RS25 engine technical briefing

Renault engine technical director Rob White talks about the new RS25

Q: You have said the RS25 is an evolutionary step: what is the crossover from last year's engine?

Rob White: The RS25 is a clean sheet design, and shares no major components with RS24: 98% of the parts are new. The engine maintains the 720 architecture of its predecessor, but we have included the lessons learned from RS24, and further refined the engine-chassis integration. The engine's centre of gravity is significantly lower, recovering nearly 70% of the difference relative to the previous generation of wide-angle engines. Equally, despite the doubling of life for this season, the engine has not gained in weight.

Q: The engine will be running a brand new electronic system: what benefits does this bring?

RW: We will use the Step 11 system in 2005, a combined chassis and engine controller developed with Magneti Marelli. This major programme has run in parallel with the car and engine design, and marks a further step in the integration of the two. Conceptually, the target has been to simplify the electrical and electronic installations while providing a more powerful platform for the development of engine and chassis control systems.

Q: What has been the impact of the technical regulations on performance development?

RW: We are pleased with the performance of RS25 at this stage of its development. The engine must drive cleanly through a huge rev range in modern F1, and we will therefore develop the engine's torque curve and power delivery according to the same philosophy of total vehicle performance as its predecessors. In terms of specifics, the RS25 has hit or exceeded all of its performance objectives thus far .

Q: What was the impact of the regulation changes on the engine's development?

RW: The changes arrived too late to affect the overall philosophy of the engine but in order to respond to them, we had to review every component and system, and conduct detailed risk analysis on the impact of extending engine life. Parts must now last four times longer than two years ago, and to ensure we can meet the challenge of the regulations, we must respect extremely strict quality requirements.

Q: Finally, will the new regulations bring about cost savings?

RW: The direct engine costs of running the car will be lower in 2005: the number of engines built will be substantially less and although each one is more expensive, there is a net saving. Change obviously has cost implications in terms of development, and these costs will offset the savings for the manufacturers. However, it is reasonable to expect that small teams buying engines will see real economies thanks to the regulations.

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