A resposta da SSC North America às dúvidas sobre o recorde do Tuatara

O imbróglio à volta do recorde do carro mais rápido do mundo e do SSC Tuatara, o novo e alegado detentor do título, conhece novos desenvolvimentos.

Sintetizando os últimos dias, o vídeo da obtenção do recorde pelo Tuatara foi alvo de um aprofundado escrutínio, colocando em causa a obtenção desse mesmo feito — 508,73 km/h de velocidade média e um pico de 532,93 km/h, pulverizando os valores do Koenigsegg Agera RS, o detentor do recorde até agora.

As dúvidas que foram levantadas são genuínas. Desde as discrepâncias entre a velocidade providenciada pelo GPS, sobreposta às filmagens, e a velocidade real a que o Tuatara se deslocava; até às relações de caixa e diferencial (publicamente conhecidas), que impossibilitariam a obtenção dessas mesmas velocidades.

SSC North America, a resposta

Agora, finalmente, a SSC North America respondeu a todas as questões (ou quase) levantadas por estas criteriosas análises, numa longa declaração pelo seu fundador e presidente, Jerod Shelby.

No final deste artigo deixaremos a declaração original, em inglês, na sua totalidade, mas fiquemos com os pontos principais que justificam as discrepâncias e, no ponto de vista da SSC North America, esclarecem as dúvidas.

Primeiro, não há dúvidas (naturalmente) sobre a obtenção do recorde pelo responsável máximo da SSC. O Tuatara foi equipado com uma série de instrumentos e sensores da Dewetron, que mediu com precisão a velocidade do hiperdesportivo, controlado por uma média de 15 satélites ao longo das duas passagens.

Porém, num comunicado oficial distinto da Dewetron, esta refere que não chegou a validar nenhuns dados deste teste, e ninguém da Dewetron esteve presente no local onde este foi efetuado. Logo, eles não podem assegurar (para já) que os seus instrumentos e sensores estivessem corretamente calibrados, pelo que os dados, que eles ainda não tiveram acesso, sejam os mais precisos e/ou corretos. No final, eles enfatizam:

Segundo, o vídeo em si. Porque é que há tanta discrepância entre a velocidade real do carro e aquela que vemos dada pelo GPS?

De acordo com Jerod Shelby, houve enganos por parte da edição e é o próprio a admitir o erro de não terem sido meticulosos na revisão de todo o material antes de o publicarem e partilharem com o mundo.

Por exemplo, foram publicados/partilhados dois vídeos distintos a partir do cockpit — um deles pela Top Gear, outro pela própria SSC e pela Driven+ —, que adicionaram ainda mais discrepâncias e dúvidas, pois as informações observadas divergiam entre os dois.

No entanto, entre as justificações avançadas não encontramos o porquê do SSC Tuatara percorrer uma determinada distância entre dois pontos de referência a uma velocidade inferior aquelas que vemos registadas — será que partilharam o vídeo com a passagem errada? Sabemos que foram efetuadas várias tentativas e todas elas foram registadas em vídeo.

Recorde?

Será que fomos enganados? SSC Tuatara é ou não o carro mais rápido do mundo?

O SSC Tuatara foi declarado o carro mais rápido do mundo, mas será que o é mesmo? O conhecido canal Shmee150 desmonta o vídeo oficial do recorde e deixa muitas dúvidas no ar.

Fernando Gomes

Jerod Shelby diz que irão publicar, assim que possível, as imagens da tentativa onde o Tuatara atinge as velocidades declaradas, da forma mais simples possível. Aguardemos.

A outra grande questão que Jerod Shelby responde relaciona-se com as especificações do SSC Tuatara, nomeadamente as relações do diferencial e de caixa. E… surpresa, divergem daquelas que foram anunciadas originalmente, com o comunicado a referir que se trata da versão Top Speed (desconhecíamos a existência de mais versões).

Assim, a relação final (diferencial) é de 2,92, mais longa que os 3,167 que eram publicamente conhecidos. Também as duas últimas relações de caixa — 6ª e 7ª — surgem um pouco mais longas do que aquelas anunciadas anteriormente: 0,757 para a 6ª (antes era 0,784), e 0,625 para a 7ª (era 0,675).

Resultado, o atingir dos 532,93 km/h passa a ser possível de alcançar em 6ª, a relação na qual o recorde foi obtido, com uma velocidade máxima teórica de 536,5 km/h às 8800 rpm (regime máximo do motor).

O que aprendemos?

Primeiro, que o vídeo era, de facto, incorreto, o que ajuda a explicar (quase) todas as discrepâncias.

Segundo, que as especificações do Tuatara usado no teste divergiam ligeiramente daquelas que eram publicamente conhecidas, permitindo, teoricamente, alcançar as velocidades declaradas no recorde.

As explicações da Shelby SuperCars North America desfazem todas as dúvidas? Ainda não. Teremos de aguardar por novo vídeo e verificação dos dados de GPS para celebrar o Tuatara como o carro mais rápido do mundo — não há dúvidas que tem o potencial para o ser. Há agora que confirmá-lo, para lá de qualquer dúvida razoável.

O comunicado oficial da SSC North America, na íntegra

Jerod Shelby Explains World Record

On October 10, 2020, SSC North America realized a dream that was a decade in the making, when our Tuatara hypercar achieved an average top speed of 316.11 MPH.

In the days since, there has been a swirl of interest and speculation about how and whether the Tuatara had achieved that speed.

The good news: we did it, and the numbers are indeed on our side.

The bad news: only after the fact did we realize that the depiction of the speed run, in video form, had been substantially incorrect.

The following is a long explanation of what and how this happened, to the extent we now know. I hope it will serve to build trust in the SSC team, and in the exceptional feat the Tuatara has earned.‍‍

The Video

Three years ago, SSC began working with Driven Studios, a video team to document what seemed like every waking moment of the Tuatara hypercar and those who’ve created it.

They’ve since interviewed virtually every team member and consultant, captured the car in build and throughout extensive testing, and have played a key role in not only capturing, but in producing the record run on October 10 in Pahrump, Nevada. They have become a trusted partner of the SSC family.

On the big day, October 10, there were video cameras everywhere — in the cockpit, on the ground, and even secured on a helicopter a low-flying T33 to capture the car at speed.

The morning of the run, the record was achieved, we were over the moon. We kept the news under embargo until October 19, with hopes of releasing a video to accompany the press release.

On October 19, the day the news broke, we thought there were two videos that had been released — one from the cockpit, with data of the speed run overlaid, and another video of b-roll running footage. The cockpit video was shared with Top Gear, as well as on the SSC and Driven+ YouTube pages.

Somehow, there was a mixup on the editing side, and I regret to admit that the SSC team hadn’t double checked the accuracy of the video before it was released. We also hadn’t realized that not one, but two different cockpit videos existed, and were shared with the world.

Hypercar fans have quickly cried foul, and we hadn’t immediately responded, because we had not realized the inconsistencies — that there were two videos, each with inaccurate information — that had been shared. This was not our intention. Like me, the head of the production team had not initially realized these issues, and has brought on technical partners to identify the cause of the inconsistency.

At first glance, it appears that the videos released have differences in where the editors had overlaid the data logger (which displays speed), in relation to the car’s location on the run. That variance in ‘sync points’ accounts for differing records of the run.

While we had never intended for the video captured to play the role of legitimizing the run, we are regretful that the videos shared were not an accurate representation of what happened on October 10.

Driven Studios does have extensive footage of everything that transpired and is working with SSC to release the actual footage in its simplest form. We’ll share that as soon as it’s available.‍

The Car

On the day of the speed run, SSC used Dewetron equipment to track the Tuatara, and verify its speed, as measured by an average of 15 satellites across the two runs. We chose Dewetron for the sophistication of its equipment, and using that has given us confidence in the accuracy of the car’s measured speed.

People have sought additional details, which hadn’t provided in earlier press materials, and those technical specifications are listed below:

Tuatara (Top Speed Model) Tech Specs
Ratios/Speed, using the 2.92 final-drive ratio

Gear Ratios/Top Speed (Gears 1-6 have 8,800 RPM REV LIMIT)

1st Gear: 3.133 / 80.56 MPH

2nd Gear: 2.100 / 120.18 MPH

3rd Gear: 1.520 / 166.04 MPH

4th Gear: 1.172 / 215.34 MPH

5th Gear: .941 / 268.21 MPH

6th Gear: .757 / 333.4 MPH @8800 *

7th Gear: .625 / 353.33 MPH (Estimated max @7,700RPM in 7th gear – Designed as mainly an overdrive highway cruising gear)

* FYI: Cross reference validations from data log-

Oliver is travelling at 236mph when he shifts from 5th to 6th at 7,700RPM (which tracks almost exactly to the gear-ratio data) and he pushed close to the top of 6th achieving 331.1 MPH at 8,600 RPM which tracks with our theoretical of 333.4mph @ 8800 RPM.

Aerodynamic Specs:

Drag goes from 0.279 up to 0.314 at 311mph (500kph)

Car is producing approx. 770lbs of downforce at 311mph

It is calculated that car needs 1,473HP to achieve 311mph (500kph)

In order to calculate the required power the following assumptions were made:

– The rolling resistance coefficient of the tires has been obtained from the manufacturer (Michelin Pilot Sport Cup 2) declared energy class: E.

– The overall drivetrain efficiency (from crankshaft to wheel) has been set to 94%.

– The air density has been set to 1,205 kg/m3 (which is found at 20°C at sea level).

– The vehicle mass has been set to 1474 kg = 1384 kg curb weight + 90 kg driver.

Tires:

Michelin Pilot Sport Cup 2

Rear Tire Diameter / Circumference: 345/30ZR20

Normal Running Pressure = 35psi

88.5” Circumference

28.185” Diameter

WORLD RECORD RUNNING PRESSURE = 49psi

89.125” Circumference

28.38” Diameter‍

How the Speed Was Measured

The SSC team received a piece of Dewetron equipment for its use in the speed run. The SSC team was trained remotely (due to COVID) on the use of that equipment.

The Dewetron equipment includes sensors placed in the vehicle, that tracked an average of 15 satellites over the course of the Tuatara top speed run.

Two independent witnesses, not affiliated with SSC nor Dewetron, were on site to view the speeds measured by the Dewetron equipment. SSC intends to submit proof of what those witnesses had seen on the Dewetron equipment to Guinness for verification.

On October 22, Dewetron sent a letter to SSC confirming the accuracy of the equipment and speed sensor they had provided to SSC, and that letter will also be submitted to Guinness as part of application for the world top speed record.

As an additional step, SSC is in the process of submitting the Dewetron equipment and speed sensor for further analysis and verification of that equipment’s accuracy.

Fernando Gomes

Entrou no universo dos automóveis através do design, hoje expressa a sua paixão pelo automóvel na escrita.

Hiperdesportivos, Recordes, SSC North America, SSC Tuatara, V8