An engineer’s guide to Rally1

DirtFish enlisted the help of Hyundai's Julien Moncet to talk through the tech on the hybrid-equipped cars


There’s been plenty of attention on the World Rally Championship’s hybrid-equipped Rally1 cars this week, but how is the extra power actually deployed?

Step forward Julien Moncet – Hyundai’s powertrain manager – who was on hand during the team’s rally simulation test earlier this week to give DirtFish the lowdown.

DirtFish: You are the man who’s responsible for the engines and the hybrid unit. In simple terms, how does it work?

Julien Moncet: Ha! It’s not easy because as you say we have to combine the combustion engine and the electric power from the e-kit. Both have to work together so basically how does it work? We use the engine mostly still, the internal combustion engine, and the e-kit supports the combustion engine when we need more power.


DF: How much more power can you get, and how often can you use that power?

JM: The e-kit is able to provide 100KW, so about 134bhp, and we have a limit of energy that we can use. It depends on the stage lengths and the surface as well.

DF: How is the energy deployed? Does the driver have a button, is it something to do with the throttle?

JM: The driver has three maps, actually three plus three. Three maps for boost, and three maps for generation to select before the stage. Once he is in the stage he cannot change them anymore. He can disable the kit if needed, he can re-enable it after but he has a large time of 60 seconds. It’s kind of an automatic system, it works on throttle and brake pedals.

DF: You mentioned regeneration, what do you mean by that? What is regeneration?

JM: So before having a boost with the e-kit we need what we call a valid regeneration. To get it, it’s given by pressure off-throttle a little bit and you need to reach a level of energy recovery.

DF: Energy recovery comes from braking?

JM: Yes. And if you don’t switch the energy level then you are not qualified for the boost.

DF: So if you’ve used 100% of the available power in the battery, how much braking do you need to regenerate that battery?

JM: It’s not easy to answer this one.


DF: Put it another way. If you’ve used the boost and it might be what 10 seconds, 15 seconds of boost, how long would you have to wait until you could use it again?

JM: It really depends on the stage actually. You get the power back on braking and on reacceleration, it depends on the surface and the acceleration. If you don’t have time and energy back then you have no boost, then you have to wait for the next corner.

DF: What if you’ve used all of your extra boost by the end of a stage. How easy is it to regenerate it before the start of the next stage?

JM: Then you’ll have to regenerate on the road section. You still have to use the combustion engine to recharge some of the battery, you still need it.

DF: It sounds quite complicated

JM: It’s not. With the FIA and the other manufacturers we have tried to keep the strategy as simple as possible, also to avoid using too many resources and so on. It will require some adaptation, mostly for the drivers and also on the engineering side, but it’s not complicated, no.

Words:DirtFish Media

Photography:Corrado Manera