Gordon Murray isn't just a great engineer, he's also a superb communicator. He explains complex concepts in simple, everyday terms, and from the effortless perspective that comes from having long since mastered every important principle of performance car design. Chatting to him makes the difficult seem easy and turns the obscure apparently obvious; after a couple of hours discussing the forthcoming T50 at the headquarters of Gordon Murray Automotive near Guildford some of his nonchalance is starting to rub off, and I'm beginning to wonder why nobody has got here sooner.
But then glancing at the spec sheet for the T50 reiterates just how off-the-wall it is going to be. Any of the following facts can fairly be considered staggering on their own merits. This is a hypercar set to weigh just 980kg yet capable of carrying three people and luggage, it will be powered by a 650hp 4.0-litre naturally-aspirated V12 capable of revving to 12,100rpm, it will have a manual gearbox. Oh, and it will also boast an active aerodynamic system based around a powerful 48V electric fan. More importantly, the majority of the 100 road cars that will be produced - for £2m each - have already been sold, well before anyone has seen a physical car.
The basic details of the car were announced back in June. GMA has now released a single image of what we can expect the finished T50 to look like from the rear, a diagram indicating how its active aero system will work and - to the delight of engineering geeks, but the likely confusion of most of us - two images to illustrate the effect the fan will have when running at speed. The company has also confirmed that Racing Point will be its Formula 1 development partner, giving access to the team's wind tunnel and aerodynamic expertise.
Chatting to Murray shows just how important the project is to him, but also how much of his passion for cars and engineering has been poured into it. For many senior executives, interviews are a chance to spout platitudes and try to stick to PR-crafted points: to talk well without actually saying anything. But with Murray it's pretty much all gold. The edited transcript from my time with him is 6,800 words long; the challenge has been deciding what to leave out.
The project began as Murray started to think about an exhibition to celebrate what would be his 50th anniversary of working in the car industry, one that ended up with 42 cars, including multiple examples of the McLaren F1. "I know this will sound big headed, but I started to think that nobody had really done anything like the F1."
While hypercars had become faster and more capable in the decades that followed, very few had come close to matching the F1's remarkable 1,100kg kerbweight. But Murray also reckoned that speed and outright performance had become more important than driver involvement - and the sense of otherworldly uniqueness the F1 encapsulated.
"One of the big reasons the F1 was iconic was because everything was bespoke, there were only a very few carry over parts like the column stalks and window switches," he says, "but the aircon was from scratch, the speakers were from scratch. Even the smallest and most obscure parts were beautifully drawn and engineered. You don't do that these days because it doesn't make commercial sense."
Murray started to think about what his optimal supercar would have, with several elements coming straight from the F1. "I just thought, let's bookend it," he says, "the modern supercar started with the Miura in my view, which was quite small, lightweight and beautiful with that 4.0-litre V12. The F1 was the central milestone - very sexy, pure lightweight, nothing it didn't need. So I thought why don't we do the last, great analogue supercar?"
Weight, rather than power, was the most important goal. Murray is still disappointed that the McLaren F1 went beyond his original 1,000kg target, largely as a result of the switch to a heavier BMW engine than the Honda V10 or V12 it was originally envisaged to use, and also because the team couldn't get carbon-carbon brakes to work. The first target for the T50 was 900kg, but GMA soon realised that was too optimistic, so it was revised slightly upwards. The team has been carefully tracking the mass of every component, down to individual bolts and fasteners, and Murray is confident it will come in at 980kg.
Murray didn't even consider using turbocharging to achieve power, approaching Cosworth with a brief to create a naturally-aspirated V12. While Cosworth has also done the Aston Martin Valkyrie's hybrid-assisted V12 powerplant, the T50's 3.9-litre powerplant will be smaller, lighter and - most important to Murray - rev happier. "I didn't give Cosworth a power target, but I did say it had to be as light as possible," Murray says, "they've done a fantastic job - it's 60kg lighter than the F1 engine, which is phenomenal. I also said I want more than 12,000 revs because that is a first for a road car - although the LCC Rocket I did went to 11,500 with its Yamaha FZR engine, and they delivered on that, too."
The speed at which the engine responds was equally important. "It's the engine pick-up speed," Murray explains, "when you talk to owners of the F1 it's one of the things they love most about the car. It's schoolboy stuff - sit in the car and blip the throttle and it just goes wang-wang up and down. It's adding 10,000rpm a second, that's what people really loved."
Obviously the T50 would have to better that. "I told Cosworth that and then I got a rather facetious email from them back in January saying 'we think we've beaten your target' - 28,000 revs a second. Even as an engineer my head can't go there."
The engine will have two maps. In its normal mode it will still produce a peak of around 600hp, but will move torque down the rev range and - as Murray cheekily puts it - "runs out at what we call Ferrari revs, so around 9,500rpm. It's for when you're going to work or dropping the kids off at school." The full-fang mode then shifts everything upwards "it's the one for when you say to your mate 'do you want to hear 12,000rpm through the tunnel?'" Murray says.
While the screaming engine will be the T50's starring attraction, the active aerodynamics are the really clever bit. While Murray was pitching his explanation to the limited technical knowledge of his audience - me - the basics are actually pretty easy to understand. Murray pioneered fan-blown aerodynamics with the Brabham BT46B "fan car" in 1978 - which sucked air from beneath its skirted underside to replicate 'ground effect' aerodynamics, and which easily won the only race it ever competed in. The T50 uses a much more sophisticated system based around a 400mm 48V electric fan at the rear of the car - the one clearly visible in the rendering - with this allowing a much more aggressive diffuser shape.
"Normally diffuser air won't follow anything more than a gradient of about 7.5-degrees, it just separates," Murray explains, "so your diffuser shape has to be gentle... every designer on the planet would love to have a very aggressive diffuser like this, but the air will just say 'no thanks' and you end up with a pool of stagnant air where the diffuser has stalled, and the flow will just do its usual thing."
"The concept here is that the fan removes all of the dirty air and this boundary layer, and once that's out of the way the air has to follow that surface. At lower speeds you can generate much more downforce because the fan does the work - it's not literally sucking the car down, it's creating a much more efficient diffuser."
GMA isn't releasing peak downforce numbers yet, although Murray assures me that they are going to be impressive. But he says the system's fundamental strength isn't the size of its numbers, rather its ability to vary the amount of downforce it creates. As well as an Auto mode the T50 will have a high downforce mode, producing around 30 per cent more downforce than the base level, as well as a braking mode that will deploy two rear aerofoils and add downforce to dramatically reduce stopping distances: GMA claims the system will take 10 metres out of the T50's dropped-anchor stopping distance at 150mph.
But the system will also allow the car to run with less downforce when required. The high speed Slipstream mode will shut valves to reduce the ground effects and divert effort to suck from two inlets on the rear flanks, reducing drag and creating what Murray describes as a "virtual longtail". "Drag drops by 10 per cent, which is massive," he says, "you're no longer creating downforce that you don't need, so cruising is more efficient as well." As on the BT46B the fan also has a secondary function - extracting hot air from the engine bay.
Amazingly, Murray reckons that the weight of the fan's motor, blades, ducting and valves is less than 10kg; vastly less than the mass added by the hydraulic actuators for a conventional adjustable wing.
There will also be what Murray terms push to pass - officially known as Vmax mode - which adds power to the engine through the 48V starter-generator required for the fan and electric aircon compressor. That will give about 30hp which, along with some ram effect from the engine's high-level intake, means a peak of around 700hp. Not bad for a car that isn't designed for a headline grabbing power figure.
The active fan and ability to adjust downforce has also allowed the T50 to do without the weight and complexity of an active suspension system. There is no need for helper springs or even switchable shock absorbers, with double wishbones and coil springs at each corner, as well as passive dampers. "One of the problems with the F1 was that it was quite softly sprung and at higher speeds the downforce just eats up all the suspension travel," Murray says. His personal Alpine A110 was pulled to pieces so the GMA team could benchmark its dampers - "they're passive and it's the best ride-handling compromise out there at the moment. It used to be the Evora, but the Alpine is better."
Like most supercars of its era the McLaren F1 didn't have power steering; the T50 will have low-speed assistance from a 12V electrical motor, but this will fade out above a certain speed to improve feel and feedback. "It's basically parking assist," Murray says.
The manual gearbox is another huge difference from other contemporary hypercars; an ideological as well as a mechanical one according to Murray. "This isn't a car that's designed for lap times. It will obviously be fast anywhere you choose to take it, but that really isn't the point of it," Murray says. His original plan was to use a sequential manual box, but buyers were soon lobbying for a more conventional H-pattern with X-Trac charged with developing it. "A lot of people said please make it a manual, that's one of the things they liked the most about the F1," he says, "if you want the purest interface, the clutch pedal and H pattern is still the best, there's nothing better."
There will be a non-manual version, with plans for a limited-to-25 track-only version that will have a sequential 'box. "That's going to have three times the downforce of the road car, and at the speeds you're going to be doing around a track it doesn't make sense to be worrying about gears." The track car will also have fixed wings and a much simpler algorithm for the fan - basically giving maximum downforce most of the time.
Perhaps surprisingly, Murray says the manual-only gearbox has barely been an issue with potential buyers, despite 40 per cent of customers being under the age of 45. "We've only had one person who asked to have the track car gearbox on the road car, which would be very difficult because of the electrical architecture," Murray says. Existing McLaren F1 owners are also heavily represented in those who have raised their hands.
"Why do you want one of these if you've already got an F1?" Murray asks, rhetorically. "But you have to think about the practicality. I had an F1 for a while and when they start getting up to $10m, $15m, now even $25m you're not sure about taking them out in the wet and sliding them around to show your friends what fun it is... I'd be very surprised if there were more than a handful of F1s in daily use now, even monthly use."
"The T50 will deliver everything the F1 delivers from a driving experience, but better," Murray says, "it makes perfect sense - they've still got the F1 and it's a great investment, but here's one for a fraction of the price they can go and thrash to death. Several buyers have told me that's exactly what they are going to do with it." A sentiment we can all get behind.