The Lexus LFA supercar – the long awaited production version arrives
By Darren Quick
October 25, 2009
It’s been a long time coming. The Lexus LFA that first appeared as a concept car at the 2005 Detroit Auto Show is finally production ready. Lexus made the announcement at the 2009 Tokyo Motor Show where a prototype of the production car was on display along with a full-scale see through model in the company's “art gallery” - and the stunning 202mph V10 supercar is indeed worthy of a place in an art gallery, although keen collectors will still have to endure a bit more of a wait since the car isn’t expected to reach garages until early 2011, with only 500 units being produced.
To achieve the car’s 2.64 kg/PS power-to-weight ratio Lexus has managed to keep the LFA’s weight to a total of 1,480 kg (3,263 lbs) largely thanks to the rigid carbon fiber reinforced plastic cabin at the LFA’s core, which is approximately 100 kg (220 lbs) lighter than a comparable aluminum unit.
With the engine being the heaviest component in a vehicle Lexus has also made a significant reduction in the overall weight of the LFA by reducing the engine’s mass. By using materials such as aluminum, titanium and magnesium, the LFA’s V10 engine manages to adopt a profile smaller than that of a conventional V8 without sacrificing performance. Assisted by a 12:1compression ratio, low friction internals and optimized airflow, the LFA achieves an output-per liter of 85.7 kW/L (117 PS/L).
Critical to the car’s performance is not just how much it weighs, but also where that weight is placed. To help ensure a low moment of inertia that means less effort is required to turn the vehicle Lexus has located the heaviest components, such as the transmission, engine and fuel tank, within the wheelbase so they are closer to the vehicle’s center of gravity. The oil and water pumps are mounted down and towards the rear of the engine to reduce the amount of weight of the front wheels, while the transaxle, the second heaviest component in the vehicle, is positioned directly on the rear axle.
Lexus says the front-mounted engine and rear-mounted transaxle configuration gives the LFA a 48:52 front/rear weight distribution that combines the controllability and straight-line stability of a front engine rear wheel drive (FR) platform with the cornering performance of a mid engine rear wheel drive (MR) platform, but with exceptional handling ability.
The LFA’s handling is assisted by its low center of gravity, which Lexus claims is lower than that of a “normal sports car”. The vehicle’s dry sump lubrication system employs a slim oil sump, which allows the engine to be moved closer to the ground, while the low floor, with a minimum ground clearance of 115 mm (4.5-in), also contributes to the low center of gravity.
The driver position as close as possible to this center of gravity. The drivers seat sits between the front and rear axles and, thanks to vertically stacked exhaust pipes closer, the narrow center tunnel also allows a position closed to the center.
Lexus has replaced the conventional single throttle body with independent electronically controlled throttle bodies that dramatically enhance intake efficiency by creating a minimal body of air between each throttle body and its respective combustion chamber. This effectively halves engine response time, with the response of the LFA so fast that when the accelerator is released, the revs drop too quickly for a traditional analog tachometer needle to keep up. Therefore, Lexus has used a full-color TFT LCD panel graphical tachometer that features a rev peak-hold function, lap timer and a variable redline display.
The paddle shifters of the LFA have been designed so that the force required to operate them varies between upshifting and downshifting, with the downshifting paddle requiring a greater degree of force than the upshifting paddle. Sounds like a good idea that could provide an extra touch of differentiation between upshifting and downshifting. Lexus also says “the downshift paddle has a higher force pull to foster a sense of excitement upon each downshift.“
To provide consistent and effective braking under any conditions the LFA employs an electronic controlled braking (ECB) system. Conventional brake systems use vacuum from the engine to control a brake booster that multiplies the driver’s own brake effort. However, this means that overall brake performance and effectiveness will vary depending on the amount of engine vacuum present at the time. In comparison the LFA’s ECB system uses an electric pump to generate hydrologic pressure, thereby providing consistent braking power without relying on engine vacuum.
The state-of-the-art components extend to the aluminum remote-reservoir monotube shock absorbers developed exclusively for the LFA to deliver smooth and precise damping. Their piston rods are coated in a Diamond-Like Carbon (DLC) compound and the main cylinder walls are Ni-Si plated. The remote reservoir cylinders employ metal bellows (expanding and contracting sections) connected to the main cylinder via base valves.
Lexus has sought to refine every aspect of the LFA – right down to the sound of the engine, which it likens to a precisely tuned musical instrument. In fact, the resonant frequency of the surge tank has even been tuned to a richer intake harmony to give the LFA its signature note. Unfortunately only a privileged few will get to enjoy such a symphony in person - Lexus will only be producing 500 of the cars and each will attract an asking price of US$375,000. As expensive as that sounds, apparently Lexus expects to make a loss on each one.