Powertrain Solution for Official State Cars

Recently, the company NAMI has presented its new car intended for state officials. This luxury car is named Aurus Senat. The new presidential car belongs to the 'Project Kortezh' (officially named as the Unified Modular Platform), which was developed by the Russian State Research Center “NAMI” for manufacturing of vehicles intended for transportation escort of top public officials and other persons who come under state protection. All cars related to this platform will be produced under the brand Aurus. NAMI will be assisted by the automotive company Sollers in implementation of this project and selling of cars.

The main modifications of the 'Project Kortezh'

The product portfolio of the “Project Kortezh” includes limousines Aurus-41231(SB)/41231, sedans Aurus-4123, SUVs Aurus-4124, minibuses Aurus-4125 with long and short wheelbases. The models have the following names: sedan and limousine – “Senat”, minivan – “Arsenal”, SUV – “Komendant”.

Recently the photo of the minivan Arsenal got leaked to the press

The flagship of this product range, armored limousine Aurus-41231, is 6840 mm in length. It is expected that vehicles of the “Project Kortezh” will hit the open market in the first quarter of 2019.

Powertrain solutions

Engine

NAMI engineers independently developed the flagship power unit for the presidential limousine. The capacity of a huge V12 engine equals to 6,6 liters. The indicated horsepower of 860 hp is complemented with 1300 Nm of torque. However, the torque value is limited to 1000 Nm, so the engine could be integrated with the 9-speed automatic transmission.

V12 engine for the “Project Kortezh”

In the engine, NAMI engineers implemented the direct fuel injection system and twin turbocharging system (actually, the engine has 4 turbines). The engine has the following dimensions: length- 935 mm, width - 813 mm, height - 860 mm. The engine dry weight amounts to 310 kilograms. The engine lifetime without the overhaul may reach up to 350 000 kilometers.

Transmission

The "Aurus Senat" limousine is equipped with the 9-speed automatic transmission R932 designed by the Russian company KATE in collaboration with NAMI. The main difference between the R932 and other automatic transmissions for luxury cars is lack of the torque converter. Engineers of modern hydro-mechanical transmissions work on solutions where the torque converter is locked up as early as possible in order to increase transmission efficiency and reduce fuel consumption. NAMI just made the next step and excluded the torque converter altogether. Such solution has already found application in track-type vehicles.

R932 showcased at the exhibition

Nine gears allow selecting of an optimal gear ratio within a wide range – from 5,732 (in the 1-st gear) to 0,661 (in the 9-th gear), i.e. the gearbox does not require the torque converter to increase the possibility of changing gear ratios. The electronic control system (ECU) helps to shift gears at the appropriate times, thereby minimizing slippage of friction elements. This car transmission has 4 planetary gear sets which are controlled by three brakes and 3 clutches. These components are driven by hydraulic actuators, so the traditional hydraulics in design is preserved. The flow of ATF is controlled by solenoid valves, which in turn are controlled by the ECU.

The development of this car transmission was started in late 2013. Around the same time, engineers adopted the gearing diagram and started developing mathematical models on computers. It was required to find optimal algorithms of gear shifting in different operation modes of the car. The first prototypes, which were tested with the help of the bench testing unit, appeared in late 2015. The R932 transmission is designed for operation in combination with the most powerful engines within the project of the Unified Modular Platform (UMP) – in particular, V12 with operational capacity of over 850hp and V8. The maximum torque of the V12 engine examined above equals to 1470 Nm, but the R932 transmission is limited only to 1000 Nm of torque. In this case, engineers had to strike a balance – increase of the torque capacity would lead to enhanced dimensions and greater weight of the transmission; the transmission torque capacity of more than 1000 Nm would also go beyond restrictions on road-holding. Therefore, engineers decided to limit the engine torque to 1000 Nm, so the car could move without stalling and without transmission overloads. The torque capacity of 1000 Nm is quite an impressive characteristic which can be rarely found in series produced cars.

In fact, it is possible to combine the automatic transmission R932 with less powerful engines, such as V6 or even four-cylinder engines. However, the R932 seems too large and weighty for these engines. In addition, according to the UMP policy different products have various application purposes: some products (engines and transmissions) will be supplied for cars intended for state organizations, others – for cars which will be available on the global market. Therefore, the automatic transmission R932 will never become a mass product simply because of its purpose. Most of cars equipped with this transmission will find their place in special purpose garages. All in all, new powertrain solutions designed by NAMI and KATE are quite remarkable and have a strong potential.

ABOUT KATE

The Russian company KATE, established in 2004, is specialized in manufacturing of automatic transmission. In 2006, KATE showcased two automatic transmissions (FT703 and RL608) at the International Auto Show. The FT703 is intended for front-wheel drive cars with transverse engine mounting. According to different data, this transmission has the torque capacity of 150 or 175 Nm. It can be combined with engines having the power of up to 127 hp. The main peculiarity of this 7-speed automatic transmission is lack of the automatic transmission torque converter – even at that time KATE engineers considered this solution to be the key to reduce dimensions and total weight of the transmission.

The second gearbox RL608 has more traditional design which includes the automatic transmission converter. This automatic transmission is suitable for rear-wheel drive cars and their modifications with four-wheel drive. The RL608 is capable of transmitting torque of up to 300 Nm. It was planned to build a new plant for manufacturing of this automatic gearboxes. The estimated production capacity of this plant will amount 260-300 thousand of different car transmission models per year. However, the plant construction has not been started yet.

ABOUT NAMI

Today, NAMI has got highly qualified production and technical personnel, advanced production and development base that allows addressing the most challenging tasks in the field of research, design, manufacturing, and testing of motor vehicles. In its long and reach history, NAMI went a long development path of all industrial fundamentals and plans to keep its development pace as an industrial, engineering and regulatory center, applying 95 years of experience in the field of R&D and development of the automobile industry. Nowadays, NAMI has a great potential for growth, being a modern R&D center with capacities for design, manufacturing and testing of automobile platforms.