Funny how status can change. Time was when the Lexus IS-F was the rake of the family, the athlete from a family of artists. Then comes the Olympian and the jock, along with the shirt-ripping biceps and state championship sprint, becomes suddenly ordinary. Alongside the Lexus LFA, the IS-F is a couch potato.
Perhaps, but dang, boy, the Lexus IS-F has a 416-horse 5.0-liter V-8 stuffed into an engine compartment tailored for a 3.5-liter V-6 and the various bits barely fit within the sheetmetal. The grille is bigger, the tires wider and barely contained by swollen fenders, and it has twice the number of exhaust outlets. The IS-F rides an inch lower than its lesser IS siblings. No one, and not just car enthusiasts, will see the IS-F as anything by a performance car, even if a kickass version of a sports sedan.
For the 2011 model year, the Lexus IS-F had its suspension tweaked for 2011 for “more driver confidence” (firmer springs and increased camber at the rear), the electronic power steering updated and, most significantly, the rear differential replaced by a Torsen torque-sensing unit. The IS-F was already equipped with a cornering stability program that reduced inside rear wheel spin by dragging a brake on that side. The Torsen now transfers torque to the side with more traction mechanically.
Compared to the garden variety Lexus IS, the spring rates and shocks are stiffer and Lexus installs thicker anti-roll bars. The rear-suspension control arms were replaced to accommodate the 19-inch wheels, which are wider at the rear than the front, with tires to match. Tires, either Michelin Pilot Sport PS2 or Bridgestone Potenza, were selected for 170-mph track use. The Lexus IS-F has two registers for the direct-reading tire pressure monitor system, allowing track or winter tires to be swapped out with the standard tires.
The stability control system is specifically calibrated for the IS-F and integrates the various braking, steering and throttle control systems, including a Sport mode that tells the nanny to back off. Brembo brakes were engineered to Lexus’ specifications, with six-piston aluminum calipers up front and two-piston at the rear. The huge brake rotors are drilled and vented, with brake ducts next to the fog lamps to direct cooling air to the front discs.
The 5.0-liter V-8 continues as was. The high revving engine—and a high-performance V-8 approaching 6800 rpm makes a sound not easily forgotten—has Yamaha-designed high-flow cylinder heads with a lightweight-design valve train. Titanium intake valves have roller rocker arms, and the hollow camshafts transport lubricating oil to the forged cam lobes.
The fuel delivery system includes direct injection with a secondary port fuel injection system. Direct injection allows an 11.8:1 compression ratio while Lexus says the low-pressure fuel injection helps “produce a precise burn to optimize power and efficiency under light and medium-load conditions.”
For low and medium engine speeds, only the primary intake tract of a dual-intake system is used, but above 3600 rpm a secondary passage is opened for high rpm air flow.
Unlike most other variable valve timing systems, the Lexus IS-F’s works via an electric motor rather than hydraulics, which means it can turn the camshafts even at lower rpm where there often isn’t sufficient oil pressure for a hydraulic system to work.