Ever since pictures were released of the GTR NISMO, a different but fascinating approach had been taken by the team, which is completely different to your normal LMP1-L cars. At the heart of this prototype is the Cosworth bespoke three litre V6 engine, which is pure engineering at its best. Since the cars lunch more pictures have been taken of its power unit. Here are the updates and analysis of this under the radar racer.
Details of the VRX30A block are still well hidden by the team. By looking at the block it looks like the bank angle is narrower than the 90° angle used on the F1 block. However it is likely that lessons and technologies used on the F1 engine have carried over into the VRX30A unit for it to perform well enough against the top LMP1-H cars.
Nissan claim that the V6 engine carries over much philosophy of the GT-R GT500 car engine, a turbocharged direct injection fourcylinderr design. Another view (above) shows the level of complexity of the systems around the V6 engine. The design of the GT-R LM’s front end forces this very tight packaging. Which has been used for 60% front end downforce, the key whole for this P1 car.
One of its largest problems with the GT-R LM is the incredibly tight front end packaging. Cooling for the V6 comes from front mounted radiators with a inlet duct ahead of them, but two turbochargers, the front suspension, brakes, and transmission all have to be packaged into this very small area. The transmission is almost not existent it’s that small too. You would think cooling would be an issue, but NISMO engineers have just got onto it, with the system working well at Le Mans.
With much of the bodywork it’s possible to note the turbocharger layout and design. The air cooler is mounted directly under the turbo separated by just a small aluminium plate which surprisingly seems to lack any kind of thermal shielding like you see in the world of F1 manifolds. The front suspension layout and drive shaft can also be seen with steel upper and lower wishbones. Note no ERS of MGU as it’s only taken from the rear wheels only on the Nissan.
With the front bodywork removed, you are able to note the ancillary drive system mounted on the back of the gearbox as well as the layout of the front rockers and spring damper set up
At the very tip of the car is the drive belts and the beautifully sculpted aluminium mounts. This looks more like art that last 24 hours type of thing. When it’s removed you are able to witness the Tilton Clutch, which surprisingly is not mounted between the engine and transmission, but at the very tip of the car, which is why you see lots of structure to protect it.
While the three litre V6 was working well at Le Mans, the rear mounted Hybrid system failed to work. Unlike its other LMP1-L rivals, the Nissan bases much of its Hybrid system of a mechanical design, rather than an electric one. The energy is stored in two contra-rotating flywheels, mounted along with their transmission into a control box at the front of the monocoque under the driver’s legs. The position has therefore given the driver’s a very low stance in the cockpit.
The housing of the system is very large and bulky, it transmits drive to the rear wheels via a large axle which runs right through the centre of the chassis. Not an obvious approach and sadly one that deemed not to work.
Mounting the unit into the car caused several issues, firstly because NISMO engineers took technical regulations differently, this led to a minor redesign of the chassis which made them miss the start of the WEC campaign. The whole unit had to be installed via the front windscreen, a complex and annoying job NISMO engineers claim. The hybrid system was not able to be utilized at Le Mans, something that disrupted the tyre ware, overworked the front brakes which therefore changes the philosophy that car had to run it, it wasn’t optimized for racing in a twenty four hour race, the car just wasn’t suited.
Once the drive from the Hybrid system had reached the rear of the car via the centre mounted axle, it would pass through a differential and onto Copper like driveshafts. But here there was an a big issue, as the images state clearly the air ducts through the car sit exactly where the driveshafts would need to run to the rear wheel uprights and braking system. So an unseen linkage using a number of joints was apparently created to get the drive to the rear wheels without the need for shafts in the ducts. This to me sounds complex as well not being very strong. Contact would surly bent the linkage, something other rival teams would have to worry about with their strong drive shafts.
When the car was at COTA testing, a new wing mirror was introduced. (Below left) shows the new design (below right). They are mounted further out than before. The team’s drivers tented not to use them, and opted for the centre console rear-view cameras instead.
Also at COTA, the car ran its high downforce aerodynamic package. Before saw a bare front nose structure and low rear wing angle. But (below) the car ran twin dive planes on the leading edges of the car, which helps to stop the front end of the car diving downwards in the braking zones. These play an important job with flow management too.