BMW Sauber F1 Team
2007 FIA Formula One World Championship

The BMW P86/7 engine

V8 reloaded.
Following the fundamental conceptual shift from V10 to V8 engines ahead of the 2006 season, the focus is now on the development of clever details for the Formula One powerplants of the future. In 2006 the decision was taken to freeze large areas of engine development until after the 2010 season.

The homologation of the 2.4-litre V8 units requires technical monitoring and has been conducted in several stages. The Formula One teams’ engines started to appear at the FIA office in Chessington, England towards the end of the 2006 season. All the manufac¬turers were required to submit an engine which had come through two GP weekends.

To be on the safe side, BMW decided to put aside the first P86 engine as early as Monza, with further development work continuing apace at the same time. Having met its obligations, the team had earned itself extra room for manoeuvre when it came to making improvements. The engines in Nick Heidfeld and Robert Kubica’s cars completed the final races of the season in Japan and Brazil without a problem, and Kubica’s unit was handed over to the FIA. The deadline for engines was 22nd October, but that didn’t mean the engineers could go into hibernation for the winter.

The teams were able to submit a list to the FIA – by 15th December 2006 at the latest – containing modifications to the engine (except the pre-specified core) which they were intending to carry out by 1st March 2007 in order to adapt it to the rev limit of 19,000 rpm. In simple terms, while the block and crankshaft had to remain untouched, further tweaks were allowed to the cylinder head and peripheral components. Additional enhancements were permitted to details of the intake and exhaust piping, lubricant and fuel supply, pistons, valves and mounts. Alterations required to install the engines in the new cars were also given the green light.  

A new central control unit for the engine, transmission and chassis replaces the previous engine electronics. The new development has been christened RCC, standing for Race Car Controller. The designation of the BMW power unit reflects the fact that the engine concept must remain unchanged: it will be known as the BMW P86/7, rather than the P87.

Fixed parameters for all.
The introduction of the V8 engines in time for the 2006 season was underpinned by a series of central parameters governing their construction. Displacement of 2,400 cc and a bank angle of 90 degrees were stipulated for the V8 engines. The powerplants had to tip the scales at no less than 95 kilograms. This included the intake system up to and including the air filter, fuel rail and injectors, ignition coils, sensors and wiring, alternator, coolant pumps and oil pumps. It did not include liquids, exhaust manifolds, heat protection shields, oil tanks, accumulators, heat exchangers and the hydraulic pump. 

The new regulations stipulate that the engine’s centre of gravity must be at least 165 millimetres above the lower edge of the oil sump. The longitudinal and lateral position of the V8’s centre of gravity has to be in the geometric centre of the engine (+/– 50 millimetres).

The cylinder bore is limited to a maximum 98 millimetres. The gap between the cylinders is also set out in the rulebook – at 106.5 millimetres (+/– 0.2 mm). The central axis of the crankshaft must not lie any less than 58 millimetres above the reference plane.

Variable intake systems designed to optimise torque have also been banned since 2006. The power supply to the engine electrics and electronics is limited to a maximum 17 volts and the fuel pump has to be mechanically operated. Only an actuator may be used to activate the throttle valve system. With the exception of the electric auxiliary pumps in the petrol tank, all subcomponents must now be driven mechanically and directly via the engine.

In addition, a long list of exotic materials have been excluded and the team limits itself to working with the conventional titanium and aluminium alloys stipulated in the regulations. Another restriction which will come into force for 2007 and the following years is a cap placed on engine speed at 19,000 rpm

V8 development from November 2004 to February 2007.
Development work on the BMW V8 engine began in late November 2004. The champagne was flowing at BMW’s Formula One engine factory in Munich in May 2005 after the first-specification V8 successfully completed its opening examination on the test rig. An updated specification made its track debut in Jerez on 13th July 2005. A further developed version was then introduced in time for winter testing, which began in Barcelona on 28th November 2005. The next stage of development was ready for the first rollout of the new car on 17th January 2006, and this was followed by another update for the first race of the season and a series of new specifications as the year went on. The later versions were developed with one eye on the homologation process to come.

As Theissen explains: “A Formula One engine is never the finished article. It’s like a painting that may already look finished to the onlooker but which the artist, knowing precisely where he can improve his work, will still touch up here and there. A single stroke of the brush can change the whole effect. Far from reducing development work to a standstill, the increased number of regulations has merely shifted the emphasis. It’s important that Formula One remains at the cutting edge of technology, and that’s what it will do.” 

Power for longer.
The mileage a Formula One engine is required to cover has changed dramatically in the recent past. 2002 was the last season where a new engine could be fitted ahead of every race. Back then, qualifying saw the use of highly tuned engines which the teams would never have dared risk over a full race distance.

In 2003 the rules changed to force the teams to use the same engine for qualifying and the race itself, and that was followed by the introduction of the whole-weekend stipulation in 2004, doubling the mileage the engine had to cover. Since 2005 the engines – then still 3-litre V10 units – have had to hold it together for two full GP weekends. An unwanted side effect of this rule saw the GP drivers preserving their engines during Friday practice and staying in the garage as much as possible. In order to offer the fans more in the way of action, the Friday sessions have now been granted exemption from the engine regulations for the 2007 season. This will encourage the drivers to spend more time out on the track during what are now two 90-minute sessions.

Only from Saturday will the teams be obliged to fit the engines in their cars which must then last two GPs – under the watchful eye of the FIA.

Longer at full throttle.
The lower output of the V8 compared to the V10 engines means the cars spend longer under full throttle. BMW’s figures show that the average proportion of the race spent at full throttle in 2005 was 56.67 percent, with that figure rising to 63.53 percent in 2006.

Practice behind closed doors.
Before a new specification reaches race readiness, it has to successfully complete an extended session on the dynamic test rigs. BMW first introduced the new-generation testing facilities, which stretch out over several floors and fill entire halls, in autumn 2005. The exacting challenge for the powerplant remains unchanged: 1,500 kilometres on a pre-programmed circuit profile based on Monza. No other GP venue can match the full-throttle percentage of the Italian track. Engines earmarked for transportation to the race venue complete a rather more gentle functioning check on the test rigs. This is followed by quality checks, with the oil undergoing spectrometer analysis to identify any metallic residue. Then it’s time for action on the track.   

Shifting faster.
One section of the new testing facility at Anton-Ditt-Bogen is used by the transmission development and testing department now based in Munich.

A Formula One race transmission needs to display maximum rigidity, yet at the same time be lightweight, have a low centre of gravity, be compact and boast extremely short shift times. The BMW Sauber F1.07 is fitted with a 7-speed gearbox. The main and auxiliary drive shafts are arranged longitudinally to the direction of travel. The driver can shift up a gear without breaking off tractive power to the rear axle. In a conventional Formula One transmission, engaging the clutch results in the flow of tractive power being interrupted for approximately 50 milliseconds during the shift process. In other words, during this time the car is deprived of propulsion and just rolls – in particular at high speeds against high wind resistance. In practical terms, the car is braked by around 1g during this suspension of tractive power. In a road car, this would come across as powerful braking.

This interruption of tractive power every time the driver shifts up a gear – which he will do some 2,000 times over the race distance of the Monaco Grand Prix – adds up to a significant loss of time or a deficit of several hundred metres by the end of the race. The new quick shift gearbox (QSG) fitted in the BMW Sauber F1.07, however, totally eliminates this break in tractive power. The ingenious interplay of electronic and mechanical components is the key.

Both the development and production of the QSG takes place in Munich. The transmission’s extremely durable toothed gears – partly manufactured at BMW’s Dingolfing plant – are made of high-strength steel, while the transmission housing consists of cast titanium.

Converting torque and engine revs is just one of the transmission’s jobs. It also has to pass on the forces generated in the suspension to the chassis via the engine.

The BMW P86/7 Technical Data

More:
The BMW Sauber F1.07 Chassis
The 2007 FIA Formula One World Championship - Changes
Driver Profile - Nick Heidfeld  
Driver Profile - Robert Kubica