eRacing Magazine Vol 2. Issue 7 | Page 24

The ORECA O5 was new agenda for 2015, being a new look LMP2 car which shared the parts of the Rebellion LMP1-L R-one racer.

The ORECA O5 was long awaited by the press. A newly designed LMP2 which can contest in the 2017 series, after a huge revamp in the rules. The new car was

designed to be easy to use as well as faster than the highly successful ORECA O3 chassis run previously. The ORECA O5 is in fact a Rebellion R-One underneath (both cars sharing the same chassis and

bodywork), with very similar bulkheads too.

On the front of the KCMG run ORECA car, we can witness the tidy design of the break and clutch reservoir with the torsion bar suspension visible and the Aluminium anti roll bar.

When comparing the car to the Rebellion Le Mans aerodynamic package, you can see the twin front dive planes mounted below the headlight, as well as a small out board turning vane on the leading edge of the front splitter. Furthermore on the ORECA, the outer edge of the front splitter has a turning vane and only a single forward projecting dive plane. This would be a way to slim levels of coefficient drag and help shed the cars wake, as well as helping the car, under balance and load.

Looking at the back of the car, it was easy to note the unusual LMP2 design. The endplate is mounted inboard of the rear wheel centreline, with a vertical fin opposite it on the outer section. This would be for flow management. This design has been used on the Rebellion R-One too. The rear side of the engine cover features a lip which lines all the way on the trailing edge. This generates more downforce, as the airflow travels over it. The engine air inlet on the ORECA 05

Nissan is very conventional and essentially the same as that on the Rebellion R-One running the AER power plant.

The higher downforce specification on the ORECA 05 also has a number of different elements used by its customer teams. The front splitter remains identical, but there are now two large dive planes with a slightly flared lower part of the wheel pod. Also the twin louvres at the leading edge of the wheel arch hole (air extractor) are not present in Le Mans trim. This is because the team will direct that flow to

be used as downforce and not allow it to escape in the aid of straight line speed.

The Oreca 05 has been very fast out of the blocks. The design has really bonded well, and has seen multiple wins in the ELMS this year. The overall car is very sensible package and more importantly - fast. - as illustrated during their convinsing display at Le Mans despite losing chunks of time stranded at Arnage after the GT-R LM

NISMO leaked gearbox oil onto the track.

ORECA 05

Image: Octane Photographic

Image: Nick Holland