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The Birth Of The IS-F
Originally the IS F was not part of any long-term strategy or corporate aim. It began with the enthusiasm of two engineers, Yaguchi-san and Sakamoto-san. Their personal enthusiasm for high performance had already led them to experiment with an older model IS 300. With the debut of the new IS they continued to work upon advancing every aspect of the dynamics, while at the same time lobbying heavily at the highest management levels for support.
This level of commitment and expertise paid dividends. As the project grew and was presented to the higher executives, so internal feedback became more positive. The result was that in 2004 they were given the goahead
for what had already become known internally as the ‘F’ project.
Intense media, customer and distributor interest at the 2007 Frankfurt launch merely confirmed what many in the company already suspected: That the time was right for a real high performance challenger bearing the Lexus badge.
To create the IS F several questions arose. The principle one is obviously what exactly a committed driver actually wants from his car. In fact what basic elements create driving excitement on the road and track? From this three wider areas of research arose: response: handling, engine and transmission response, sound and a feeling of unlimited acceleration
Response
For a really discerning driver to fully enjoy the performance of his car three elements come immediately into play. Acceleration, braking and steering. The more directly the car responds to the driver’s input, the more satisfying the experience becomes.
To power this dynamically refined response Lexus engineers developed a compact 5-litre V8 engine with advanced D-4S direct fuel injection, VVT-iE, hollow overhead camshafts, and electronic throttle, delivering 423 DIN hp. To ensure constant power delivery, even during 1G lateral acceleration turns, both a small fuel surge tank and high mounted oil scavenge pumps are fitted. Elsewhere racing technology also featured in the forged crankshaft, sintered con-rods and ultra rigid block casting techniques. The result is an engine which delivers instantaneous response anywhere in the rev range, giving the impression that the linear acceleration is virtually unending.
More important is the drivers feeling of control over this power. By developing the world’s fastest 8-speed Sport Direct Shift (SPDS) transmission, which shifts in just 0.1 seconds, Lexus engineers delivered the kind of direct response formerly only found in motor sport. A major benefit of this transmission is that in M-mode the driver has complete control over these changes, and can hold any gear, using racing type paddles. However,
for heavy traffic or relaxed cruising, in D-mode it performs like a normal (albeit very direct and precise) automatic transmission.
Full lock-up control is used during both acceleration and deceleration in 2nd gear and higher, without using the torque converter function. This enables changes in engine output to be transmitted directly, just like a manual transmission. If, however, engine speed is too low to allow lock-up, the torque converter function will also be used in 2nd gear and up.
The response and weight of the steering has also been fine-tuned for high performance driving. A new type of VDIM (Vehicle Dynamics Integrated Management system), automatically adjusts the setting of the power steering when the VDIM Sports mode is selected.
Also both the brakes and suspension were uprated. In fact detail lightening and modification of the suspension, brakes, wheels and tyres has reduced unsprung weight resulting in sharper, more directly responsive handling.
Sound
Finding the right sound for any exclusive car is a skilled and painstaking procedure. As a highly emotive area, the actual sound of the engine received high priority in developing the IS F. The car’s highly significant aural sound design falls into three distinct categories. In the low and medium speed range, the V8 engine creates a strong exhaust sound, while maintaining overall tranquility. When the higher speeds are reached, the second intake port opens, and the engine sound changes suddenly to an impressively powerful sound. As the engine approaches the maximum speed range, only the polished and pure mechanical sound of the engine can be heard, intensifying in synchronisation with the engine speed.
Acceleration
A car that accelerates, and then just goes on accelerating is the dream of many highly motivated drivers. To achieve this smooth and seamless feeling the size of the engine, the lightness of it’s construction and the whole relationship between power, transmission and handling must be perfectly optimised with the overall weight of the vehicle. In delivering this accelerative performance the actual track testing of the IS F, and the finely honed skills of some of the best test drivers in the world, have refined all of these aspects to produce both acceleration and a superbly balanced feeling of perfect control.
PRESS RELEASE: 24/01/2008
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