Bugatti Chiron goes 304 mph!

Production car record smashed, Brit Andy Wallace driving - and PH has already spoken to him about it

This has to be one of the most stylish mic drops in automotive history. Bugatti has smashed the production car speed record, taking it beyond 300mph for the first time, but has also confirmed that it won't try to defend the title if anybody does manage to beat it. "We have shown several times that we built the fastest cars in the world. In future we will focus on other areas," company boss Stefan Winkelmann said in the official statement confirming the Chiron's 304.773mph, "Bugatti was the first to exceed 300mph - it's name will go down in the history books and it will stay that way forever."

Ever since the Chiron was launched - with a 261mph speed limiter - the big question has been what it could manage if let off the leash. We've had to wait nearly two years for an answer, with the record set during a week at the Ehra-Lessien test track in Germany. Fittingly, the driver was factory test pilot Andy Wallace, the British sportscar veteran whose CV highlights include having previously set production car records in both the Jaguar XJ220 and McLaren F1.

The car used for the record was in what is described by Bugatti as "near production" spec, with safety modifications and some slightly aerodynamic changes plus a taller seventh gear. It also had a 1600hp version of Bugatti's monstrous quad-turbocharged W-16, 100hp more than the regular Chiron and the same output as the recently announced Centodieci. PH believes the firm will be selling a celebratory limited edition car built to pretty much the same spec.

The record attempt took a huge amount of planning, with a team of engineers from Bugatti, Dallara - which makes the Chiron's body and developed the record car's aero kit - and Michelin, which constructed tyres capable of dealing with the astonishing forces involved in turning up to 4100 times a minute.

"I had a massive amount of trust in all the engineers and a lot of respect for them, likewise the guys from Dallara and Michelin," Wallace says, "when the project started we sat down and went through the risks, drawing a pyramid with the big ones at the bottom and trying to work out ways to eliminate them. But you can never get rid of them completely, and at the top you've still got 'sod's law' - something you just can't control. If you did this enough times it would get you. But if you trust the people you're working with, which I did 100 percent, then in the end you just do it."

To minimise the risk of failure the specially designed Pilot Cup 2 tyres were X-rayed before being fitted to the car. "Inside the tyres you've got all these thin metal strands that go radially around the edge and which are sort of equidistant from each other," Wallace explained, "on quite a lot of tyres there are one or two spots where these strands touch. It's not normally a problem, certainly not at the mandated speed limit, but when you start to go really fast with the huge gravitational force it's possible to get movement there and temperature - which you don't want."

Building up speed was done gradually, with steady-state running to help test that the car's aerodynamics were behaving as they had been predicted too; it was too big and fast for any full-size wind tunnel. The team aimed to exactly balance lift and downforce, but that still meant huge forces running through the Chiron's structure.

"Net zero downforce front and rear sounds easy, as you've got the static weight of the car pushing it down and that's more than heavy enough," Wallace explains, "but it doesn't mean the air is having no effect, it means that there is close to 2000kg on the top surface of the body trying to pick the car off the ground, and another 2000kg under the car trying to pull it back down. So two fighting forces that come to four tonnes roughly, trying to separate the car. So you've got to be absolutely sure that everything on the car is secure enough to go this fast."

Wallace says that the gyroscopic effect of the rotational speed of the tyres was another big issue. "At 200mph you can barely feel it, but at 300mph it's absolutely enormous," he says, likening it the effect of a spinning top, "it's felt mostly on the front wheels and therefore the steering, like a spinning top when it starts to move it wants to continue to move... and when you're doing 136 metres a second there's not much room to play with.

As speeds rose during testing so another sizeable challenge arrived: with the realisation that even the smallest bumps were having a big effect. "They had resurfaced one end of the track at Ehra, and once you come off the banking you're building speed on the 8.8km main straight," Wallace says, "at exactly 477km/h [277mph] the car would go from the new surface to the old surface and I got to calling this 'the jump' - a bump that you'd barely notice in a normal car, but at that speed it felt huge. If you go over that and land and there's a bit of sidewind then you lose feeling and suddenly lose confidence."

After four days on the track the Chiron had managed a peak speed of 482.5km/h - 299.8mph, tantalizingly close to the 300mph barrier - but progress seemed to have stalled with fractional changes to the car's suspension to improve stability. But Wallace remembers feeling much more confident after taking 'the jump' on what turned out to be the record run. "After it landed and had a bit of a weave about I thought it's the best it's been, the cross wind was a bit less and I just kept it pinned," he says, "the strange thing is that there's a radar speed display half way down the straight, but it's obviously never been calibrated for something so fast, I went past it and it flashed up 502km/h! I looked at my gauge and it was only doing 476km/h on the GPS, so I kept my foot in and saw it get past 490km/h, but then I was running short on room."

Slowing down at such huge speeds requires more than just dropping the anchors. "You have to do it gently," Wallace says, "you don't want to shift the aero too much and lose control of the car, even when all your instincts are telling you to stand on the brakes."

But having slowed enough for the banked turn, Wallace was the only one who realised that the record had fallen for several minutes; the Chiron had gone so fast the telemetry system relaying speed had failed to keep up.

"I saw the speed on the GPS and I was thanking everyone on the way back to the pit area over the radio," he says, "they couldn't work out why I was so happy - the fastest they'd seen was 479km/h, and we'd already gone faster than that. Then I stopped and they dived into the recording equipment on the car and looked through it, found the speed and they all went mental."

Yet if it hadn't run out of space on the world's longest test track, Wallace confirms the Chiron would have gone quicker. "The speed trace hadn't leveled out, it was still climbing," he admits. Ehra-Lessien is also just 150ft above sea level, at higher altitudes - like those on the roads used by Koenigsegg for its 277.9mph real world record in 2017 - it would encounter much less air resistance.

"A lot of people will just say 'you drove a Bugatti at 300mph, whoever you put in it could have done that' and maybe that's even true," Wallace says, "if you win at Le Mans or Daytona then there's a lot more of that being down to the driver, I'm well aware of that. But when you think about it, it's still pretty bloody cool. If somebody said to me two years ago that I was going to go over 300mph I'd have thought they were out of their mind."

This might be a record that Bugatti won't try to better, but it could still last a very long time given the huge effort the company put into setting it. Does it also mark the end of Wallace's record setting? "I can safely say I've had enough excitement to last me for a while, thanks very much," he says, "but you should never say never... Just as an aside I spent the next week after doing the run driving around really slowly and being quite happy - doing 10 or 15mph under the speed limit everywhere."

Watch the Bugatti Chiron's 304.77mph run here

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