The technical specifications of the Renault F1 RS25 V10 engine for the 2005 World Championship.
The RS25 has been designed specifically to meet the new two race weekend reliability regulations imposed by the FIA.
• 72° 'V' angle with optimum integration in the new R25 chassis.
• Atmospheric 3-litre V10 engine.
• Mass optimised for the required reliability, with a gain relative to the RS24.
• Reliability of more than 1400km with a performance gain relative to the RS24.
• 98 % of parts are new.
Engine Technical Director Rob White discusses the new RS25 V10 engine, and meeting the challenge of two weekend reliability.
You have said the RS25 is an evolutionary step: what is the crossover from last year’s engine?
The RS25 is a clean sheet design, and shares no major components with RS24: 98% of the parts are new. The engine maintains the 72° 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.
The engine will be running a brand new electronic system: what benefits does this bring?
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.
What has been the impact of the technical regulations on performance development?
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.
What was the impact of the regulation changes on the engine’s development?
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.
Finally, will the new regulations bring about cost savings?
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.
The technical specifications of the new Renault F1 R25, 2005 race car.
Renault F1 R25
Chassis
Moulded carbon fibre and aluminium honeycomb composite monocoque, manufactured by the Renault F1 Team and designed for maximum strength and stiffness with minimum weight. Engine installed as a fully-stressed member.
Front suspension
Carbon fibre top and bottom wishbones operate an inboard titanium rocker via a pushrod system. This is connected to a torsion bar and damper units which are mounted at the front of the monocoque.
Rear suspension
Carbon fibre top and bottom wishbones operating vertically-mounted torsion bars and horizontally-mounted damper units mounted on the top of the gearbox casing. Bottom wishbone attached by ‘v’ keel mounting.
Transmission
Six-speed semi-automatic gearbox with one reverse gear.
Fuel system
Kevlar-reinforced rubber fuel cell provides reduced risk of fire and is mounted behind cockpit in chassis monocoque.
Cooling system
Separate oil and water radiators located in the car's sidepods and cooled using airflow from the car's forward motion.
Electrical
Integrated chassis/engine electronics and software co-developed by Renault F1 Team and Magneti Marelli.
Braking system
Carbon discs and pads (Hitco); calipers by AP Racing.
Cockpit
Removable driver’s seat made of anatomically formed carbon composite, with six-point harness seat belt. Steering wheel integrates gear change and clutch paddles.
Car dimensions and weight
Front track 1,450mm
Rear track 1,400mm
Wheel base 3,100mm
Overall length 4,800mm
Overall height 950mm
Overall width 1,800mm
Overall weight 605kg including driver, camera and ballast
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