Lexus raises the ante with the F-series

By March 31, 2011

Lexus went after the German luxury car makers in 1991 and quickly became a major player. Manufacturers aren’t afraid to copy each other, so when BMW came out with their M-models, Mercedes Benz responded with the AMG label, Lexus created the F-models, which are supposed to have some extra juice.

The first F-model is based on the IS sedan which is roughly the size of a BMW 3 series. So the IS-F is up against the heavy machinery such as the BMW M3 and Mercedes Benz C63. If you are going up against the best of the best, you need to be better than just good. We managed to get our hands on an IS-F to see just how good it is.

To be successful in this segment you must have plenty of power. The IS-F is powered by a state-of-the-art 5.0 liter DOHC V8 that uses the latest technology — 32 valves, direct injection, and a very high 11.8:1 compression ratio. Lexus uses electronic variable valve timing with intelligence on the intake side camshafts. An electric drive motor alters the intake camshaft phasing, which made it possible to expand VVT operational range to lower engine speeds, where engine oil pressure is usually not high enough to operate conventional VVT.

More conventional hydraulic VVT-i is employed on the exhaust side camshafts. The combination allows the 2UR-GSE V8 to rev to 6,800 rpm and crank out 416 horsepower at 6,600 rpm and 371 pound-feet of torque at 5200 rpm.

The forged crankshaft features journals polished to a mirror finish to minimize the friction generated between the connecting rods and the crankshaft. Forged sintered iron-alloy connecting rods ensure high-rpm durability. High-flow cylinder heads designed by Yamaha have a lightweight valvetrain, including forged cam lobes on hollow, chain-driven camshafts, with the inside of the shafts serving as oil passages. Titanium intake valves are operated by roller rocker arms.
Innovative technologies help to maximize efficiency and reduce emissions, including the SFI D-4 fuel injection and the Electronic Throttle Control System with intelligence. Essentially, SFI D-4 integrates two types of fuel injection: A direct-type high-pressure fuel injection system, which provides a cooling effect in the cylinders and enables the high compression ratio employed to extract maximum energy from the fuel with a set of low-pressure port fuel injectors that help produce a precise burn to optimize power and efficiency under light- and medium-load conditions.
A dual air-intake system uses a primary intake passage for low and medium engine speeds. In the higher engine speed range (above 3,600 rpm), both the primary and secondary passages are opened, helping boost high-rpm power.
Many high performance cars can corner well enough that on a race track, but the high-G-force loads pull the oil away from the pickup tube in the oil pan. Lexus uses a scavenge pump which forces oil from the cylinder heads back to the oil pan, ensuring a reliable oil supply even during cornering that exceeds 1 G. The low-restriction dual-exhaust system terminates in distinctive stacked quad tail pipes.
The world’s first eight-speed Sport Direct-Shift automatic transmission is the sole transmission choice in the IS-F. The transmission is supposed to combine the performance characteristics of an automated manual-type transmission with the smoothness and refinement of a planetary-type automatic transmission. As a result, the driver can choose between ultra-quick manual shifts for performance driving and smooth automatic shifts when convenience is the top priority. The eight speeds allow the transmission to use very close ratios with a super short first gear.
The driver can shift manually using either the console shift or steering-wheel-mounted paddle shifters. New hydraulic-control technology allows the IS F’s eight-speed Sport Direct Shift transmission to perform on par with manual transmissions without sacrificing the smoothness of a torque-converter automatic.

Paddle-shifting operation is allowed in either D or M modes, but shifts are quicker and more direct in M mode. In M mode, the transmission will hold each gear to the 6,800-rpm redline, and upshifts are executed in just one-tenth of a second. At higher engine speeds, downshifts are accompanied by automated and precise throttle blips to match engine rpm to vehicle speed.

The system works well but the super-short first-gear ratio along with the huge power causes the engine to hit the redline in a hurry. Fortunately there is a sequential shift light built into the tachometer. You need to practice because by the time you see the redline, it is too late for an upshift which causes the computer to kick in the rev limiter and it takes a few moments to get the power back. The quick shifts in manual mode under full throttle feel fabulous and the engine at wide open throttle sounds like a monster which will bring a smile to your face every time.

A traditional manual transmission would make the IS-F easier to drive at speed. The high-tech transmission often is slow to respond, and once it finally decides to downshift, it results in a surge of power which is more than you wanted. The transmission would probably work well on a race track where you plan your moves but if you are just driving and suddenly decide to make a quick pass by flooring the throttle, the delay is just irritating.

If you want your car to handle well with all that power, you better start out with a stiff body structure. The already stiff body of the standard IS is further reinforced on the IS-F. Much of the IS-F development took place at racetracks around the world, including Germany’s legendary Nurburgring Nordschleife, Circuit Paul Ricard in France, Japan’s Fuji Speedway and the Higashi-Fuji Technical Center in Japan. Fuji Speedway is the IS-F’s home circuit, and the shape of its turn one inspired the F-logo design.
Although using the basic double-wishbone front suspension and multi-link rear suspension configurations of the IS platform, the IS-F features a multitude of track-proven modifications. The IS-F sits an inch lower on its suspension than the standard IS models, which lowers the center of gravity and helps provide a quicker handling response.
Spring and damper rates are increased, and larger-diameter stabilizer bars are used. The rear-suspension control arms are specific to the IS-F to optimize geometry for the 19-inch wheels. In addition, the monotube shock absorbers use a larger-diameter piston rod.  
Front 19-by-8, and rear 19-by-9 wheels shod with Bridgestone Potenza 225/40R19 and 255/35R19 tires were selected specifically for the 170-mph track capability of the Lexus IS-F. The IS-F has been bred to drive on the track. The engineers installed high-rigidity hub unit bearings which are designed for rigorous, high G-force track driving. They even program the tire pressure monitoring system to allow two sets of tires to be registered, giving the customer the benefit of a system with a set of track tires or winter tires.

All of the engineering works great and the IS-F handles like a well-behaved race horse. There is so much grip on the road that you really can’t exploit the limits on public streets without risking your license. The power is intoxicating and you will giggle every time you drop the hammer. The driver is faced with a beautifully simple yet gorgeous instrument panel with a huge center mounted tachometer with built in digital speedometer and sequential shift lights. All sports cars need to take a lesson from the IS-F.

The IS-F may be fast, but it’s still a Lexus so it has to be luxurious as well. Standard amenities include 10-way power front seats; dual-zone automatic climate control, a pollen filter and smog detector; power moonroof with one-touch open/close and seven open-position settings; power tilt-and-telescoping steering wheel; three-position memory function for front seats, steering wheel and mirrors; all power windows with automatic up/down operation and jam protection; an auto-dimming rear-view mirror with HomeLink programmable garage door opener; automated rain-sensing wipers and heated auto-dimming outside mirrors with integrated puddle lamps. There are also some very supportive front seats with heat that work well on the longest trips. The back seat holds only two people and there is not a lot of legroom so if the front seats are pushed all the way back.

Our car also came with the optional $2,500 navigation system that features a 7-inch touch screen. It’s very easy to use but unfortunately Lexus lawyers seem to be paranoid, since most of the functions, even some basic ones, are not available when the car is moving. It is amazing to see that the driver is trusted with a 416-horsepower cruise missile, but not with being able to change from miles to kilometers on the navigation screen unless the car is stopped.

The IS-F isn’t cheap, with base prices starting at $59,000. But for those with large enough wallets, it can bring a lot of smiles for years to come. There are a lot of great cars out there competing for your hard-earned dollar — some may have more room or more power but the balance of the features and the engineering behind the IS-F is certainly impressive. Lexus has done a fantastic job creating a car that can compete with the big guns and the IS-F is a must-test for anyone shopping for a sports sedan.

Ali Arsham

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