gave much greater freedom to develop an ideal technical solution for the Silver Shadow platform.

Halcyon Rolls-Royce Corniche interior

There are three driving modes to maximise the bandwidth of the Halcyon Corniche’s capabilities, named Drive, Spirited and Touring. Pearson explained: “In Spirited you’ll get a slightly more responsive throttle, slightly firmer dampers both passively and actively; and in Touring, if you’re on a motorway, enable cruise control and the dampers will slack right off – you’ll just be on a floating cloud.” Because the entire electrical package is the company’s own development, rather than a series of off-the-shelf components, “we can be quite precise with how we want the car to behave”. 

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In addition to technical changes, the Halcyon Rolls-Royce gets a new interior that aims to strike a balance between a traditional look and offering modern conveniences. For example, it has wireless Apple CarPlay connectivity and a reversing camera, but the screen hosting these features can also be hidden at the touch of a button. The instrument panel retains analogue dials too, displaying key information such as the remaining range and battery charge level. Halcyon also promises material quality and personalisation on a par with brand-new Rolls-Royces.

It will build a total of 60 cars, offering the conversion on both the Corniche coupé and convertible and the Silver Shadow saloon. Prices start at around £400,000 excluding the cost of a donor car (around £50,000 for a tidy example) and taxes.

The Corniche and Silver Shadow were chosen to launch the Halycon and Evice businesses because of both the models’ appeal and their platform’s technical attributes, said Pearson. He explained: “There are earlier cars that were options, but their body-on-frame [constructions] do not tolerate the degree [of modification or performance]; the electric powertrain just simply doesn’t have an end result for what we were looking for.”

Pearson added that the Silver Shadow’s unibody construction meant it was one of the most torsionally stiff cars of its period, so is “really well suited to the sort of things that we’re expecting”. 

Halcyon Rolls-Royce Corniche rear

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There was also a commercial argument in favour of the Roller. “The thing that we absolutely wanted was to do it properly, and to give us the capacity to develop technologies that can serve other purposes,” said Pearson. We needed to do that by building a car for which clients are willing to spend what we want to charge.”

The allure of contemporaries such as the Citroën DS would not have matched up to the high price that Halcyon is asking for its Silver Shadow, suggested Pearson, so were considered a no-go.

The first Halcyon cars are earmarked for delivery next year. In the meantime, Evice will begin pitching its technologies and services to firms in the automotive, marine and commercial vehicle sectors. It has already developed an electric test mule for Land Rover specialist Twisted and will commence a feasibility study on that car in the coming months.

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Charlie Martin

Charlie Martin Autocar
Title: Staff Writer

As part of Autocar’s news desk, Charlie plays a key role in the title’s coverage of new car launches and industry events. He’s also a regular contributor to its social media channels, creating content for Instagram, Tiktok, Facebook and Twitter.

Charlie joined Autocar in July 2022 after a nine-month stint as an apprentice with sister publication What Car?, during which he acquired his gold-standard NCTJ diploma with the Press Association.

He is the proud owner of a Mk4 Mazda MX-5 but still feels pangs of guilt over selling his first car, a Fiat Panda 100HP.

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Bob Cholmondeley 3 September 2025

Who needs an electric motor in old Roller? John Dodds had it right, with his Meteor, later Merlin, emgined The Beast.

289 3 September 2025

Yet another 'bunch of EV dreamer's' who will go to the wall owing millions.

"Based on the later rubber bumpered model" -clearly not according to the pictures! with 4-500 BHP.....why on earth would a Corniche need this amount of power....this is not what a Corniche is about?

I have driven many Corniches in my lifetime, and "torsional ridgidety" was never an impression that I observed amongst it's attributes !!!

And all this before we cover the tricky issue of the pricing. Madness.

Gavster11 3 September 2025

£450,000 (including the donor car) isn't a stratospheric asking price? That's about the price of a new Phantom....

Marc 3 September 2025

But is 450k too much to drive around looking like a disgraced 70s entertainer?

Pierre 3 September 2025

Comment of the week!