R25 chassis technical briefing

Renault technical director Bob Bell talks about the new R25

Q: The new R25 is an impressive machine. Can you tell us a little about it?

The new Renault R25.

Photo by LAT Photographic.

Bob Bell: The philosophy behind the car is very much one of evolution, and we hope the R25 will be a package capable of fighting for race wins. Last year, the mechanical architecture of the car was compromised by the late change of engine angle; the new RS25 engine has a lower centre of gravity, and a much stiffer installation than we were able to achieve in 2004. Our focus has been on optimising each detail to improve stiffness, reduce weight and package the components very tightly to give our aerodynamicists as much freedom as possible.

Q: What impact did the regulation changes have on the design process?

BB: We allocated wind tunnel resources as soon as the regulation changes were announced last July. That decision was a risk, and it cost us performance at the end of last season, but it was undoubtedly the right one. We have made a big step forward from our initial downforce loss of approximately 25%.

Q: What are the major innovations on the R25?

BB: We have an all-new electronic system integrating the engine and chassis controllers, named Step 11. It is physically lighter, representing a quarter of the total weight saving in the new car, and brings us a concrete advantage in terms of the scope of our development: we now possess four times' greater processing power, and ten times' more data acquisition capacity, all of which will contribute to improvements in our control systems. The other new feature of the car is the 'v keel' front suspension.

Q: Why did you choose this solution for the front suspension?

BB: In recent years, we have seen two schools of thought evolve in front suspension design: the traditional single keel, with a single front lower wishbone, and the twin keel, which brings a measurable aerodynamic gain but can also have a structural penalty outweighing the benefit. We believe the v-keel is a very elegant solution to this dilemma, as it combines the virtues of both systems: we have obtained an aerodynamic advantage for minimal structural penalty, while maintaining our preferred mechanical configuration for the front suspension.

Q: Overall, what are your expectations for the car?

BB: The R25 is certainly the best-integrated car the team has produced so far. We have worked very closely with Viry to optimise the engine installation, and the aerodynamic improvements from our initial starting point are beyond what we would normally expect under stable regulations. I am confident that the numerous gains we have made will translate into a concrete step forward in competitiveness on track.

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