How to develop a hypercar: GMA T.50 prototypes in-depth

16th April 2023
Ethan Jupp

The speed with which the GMA T.50 – a bleeding-edge, paradigm-shifting hypercar – has gone from styling mock-up to buttoned up and out the door is near-unprecedented. Especially considering that this is a ground-up development, with a central seat, a revolutionary active aerodynamics system, a bespoke manual transmission and an all-new V12 engine designed to rev like an F1 car and still have a warranty. There are no previous models or existing platforms to work from, so there’s no carry-over. That’s not even mentioning Covid, or the much talked-about supply chain issues that have plagued the car industry and the world at large. 


So what’s the secret to expediting the development of a hypercar from scratch? By our reckoning, and that of team GMA, there are two main factors. First, a tightly-knit, well-coordinated team, about which Prof. Gordon has been outspoken in his pride, and second: A lot of prototypes. Here at the 80th Members’ Meeting presented by Audrain Motorsport, we have no less than twelve out of the 24 made (with two in the Governor’s area being the ones in which Gordon himself and GMA CEO Philip Lee drove down).

The ten cars in the paddocks span the development process, ranging from the very earliest Ultima-based engine mule, to Pre Series 4, the final prototype to come off the production line before the customer cars go into build. GMA’s chief development engineer for the T.50, Oli Rhodes, was on hand to talk us through the incredible journey that was the development of what may well go down in history as one of the greatest supercars of all time.


There are a few stages of prototype at GMA. XP is the experimental prototype, which is followed by verification prototype (VP), then production prototype (PP) and finally pre series (PS). But it all began with an Ultima, just like the McLaren F1, the T.50’s spiritual predecessor. It even follows in the footsteps of those early Ultima mules in being named after Kings of England. George as he’s affectionately known, follows on from Albert and Edward but of course, McLaren never brought those out to tell the stories. George is very indicative of GMA’s refreshing openness about the at-times rough-edged process of honing a car from scratch, out of nothing more than bright ideas and raw materials. It’s mad to think George only went for its first shakedown in September 2020. 

“We have a lot of prototypes,” Rhodes opens. “It’s because of the time constraints – we need lots of jobs to be getting done at once. We can’t have a few going between different things. That doesn’t work with development progressing at this pace.

“We’re quite open with our prototypes. Having worked at McLaren and JLR, they’re so closed with prototypes, with horrible camo and hard panels. For our job in development it’s a nightmare. It’s why we showed the car before really getting into the programme. How open they want to be is refreshing. It puts the pressure on and it was a tight programme but I think it’s gone really well.”


Walking around George, it’s almost as if some Alien parasite has taken over an Ultima, sprouting giant nostrils with radiators, a crude-looking airbox and oil cooler.

“George was the first one,” Rhodes continues as we wander. “The first car we put the engine in after being on the dyno. In terms of powertrain, it’s pretty much everything: engine, gearbox and integrated starter generator (ISG) down the back. The airbox was 3D-printed to be exactly as it will be in the car.

“A lot of development is done virtually. The bulk of this car’s job to begin with was getting the engine, ISG and other control electronics to talk to each other. It was perfect – it was running on the dyno, so when it went in George and we built XP2, we really hit the ground running.”

We were seeing how different carbon layups would work. XP2 is going and will go quite yellow-ey, because the carbon doesn’t have the anti-UV stuff.

Oli Rhodes, GMA Chief Development Engineer

At a distance, XP2 is a huge step on from George, given it actually looks like a T.50. Get up close though, and how early it is in the programme really shows. There’s basically no interior, the carbon is a bit ragged – it’s had a life and was one of the most important cars in the process. For a start, it was also the first prototype to hit the 12,100rpm rev limit.

“XP2 was the first ‘T.50’ built,” Oli says affectionately. “It’s done all sorts of stuff. It supported continental with their traction control and ABS work early on. This one isn’t painted, partly because we were trying different tub builders and carbon suppliers. We were seeing how different carbon layups would work. XP2 is going and will go quite yellow-ey, because the carbon doesn’t have the anti-UV stuff.

“It was the first car for our aero system and the fan, with a module to test all the modes manually from the inside. At this point it had a much earlier electrical architecture. This car was probably early 2021 and it was running until late last year. At that point it became quite out of date, at which point it started on static duties – durability testing and so on. This was one of our most important prototypes.”


XP5 we know quite well here at Goodwood and, indeed, it’s what many think of when you say ‘T.50’. Why? Because this is the car that starred in the dynamic debut at Members’ Meeting in 2021. Running without cats, it gave Senna’s McLaren MP4/6 a run for its money in the noise stakes.

“Obviously it was baby blue back then but, confusingly, it’s black now,” Oli explains. “This is another step on – we have samples of architecture going on. It was still old so we weren’t nailed down on our suppliers, but this is still being used heavily for what is an old car in the programme. It started as an electrical car, in terms of making sure there’s no interference between systems.

It then became a thermal test car, at Nardo and in Abu Dhabi – that’s why it’s black. We wanted a worst case, highest-heat scenario.

The biggest exterior change we made throughout development was probably the chimneys you see here, evacuating heat from the manifolds and cats, which can reach upwards of 1,000 degrees.

Oli Rhodes, GMA Chief Development Engineer

He pops open the door revealing a sparsely-trimmed interior clad in gaffer tape and snaking wiring harnesses. He then lifts the side-mounted lid for the luggage compartment. Customer cars will get fitted luggage. XP5 had multiple electronic brains fed by and feeding myriad wires and sensors.

“This car has a lot of instrumentation going on, to monitor temperatures and other parameters in such a tight package,” Oli explains.

He then points to a slim vent running around the engine window.

“The biggest exterior change we made throughout development was probably the chimneys you see here, evacuating heat from the manifolds and cats, which can reach upwards of 1,000 degrees. It is a really enclosed engine bay, so these chimneys are a big design change. We’re a small team so we can make changes quite quick but this is probably the biggest change. We do it quite quickly and that’s been essential.”


Moving on to the next couple of prototypes, it looks like things are coming together a lot nicer. The bright, distinctly McLaren-esque orange of XP10 contrasts the subtle blue of XP9, with which 79th Members’ Meeting attendees will be familiar, as the static display car from last year. XP9 has the very interesting honour of being the first ‘factory-built’ car, at the Dunsfold facility destined to build the customer cars.

“XP9 and XP10 are where the interiors and build are really coming on, in terms of materials and how it all feels. XP9 was one of Dunsfold’s first cars, so it’s a trial for the production process for the guys. It features an early mock-up of the chimney to see how it performs. This has done a lot of electrical work with our partners, it’s done a lot less driving and it’s why it actually looks quite nice still.

“XP10 still has the prototype chimneys,” he says gesturing to the riveted-on circular vents above the engine, which look like they could have been bought from a garden centre.

“Cosworth had the car, based with us at Milbrook, for dyno and track work for software. We’ve chopped and changed what different cars are meant to be, in our timing and what we need to do. This car isn’t running an aero fan, for instance. These two are late 2021 in build, running fully early last year and are quite late in the run of 12 XPs.”

We originally had brake ducts all round, which we decided pretty swiftly that we don’t need. It reduces weight, complexity and so on.

Oli Rhodes, GMA Chief Development Engineer

We then move along to the Verification Prototypes, which are much tighter machines than the experimental prototypes. The stunning ‘Goodwood Green’ VP2 for instance, was the first T.50 to hit the public road, debuting at the McLaren F1 Owners Club 30th anniversary celebration at Lake Garda in Italy. 

"They’re certainly a step on from XPs, doing fine tuning rather than deciding on hardware,” Oli says, as we wander further down the line.

“The build is another step on, the interior is another step on, the architecture is another step on. It’s much more fine tuning and calibration. Big changes early on are finalised and by the verification prototypes, we’re tuning it. These feel massively different from the early XPs in terms of gear shifting, steering feel, damping and so on.

“VP1, which isn’t here, has been out in Sweden a lot. On standard Michelin winter tyres, it’s amazing how easy it is to drive in icey conditions. The electronics are amazing but even with everything off, it’s just so naturally well-balanced.

“The fundamentals being set so early, helped us in doing this in such a short space of time. We originally had brake ducts all round, which we decided pretty swiftly that we don’t need. It reduces weight, complexity and so on.”


Indeed, it’s a testament to how best-laid the plans were for this car, how little it’s changed fundamentally. By Oli’s reckoning, those chimneys and taking away – yes removing – brake ducts was all they really altered compared to the original model. We then move over to a familiar-looking example…

“VP5 is another one of the Cosworth cars, focused on drivability. It came to Goodwood FOS last year, it went to Abu Dhabi with XP5 for hot weather testing. It was pretty good, we basically ran all day on track in high temperatures, which is great. It prefers running hard, it can just do it all day. We did a lot of laps of Yas Marina and round there it sounded like an F1 car. There was a bit of Abu Dhabi city work, there was quite a bit of time in the mountains in the North, at altitude.”

Moving along and PP2 is looking pretty much there, albeit short of some minor details. It was the car that ‘opened’ GMA’s Highhams Park test road, before going on to do emissions homologation work. It’s also deliberately identical in spec to the launch mock-up of 2020.

“With PP2 we’re now properly trying out off-tool parts. It did our emissions work, passing Euro emissions on this car. It’s near-perfect inside minus the four-point belts. Airbag signoff came quite late, so we needed harnesses quite late into the programme. That’s the only thing that doesn’t look ‘production-ey’ at this point. We’ve got the proper chimney in it, everything’s tighter, the aero flaps are better. There’s a bit of exhaust stuff going on – a shield for the number plate. There’s also a bit of spec experimentation going on.”


Pre-series is the end of the line. With these four cars, the GMA T.50 is given the go-ahead for build and is close to being sent out into the world, to its lucky owners.

“Pre-series is, we’re pretty much done,” Oli explains. “This is the car Gordon and Dario went out in to sign it off, it’s what we’re running on track. This has been doing a lot of our damping fine-tuning – Dario’s driven it a lot.”

To get the very top speed, you use VMax Boost mode. It uses the fan to create the virtual long tail and it uses the ISG to add a bit of extra horsepower, at the very top end.

Oli Rhodes, GMA Chief Development Engineer

As much was obvious on Sunday morning at the 80th Members’ Meeting, when Dario and GMA’s chief test driver took the cars out, with the wet conditions not phasing them as they slid out of the Assembly Area, tickling the V12 up and down the revs underfoot. PS1 will also be the car journalists get to drive later this year.

We wander over to a stunning blue car at the end which hasn’t yet been seen. This is the last ever T.50 prototype – pre-series 4. It’s entirely production representative and pretty well only exists to help experiment with aesthetic specifications.

“PS4 is our very, very latest. It came out of build last week and it’s basically a production car. It’s the last prototype, serving as a trial for spec options, with the pinstriping along edges.”


In terms of titbits from the T.50s development, and the ever-elusive not-the-point headline figures? Oli did allude to a top speed of over 226mph:

“We’ve gone over 200 quite a bit. The very final number is going to be much higher. We’ll give a figure, but that figure might go up still. Officially we said the top speed is 226. That could change. To get the very top speed, you use VMax Boost mode. It uses the fan to create the virtual long tail and it uses the ISG to add a bit of extra horsepower, at the very top end.

As far as other numbers you care about in a £2million, 12,000rpm V12 hypercar? Fuel economy, of course. Being so light and slippery, it shouldn’t come as a surprise that it’s actually not too bad. I did ask if you could deploy the virtual longtail for hypermiling.

Oli explains with a smirk. “In theory yes, but it’s not a mode we’ve plumbed in. We did do a rough calculation the other day for fuel economy. It’s high 20s, low 30s probably on a run.”

You can always rely on GRR for essential consumer information.

[This interview has been edited for clarity]
Photography by Pete Summers

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