The Toyota TF109 was the Japanese giant\u2019s final F1 car. After a seven year spell on the grid, as the global financial crisis hit, it ended its programme, despite having a 2010 car fully developed and ready to race.<\/p>\n
In many ways, its departure marked the end of the era of excess, where teams would spend with wild abandon. Toyota had two state-of-the-art wind tunnels at its Cologne base running 24\/7, which were constantly fed with fresh new ideas.<\/p>\n
During development of the TF109, one such idea came from Sammy Diasinos. A young Australian CFD engineer, he\u2019d landed the job while completing his PhD in aerodynamics. More specifically, on the interaction between a front wing and the wheel of a car. Where they\u2019d all been studied in academia in isolation, Dr Diasinos brought them together, blending the used of CFD and wind tunnel testing at a time that it was the very leading edge of engineering development in F1.<\/p>\n
A motorsport fan, Dr Diasinos studied aeronautical engineering on the advice of Harvey Postlethwaite, who\u2019d worked for Hesketh, Tyrrell, Ferrari, and Honda. In a column for Racecar Engineering, he outlined the pathway into F1, a blue print Dr Diasinos followed to the letter.<\/p>\n
\u201cI was just a teenager watching Formula 1, dreaming one day of designing those cars,\u201d Dr Diasinos told PlanetF1.com. \u201cI never had the ambition of being a driver, I always just wanted to design. I used to read this magazine, Racecar Engineering. At the time, Harvey Postelthwaite was writing a two-page monthly column, and he outlined his ideal path for students now to enter Formula 1. It was to study aerospace engineering and the go off and do a PhD in some sort of vehicle dynamics or aerodynamics \u2013 that supposedly was going to make you attractive for Formula 1 teams. That\u2019s exactly the path I followed.\u201d<\/p>\n
Through high school, he tinkered with model cars and had been part of the World Solar Challenge programme, helping design a racecar of sorts while still a teenager. That continued into his time at university, before stepping back as he worked through his doctorate. Instead, he began to work in the local motorsport scene, gaining real world experience in the second tier of Australian Supercar competition and Formula series.<\/p>\n
\u201cI finished up leading the solar car team at the University of NSW,\u201d Dr Diasinos recounted. \u201cI got very close with the Dean of Engineering at the time, because he oversaw this project, and he helped me get a scholarship to do my PhD, but it was under the condition that I wouldn\u2019t continue working on the solar car project.<\/p>\n
\u201cBecause of that, I went out and started looking at local racing car teams that I could help. So while I was doing my PhD, I was doing Formula 4000 (ed- what had been Formula Holden and, before that, Formula Brabham). Back then, the second tier series for the V8 Supercars was called Konica Series, so I was doing race engineering for them, just volunteering, trying to learn more to get experience.\u201d<\/p>\n
The combination of people he met in the motorsport industry, the experience he gained, and his academic exploits landed him on the radar of Toyota\u2019s F1 team and, in 2007, Dr Diasinos found himself in Europe working with F1\u2019s newest \u2013 and one of its best funded \u2013 teams as a CFD engineer. Timing was perfect as, soon after, front wing rule changes were introduced that spoke directly to what Dr Diasinos had spent the last four years investigating \u2013 the relationship between a front wing in ground effect and a wheel directly behind it.<\/p>\n
\u201cMy PhD turned out to be really instrumental in my career,\u201d Dr Diasinos explained. \u201cIn academia, I had noticed a lot of people had studied just a wing in ground effect by itself; they had studied wheels by themselves. I always looked at open wheel cars and I looked at the front wing and the front wheel and thought those work so closely together, they\u2019re going to be interacting with each other. So that\u2019s what I investigated for my PhD.<\/p>\n
\u201cThe thing I investigated in my PhD was having no overlap to complete overlap and variations in between with different angles of attack and height for the wing as well.<\/p>\n
\u201cWhile I was working at Toyota, for the 2009 season, the FIA introduced a new rule set, and the new rule set was the first time that front wings were going to completely overlap the front wheels. It was fantastic for me, it was exactly what I\u2019d studied for the last four years.\u201d<\/p>\n
He duly found himself as part of the front wing design team, he developed a novel new concept for a front wing end plate. At a time when the double diffuser was the key performance differentiator, thanks to Dr Diasinos, Toyota headed into the new year with some interesting developments at the other end of the car.<\/p>\n
Imitation is the greatest form of flattery and, Toyota\u2019s design team was well aware that rivals would begin reverse engineering the design from the moment the end plate broke cover. While Dr Diasinos\u2019 design had worked well in the wind tunnel, and found its way onto the race car, it wasn\u2019t the only concept explored. Somewhat perversely, those failed avenues initially proved more valuable as the TF109 was unveiled to the world.<\/p>\n
![\"Dr](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/01\/sammy-diasinos-toyota-launch.jpg\")
<\/p>\n
Dr Sammy Diasinos (standing) with the Toyota TF109.<\/p>\n
At launch, Dr Diasinos\u2019 front wing end plate featured on the car, only not the real one; he\u2019d been tasked with creating a dummy design, one that drew on all the failed concepts, in a ploy designed both to hide the final solution as long as possible, but with any luck to send rivals down development rabbit holes (see image above). Three days later, the car made its track debut at the Algarve in Portugal, sporting an entirely different end plate solution.<\/p>\n
\u201cI designed the slotted front wing end plates that you first saw on the TF109,\u201d he said. \u201cThe really cool thing for me about that car was, we had a double diffuser, so everyone was hiding their diffusers because the diffuser was the big performance differentiator that year, but Toyota was the only team in pre-season testing that was also covering up their front wing, because they were trying to protect this end plate design that I initiated.<\/p>\n
\u201cThe other exciting part of that front wing design was that management recognised that it was going to be a unique design, so they actually asked me to design a fake front wing end plate for the launch car. So we designed this fake front wing end plate basically cobbling together all the ideas that didn\u2019t work together, made it look refined, and then 3D printed this massive fake end plate for the launch.<\/p>\n
\u201cI had former colleagues or friends in other F1 teams at the time looking at that fake front wing and saying \u2018Wow, Sammy you\u2019ve done a nice job on that end plate. It looks really good,\u201d only for a week later for the real thing to be released.<\/p>\n
\u201cThere\u2019s a lot of images of the TF109 that are circulating at the moment that have this fake front wing end plate on it.\u201d<\/p>\n
It highlights the lengths teams are prepared to go to in their attempts to deceive or cloud rivals with misinformation; a type of corporate espionage and competition intended to tie up resources and slow down development, and therefore prolong any advantage. Today, such subterfuge its easier with digital renders used instead of a real world car, with components often simplified or many generations old such that they\u2019re of no meaningful value.<\/p>\n
\u201cI feel really privileged that I got to work in Formula 1 before this limitation of wind tunnel testing and CFD testing came in,\u201d said Dr Diasinos. \u201cAT Toyota, we had two tunnels running 24\/7, in parrallel to each other. The office for the aerodynamics department literally was the bridge that was across those two wind tunnels.<\/p>\n
\u201cIt meant they needed people feeding ideas into these programmes to try; you can\u2019t keep a tunnel running 24\/7 if you don\u2019t have the ideas to test. They were very open to trying things which were a little bit out there sometimes. I\u2019ll never forget, when I first drew up that slot gap front wing end plate, my manager was like, \u2018that\u2019s not going to work\u2019. I was like \u2018Oh well, I\u2019ve submitted it to the cluster. Let\u2019s see what happens.\u2019 Lo and behold, it did work. So it was just being able to have the resources to be able to try things.\u201d<\/p>\n
By the following season, slot gaps were standard design features as teams look to control the airflow off the front wing, ahead of the front wheel\u2013 critical areas when it comes to efficiency and downforce downstream of the wing.<\/p>\n
At the end of the season, with three years of F1 experience to his name, Dr Diasinos moved to Williams, the team he\u2019s supported as a child, as a senior CFD engineer. It was a brief tenure, but one in which his experience linked the CFD and wind tunnel world had a real world impact on a team that, at that point, hadn\u2019t fully grasped the relationship.<\/p>\n
\u201cI had both CFD and wind tunnel experience, which at the time, those two tools were very segregated in how they were used and who was using them,\u201d Dr Diasinos explained. \u201cI don\u2019t think it\u2019s like that now, but back then, that was the case. Because of that, they saw me as a good person to try and connect what was being done in CFD with the wind tunnel programmes and trying to maximise the two together.\u201d<\/p>\n
The approach was different at Williams. There was less innovation or analysis going into development and the outcome of testing.<\/p>\n
\u201cIt was more about just feeding the cluster, feeding the wind tunnel, not really thinking about what it was that was being tested and why it might not be working,\u201d he said.<\/p>\n
\u201cI was able to show them a different way of how you would use the CFD tools, and then understand that certain components are not there to just add performance, but to help link different parts of the car together and optimise them as a package.<\/p>\n
\u201cThe under nose turning vanes is how I achieved that for the brief time I was at Williams. They had tested that concept before I arrived and not understood what they were supposed to do, and I was able to show it\u2019s actually a tuning device that helps you tune any front wing change that you make to work with your front floor. So I was able to demonstrate that through a series of CFD simulations and create a wind tunnel programme around that. After running that wind tunnel programme with them, those devices made it onto the car.\u201d<\/p>\n
Dr Diasinos\u2019 tenure at Wiliams was brief before he moved on to Caterham, one of the three squads that joined F1 in 2010. It was a vastly different experience to that of Toyota, but one where Dr Diasinos\u2019 influence could be made.<\/p>\n
It was there that he learned a lesson he\u2019ll never forget. A design choice, to lower the steering rack in the interests of improving the aerodynamics at the front of the Caterham CT01, contributed to a brake cooling issue that blighted the team for the next two season.<\/p>\n
\u201cThat will remain with me forever, because it was a mistake,\u201d he admits. \u201cIt was clearly a mistake that I made.<\/p>\n
\u201cWhen we were designing the CTO1 for Caterham, I was tasked with running a wind tunnel programme to determine what the front suspension layout should be from an aerodynamics point of view. One thing that I was very keen on testing was dropping the steering rack down towards the bottom of the monocoque, and having the steering rod go alongside the leading edge of the bottom control arm. In the wind tunnel, that was fantastic, it was a gain straight away. It looked really beneficial to have it, and so we went with it.<\/p>\n
\u201cBut the reason that this was a mistake was because we struggled with brake cooling that entire year. And the reason we struggled with brake cooling was because that steering rod was now connected to the upright in the most prime location for cooling the disc.<\/p>\n
\u201cThat was just something that my inexperience caused, so the whole year, we struggled with running oversized brake ducts, because we couldn\u2019t get the cooling that we needed. This lost more efficiency that we gained by moving that steering link down. It\u2019s something that I learned halfway through the season, and unfortunately, that monocoque carried into the next year as well. So that was a problem that the team carried for more than one year because of a decision I championed without understanding what the ramifications were for it.\u201d<\/p>\n
Today, Dr Diasinos is using the experience and lessons learned from working in F1 to teach the next generation and help them realise their engineering ambitions as a senior lecturer in mechanical engineering at Macquarie University. He\u2019s continued his early career academic work, contributing to a range of research papers broadly centred on aerodynamics and CFD. It\u2019s work that keeps him at the bleeding edge, just as he was almost two decades ago when he first headed to Europe. And through it all, his passion for F1 remains.<\/p>\n
Want to be the first to know exclusive information from the F1 paddock? Join our broadcast channel on WhatsApp<\/a> to get the scoop on the latest developments from our team of accredited journalists.<\/p>\n You can also subscribe to the PlanetF1 YouTube channel<\/a> for exclusive features, hear from our paddock journalists with stories from the heart of Formula 1 and much more!<\/p>\n