Renault Group

The origins of E-TECH technology

episode 1

LEGO plus a touch of boldness

Using its expertise in electric vehicles, its experience in Formula 1 and with the enthusiasm and passion of its engineering, development and control teams, Renault has developed the innovative hybrid E-TECH powertrain. Offered in a “full hybrid” version on the Clio and in a “full rechargeable hybrid” version on the New Captur and New Mégane, this was invented and developed in a way that was both unusual and truly inspiring. Read the first instalment of this astonishing story to find out how it all began… with a LEGO model.
The LEGO model inside a Clio E-TECH Hybrid

#1 A studious Christmas

It is December 2010. Christmas is coming and Nicolas Fremau orders lots of boxes of LEGO online. Are these presents for his children? Not exactly… Right now, he is the Gearbox Architecture Expert in Renault’s Engineering Department and he has an idea at the back of his mind: to take advantage of the holidays to use the multicoloured plastic bricks to design a small-scale prototype of an innovative transmission specifically designed for a future hybrid powertrain.
Initial schematic diagram

At the time, Renault’s involvement with electric vehicles is beginning, but the Group is determined, at the same time, to develop an alternative electrification technology that will provide lots of customers with a smooth transition towards all-electric. Several technical solutions are envisaged but senior management has to be presented with THE ideal hybrid solution that will meet all of their requirements. It will have to be accessible, light and suited to vehicles of every size, with a minimum all-electric range of 50 kilometres. In other words, it has to provide effective hybridisation for all.

Renault Type A with dog gearbox

Nicolas has no doubts: it will mean treating the electric traction engine as the main driving force and as the component that will be used to start the vehicle. The combustion engine will then kick in as a support to drive the wheels over long periods. And what about transmission between the two components? The obligation is to create something simple, compact and light. As an expert in the field, Nicolas is able to come up with a radical solution. Let’s do without a clutch and even gearbox synchronisers. There is a technology that will allow this, the dog clutch, which is used, in particular in motor sport. It is also a Renault “speciality”, as it was by installing a dog clutch gearbox with a direct connection to the engine on his Type A in 1898 that Louis Renault managed to climb the steep rue Lepic to Montmartre, thus launching the brand’s commercial adventure.

« Eurêka » exclaims Nicolas, but he still has to make a successful model of this transmission which, for now, exists only in his head.

#2 Assemble it, drill it, glue it

So, here is the aim for his holidays: to create this much-vaunted, simplified clutchless transmission system using LEGO. It will have three gears to manage the various modes in which the engines will inter-operate. To achieve this, it takes more than just sticking the bricks together. He has to assemble the various transmission shafts and rings, glue and drill them to hold them in a subframe, drive the assembly, etc. A true engineering task that paves the way for the work that will be carried out subsequently in the Technocentre and Lardy workshops, work that will result in the submission of over 150 patents related to the E-TECH hybrid powertrain.
The start of an innovation project is always a tricky time! What do you do to reassure yourself that an idea really will work? There are no ready-made recipes. First of all, and at every step, you have to know if there is a bug or if it has any chance of working! However, and above all, you have to find a way to go beyond mere drawings on the back of an envelope. So to make this system a reality, I had the idea of this little LEGO model, first of all to help me understand what had to be done. After about twenty hours of work, with a few disbelieving glances from my son, the model came into being.
Nicolas Fremau 
Powertrain and Hybrid Expert

#3 If we can make it out of LEGO…

With his powered model made from LEGO, Nicolas can now run live tests on the various ways that the engines can operate together. Better still, he finds new ways that hadn’t occurred to him when he carried out his preliminary theoretical analysis. This only strengthens his belief that he is on the right track. However, to be sure, he needed the views of other people.
View of the LEGO model

Therefore, Nicolas approaches several of his colleagues: Ahmed Ketfi-Cherif, the control specialist, to confirm that the transitions between the various modes are possible with simple dog clutches; Antoine Vignon, the gearbox design specialist, to confirm that it is possible to make the new system on an industrial scale; Sid Ali Randi, the electric engine specialist, to confirm that he is able to adapt an engine to this transmission. Faced with this surprising request, each of these “big beasts” needs several days to ponder the issues. They have to study the diagrams, analyse the model, listen to Nicolas’ explanations. However, in the end, all three concur. « Yes, it can be done ! ».

Electric motors and transmission of the E-TECH motorization

With his LEGO model and his operating principle now validated, there is no doubt that Nicolas has developed the cheapest prototype ever in Renault’s history. A prototype named LocoDiscoBox that is as surprising and unexpected as the technical solution is innovative. But how would the managers to whom this model was to be presented react? We refer here to Rémi Bastien and Gérard Detourbet (who died in 2019), the «daddy» of the Dacia range, who knew all about simplified, low-cost solutions? At the time he is the Director of the M0 ("Entry" program) range, and is forever saying in meetings, « Stop adding components and costs, think about removing, replacing or simplifying instead! ». Even so, it’s a real gamble for Nicolas.

The day I took the model to Remi Bastien and Gérard Detourbet, I had no idea what they would say. However, Renault has always been a really open company, so I chanced my arm at the end of a project meeting. And what do you know? They liked it! Gérard Detourbet even said this:

« If you can make it out of LEGO, it has to work! »

However, this green light came at a price. They wanted a commitment to get the concept operational in a car that actually ran in a mere 14 months!

Nicolas Fremau 

Powertrain and Hybrid Expert

Detailed view of the LEGO model

After this unexpected go-ahead, the first step was to contact Renault’s legal department for quick action to obtain protection for this brand-new transmission with an initial patent. This was done in double-quick time. What a relief! Yet, for Nicolas Fremau, Antoine Vignon, Ahmed Ketfi-Cherif, Sid Ali Randi and a small team of passionate colleagues at Renault Engineering, the hard work on the project, that would to lead to hybrid vehicles, was only just beginning.