Porsche's 918 Spyder eAxle System - Engine Builder Magazine

Porsche’s 918 Spyder eAxle System

Part of what makes the 918 Spyder so revolutionary is its hybrid and plugin capability, which enables performance not attainable from a normal setup. The highly advanced eAxle system used on the 918 Spyder was developed in conjunction with Swedish firm and drivetrain industry leader GKN. The eAxle that supplements the 918 Spyder’s hybridized 4.6-liter V8 is an evolution of the company’s innovative eAxle drive.

GKN_eAxle_Porsche_918_Spyder-e1423678835783The Porsche 918 Spyder is one of the top performing and most sought after supercars in the world. Part of what makes the 918 Spyder so revolutionary is its hybrid and plugin capability, which enables the car performance not attainable from a normal setup. The highly advanced eAxle system used on the 918 Spyder was developed in conjunction with Swedish firm and drivetrain industry leader GKN. GKN’s eAxle module supports full-electric mode and all-wheel drive and provides a boost function.

Porsche power-train head Christian Hauck commented on the system:

“Realizing our vision for a super sports car capable of setting a record lap time of the Nurburgring and of achieving fuel efficiency of three liters per 100 km placed huge demands on our engineers and suppliers. GKN Driveline’s role in the development programme and its innovative eAxle module has earned the company Porsche Technology Partner status.”

The eAxle that supplements the 918 Spyder’s hybridized 4.6-liter V8 is an evolution of the company’s innovative eAxle drive. The module has maximum power of 95kW and can deliver up to 1500Nm of torque to the front wheels via a fixed gear ratio. A specially developed compact differential engages the torque seamlessly, giving the 918 Spyder optimum power distribution at all times. The differential also disengages the module to minimize drag losses and maximize efficiency. At speeds above 164 mph, a clutch isolates the electric motor to prevent it from over-spinning.

A key target for the 918 Spyder was to have the lowest possible center of gravity and ground clearance. To achieve this required an original engineering solution: GKN positioned the output overhead, using an innovative lubrication concept to manage the oil flow.

porsche-918-e1423678917572The oil reservoir is positioned above, not below, the gear-train. Oil is gravity-fed down onto the bearings and gears until it reaches the high-speed input at the bottom where it is then circulated back to the oil reservoir at the top. This design minimizes the amount of oil on the input shaft, keeping churning losses to a minimum. To ensure the critical areas remain lubricated even in disconnect mode, the motor is driven for brief, intermittent intervals to maintain a constant flow of oil. The Porsche 918 Spyder’s tight packaging also means there is almost no air flow around the transmission and so water cooling was needed to manage the heat generated by the module’s high power density.

GKN also aided in the axle and torque vectoring components used in the all-wheel drive systems found in the Range Rover Evoque, as well as the Ford Focus RS. The latter vehicle’s system is scheduled to become standardized as an option on many future Ford Performance models.

You May Also Like

Fuel Additives Address Diesel Deficiencies

Advancements in diesel fuel additives continue to play a pivotal role in improving the performance and efficiency of diesel engines.

diesel fuel additives

Diesel fuel is a perfectly imperfect product. Yes, there is the industry standard specification ASTM D975 that outlines minimum performance requirements. But, this mostly confirms that refiner A in the Gulf Coast produces diesel fuel with the same baseline characteristics as refiner B in the Midwest.

Gasoline, on the other hand, has to meet a Federal Lowest Additive Content, or LAC, mandate that ensures every grade includes a certain amount of detergent and satisfies all gas engine-related emissions requirements. That also helps keep fuel injectors clean and catalytic converters in working order.     

Shop Solutions May 2024

Those who submit Shop Solutions that are published are awarded a prepaid $100 Visa gift card. Submit your Shop Solution at [email protected].

Shop Solutions April 2024

Shop Solutions provide machine shop owners and engine technicians the opportunity to share their knowledge to benefit the entire industry and their own shops.

A Different Dyno Design

The dyno is a valuable tool, so it’s nice when an engine builder feels confident in the setup of it. Enter the shipping container engine dyno design.

Properties of Pistons

Pistons are perhaps one of the more sophisticated chunks of metal in the picture. Here’s what you should know.

Other Posts

Liqui Moly Sponsors World’s Largest Porsche 356 Gathering

Promoted annually with the seal of Porsche AG and the Official Porsche Club, the International Porsche 356 Meeting takes place on a rotating basis in several countries.

Porsche Motorsport to Launch USAC-Sanctioned Endurance Series

Each round will feature a category for the Porsche 911 GT3 Cup car and a class for the Porsche 718 Cayman GT4 RS Clubsport.

A New Take on the Rotary Engine

What if we could design a new rotary engine that addresses certain limitations without violating the laws of physics? This is what LiquidPiston has been working at for over a decade.

Perfecting Ring Seal Soup

Using modern honing machines, surface finishes, crosshatch angles, ring materials, and coatings all combine to create a more efficient engine.