Carlin's F2 chief engineer has had a chequered route to his current role, from Formula Ford champion to sim entrepreneur to doctorate to the BMW-racing brains of the boys in blue
He's the studious-looking, unflappable, softly spoken guy behind much of single-seater powerhouse Carlin's success. Few would believe that behind this placid facade is a man who, at the start of any given season, has more race wins to his credit than most of the squad's current drivers.
The job for Dutchman Stefan de Groot - 2001 Dutch Formula Ford champion in another life; Carlin Formula 2 chief engineer in this one - is to get those drivers' win tallies above and beyond his own.
For a decade, de Groot's motorsport career carried him from one thing to another in rapid succession, including his start as a professional engineer triggered by the need to repay debts incurred from his own racing career.
For the past decade, he's had the stability of being one of the 'boys in blue' at Carlin, an oasis of calm, and instrumental in the career of the team's most-celebrated 2010s talent: Lando Norris. And in between all that, he earned a doctorate...
It all started for de Groot when "I got onto racetracks from a really young age. My father was a mechanic for amongst others my uncle with historic cars - always with MGs and Austin-Healeys."
Without any karting background, de Groot went racing in Formula Ford. In 2000 he won the Dutch and Benelux 'Class B' titles for those in older machinery as a privateer; the following year he became overall Dutch champion with the Geva Racing Mygale squad.
"I only started when I was 18 with driving - much older than what you do nowadays," he relates.
"I did everything at first with my dad and then with fellow students, which was quite cool. It was an enjoyable time looking back at it. The students from that team all went to a bigger team [Geva] the year after with me, to work on the Formula Ford, so we were all hired basically."
De Groot and his pals were all at university: "My goal was to become a Formula 1 engineer, and that's why I went to do aerospace engineering. We were all going that route, that's where we all knew each other from."
At that time, de Groot's parallel path in trying to make it as a driver, in FFord and then Formula 3, was interrupting his studies.
"Because I had some financial troubles trying to continue [driving] when I shouldn't have, I had to start working with Geva as an engineer" Stefan de Groot
"I was taking it really seriously," he says. "The longest period I wasn't in university was almost a year - one time I went there and I didn't even know how to log in anymore!"
The FFord career finished with a starring role in the Festival at Brands Hatch, as part of the annual Dutch invasion of the end-of-season classic. He'd been 10th on his maiden visit in 2000; one year on, de Groot (pictured below) won his heat.
"That was the fastest heat, and I was on pole for the semi-final," he recalls. "Then on the Sunday it rained, and I hadn't driven enough there in the wet, so that was it.
"I lost a place at the start, and then I lost another place to Alan van der Merwe [the eventual winner], and in the final I started fifth and nothing happened - we just finished where we started."
De Groot made the logical step to the German Formula 3 Championship for 2002, finding a berth at Belgian team JB Motorsport, but it didn't go well: "I had a manager who was financing it, and during the year we had more and more issues and I sort of fell out with him."
The split came after August's Marlboro Masters on his home track of Zandvoort. De Groot had qualified an impressive seventh out of the 45-car field on a weekend where JB collaborated with British F3 minnow Menu Motorsport. Menu had just split with one of its drivers, Colombian Giandomenico Brusatin, and the following weekend de Groot was at Oulton Park to complete the season in the UK.
As team-mate to Rob Austin, he scored six points finishes in eight races, including a podium at Thruxton (pictured below, ahead of that year's champion Robbie Kerr).
"Mick Kouros [Menu engineer] and Mike Baker [team boss] liked me and they helped me to get going in the UK," explains de Groot. "I was sort of there or thereabouts a couple of times immediately, which was really cool, because before in Germany it wasn't going well at all."
A one-off with Alan Docking Racing netted a strong sixth place in the end-of-season Korean Super Prix, but de Groot's career was running out of financial steam: "For the year after I tried to set up an investment scheme, but it didn't work out.
"I did a couple of Formula Renault races with Geva but it was not good [although there were podium finishes]. Then because I had some financial troubles trying to continue when I shouldn't have, I had to start working with Geva as an engineer. And in the meantime I was refocusing on university to try and finish that."
Thanks to connections at Zandvoort, he was introduced to the Strous family - Ton Strous was running a team in Dutch FRenault for his son Junior, and de Groot was hired to engineer at the quirkily named Mr Glow Motorsport. Strous won the Dutch title in 2004, plus the FRenault Winter Series in the US, but the step up to Eurocup for the small operation proved a touch ambitious - Strous went to the rapidly expanding German team Motopark, and took de Groot with him.
While Strous graduated to the US scene, and would win races in the Atlantic and Indy Lights series, de Groot remained at the Oschersleben squad: "Back then we did multiple cars per engineer [in FRenault]. I worked for two years with Tobias Hegewald, but in those years we had drivers like [Red Bull juniors] Filipe Albuquerque, Scott Speed, John Edwards... I worked with Brendon Hartley.
"Then I stopped. There was a bit of friction, let's put it like this, between me and another engineer, and in the end we couldn't really gel on quite simple physical things, and I knew I was correct - the problem is he would say the same thing!"
De Groot had remained friends with Ludo Loots, his engineer in his JB Motorsport F3 days and now working on the Van Merksteijn Motorsport Porsche RS Spyder, with which owner-driver Peter van Merksteijn was tackling the European Le Mans Series and Le Mans 24 Hours in 2008. Loots called up de Groot, who suddenly found himself working as data and performance engineer for Jeroen Bleekemolen and Dutch racing superstar Jos Verstappen.
The team came just 26 seconds (the margin by which Verstappen and van Merksteijn were beaten at Monza) short of winning all five ELMS races in the LMP2 class, and claimed victory in the division at Le Mans (pictured below). It was an eye-opener, and crucial to de Groot's education into how a racing team should be.
"We went all-in from the start, no costs were spared to get the best of everything. Unfortunately it went so well that the objectives were reached in one year and so the team ended" Stefan de Groot on the Van Merksteijn Porsche project
"Ludo and I knew we worked well together," he says. "Apart from running the systems on the car my main task was to coach Peter to drive the car, as he was our gentleman driver. During the races I did the fuel calculations.
"The car was extremely good, we had a lot of support from the Porsche factory and all the team members were good at their job. The team philosophy was also really good in that we went all-in from the start, no costs were spared to get the best of everything. Unfortunately it went so well that the objectives were reached in one year and so the team ended."
De Groot washed up in 2009 in the Formula Renault 3.5 series with the Interwetten squad, which, by contrast, "was a really ill-funded team". But paradoxically, this was crucial for his future. While de Groot engineered a revolving cast of drivers (including Hegewald), former Brabham Formula 1 man and long-time Carlin collaborator Harvey Spencer was on the sister car of Adrian Zaugg.
"Harvey is the link with Trevor Carlin," explains de Groot. "Harvey told Trevor, 'Hire that guy'! Since then I've been with Trev."
Carlin needed an extra engineer as it expanded its British F3 line-up to six cars, so de Groot was brought in to look after Lucas Foresti in 2010, then ran Rupert Svendsen-Cook in 2011 and Harry Tincknell in 2012. As the F3 European Championship absorbed the British series, de Groot worked with Tincknell again in 2013, scoring a win at Silverstone, before he took on Ed Jones in 2014.
Behind the scenes at Carlin, a plan was hatching to set up a team in a new category around a 14-year-old kid from a wealthy family who'd been winning Ginetta Junior races...
Cue a new role for 2015 within Carlin for de Groot: the guy who oversees new projects.
"I think maybe Trevor was already planning for me to do that but I'm not entirely sure," he says. "But anyway, I was asked to do that job, to engineer Lando Norris and to set up the new British F4 team within Carlin.
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"That was my first year as a lead engineer, but interestingly it was with Harvey and Matt Ogle [who had run Jack Harvey to the 2012 British F3 title at Carlin and was simultaneously working with Antonio Giovinazzi in European F3]. So for an F4 team we had a pretty decent crew! A massively experienced team for junior motorsport."
Norris (pictured below at Croft) won the title, with team-mate Colton Herta third, and they played a cameo part in de Groot's next project - Carlin's team in the new-for-2016 BRDC British F3 Championship.
"I was asked to set that one up, just like the F4, and Colton was going to do a couple of races [between his Euroformula Open commitments] and Lando [whose main focus was FRenault] was going to do a couple in that car. Matt Ogle also joined in and he was running Ricky Collard.
"It's cool to start it up with experienced people. You sort of hit the ground running. In any new championship you have a lot of start-up issues with the cars, and it's just good to be quick with finding solutions. It's very interesting. Then after some hard negotiations, we managed to get Lando for European F3, and that was my first year being fully off the car - I was chief engineer of the team [Ogle was Norris's race engineer]."
For 2017, substantial aerodynamic and safety modifications had been made to the Euro F3 cars, meaning a bigger focus on winter development. Furthermore, series rookie Norris was up against proven F3 star turns Maxi Gunther and Callum Ilott (both with the all-conquering Prema) and Joel Eriksson (Motopark). Even so, Norris won the title, fulfilling a dream for Carlin - so often the dominator in the old days of British F3, but never top of the pile in Europe - and de Groot himself.
"It was a lot of work, and it was a life goal of mine," he sighs. "It was very important. I would have given up a lot for that - and I did - but yeah, that was something that just had to be done."
"The research part of my doctorate has helped me quite a bit, it's still helping me, just the whole idea of how to do an experiment, and do some proper statistics" Stefan de Groot
Norris came close to a deal with Prema for the step up to Formula 2, which would be using all-new cars for 2018, only for that to be vetoed by team part-owner Lawrence Stroll. He then turned to Carlin, which returned to a category it had abandoned at the end of 2016, with de Groot installed as chief engineer.
"A new championship, and the same thing again... a new team all the time," he says.
Although neither won the drivers' title, Norris and Sergio Sette Camara combined to give Carlin the teams' crown - a remarkable achievement in its F2/GP2 comeback season. As in F3, part of Norris's downfall was his prowess when the lights went out.
"Mainly starts and all the troubles you get from that were hurting us," explains de Groot. "If you drop back a couple of positions then it costs a lot of tyres to get back.
"With Lando being a rookie, you do need to learn how to deal with that, how to save tyres. And also for me it was a complete learning experience to see how that all works and has to be played. Lando is super-quick, but he also had to learn a little bit; we kept learning throughout the whole year."
De Groot has stayed in the F2 chief engineer role since then, with Nobuharu Matsushita and Louis Deletraz representing the team in 2019, and Jehan Daruvala (Norris's F3 team-mate from 2017) and Yuki Tsunoda on board for when the 2020 campaign finally begins.
Has there been much development on the cars in the two years since they were introduced?
"Quite a lot, and now we have the 18-inch wheels of course, so it's exciting," he says. "They've improved the whole clutch system [which caused so many problems in 2018], and we're sort of comfortable with the car. It all feels much more under control than it did then!"
Shortly into his Carlin career, de Groot also established a simulator company in the Dutch city of Delft with 1999 Dutch FFord champion Vincent van der Valk, whose face is familiar in the Formula 4 paddocks of Europe as engineer and coach with Van Amersfoort Racing. The entirely logically named SimDelft is all tied in to de Groot's PhD, for which he researched new concepts for simulator driving on road and track.
"The research part of it has helped me quite a bit, it's still helping me, just the whole idea of how to do an experiment, and do some proper statistics," enthuses Dr. de Groot. "But for the rest it ['Doctor'] is just a nickname - I'm not doing anything in university or scientifically anymore. It was simulated driving, and I sort of took racing with it, because you can do good experiments with racing drivers.
"We [SimDelft] were one of the first to use it to train drivers I think, and we've always stayed relatively low key. Some racing drivers knew how to find us, but it never grew very large. Vincent is still continuing with it now. I'm still involved but I'm not really doing training sessions with drivers anymore, although I do help with simulator development a little bit."
De Groot's expertise is also useful for the simulator at Carlin. That includes a layout that the team refers to as 'Double Tarzan' - basically a short track using the fiendishly tricky, mildly banked first corner at Zandvoort.
"It's a difficult corner, and it's twice in a row, so it's like an American oval with proper braking!" laughs de Groot.
Double Tarzan is a good track for newcomers, but, says de Groot, "you'd be surprised how fanatical even experienced drivers are when they hear that somebody else has gone quicker on it. The beauty of it is that it's quite easy to get to the limit, and you have to do all the right things to be fast, and you can easily talk about it, explain it."
"Don't switch too quickly from one job to the other because it's all about the people you have around you. The more you know the people around you, the more effectively you can work with everybody, and then it becomes more enjoyable" Stefan de Groot
De Groot's own exploits in the Carlin sim leave him "half a second to a second off every time - it drives me crazy!" But he still dabbles in real-life racing. Occasionally he gets behind the wheel in the Netherlands in his BMW E30 Cup car.
Meanwhile, lurking in the garage is a Mondiale M89S FFord that, years ago, he told this author he wanted to take to Silverstone for a crack at the Walter Hayes Trophy: "That's still a plan - I need to get a move on but I'm getting more and more busy; it's not ideal."
If he did that, chances are he might be battling a future Carlin driver, one who he could one day play a part in moulding into a star of the future.
Top tips for engineers from Stefan de Groot
What I value the most is the people around me, and the good discussions you have with them to get the maximum amount of information and new ideas. If you combine a couple of brains, you get much more than what everyone already knows. For any difficult problem, that's really important, to be open-minded.
I am always excited to find new problems. I still feel like I'm fully learning and developing, and keeping an open mind to everything, with an outlook of curiosity.
What I really like about my work for Trevor is I know the team, I know the people who are in it, and that gives me a very good base to get stuff done very efficiently. Don't switch too quickly from one job to the other because it's all about the people you have around you. The more you know the people around you, the more effectively you can work with everybody, and then it becomes more enjoyable.