Lexus’ new supercar, the race-bred engine, is the heart of Lexus and off-limits to the rest of the model range. And according to ex-F1 engine designer, Takamitsu Okamoto, that’s the official line from the powerplant’s designer.
According to Okamoto, whose portfolio includes engines of the Le Mans Group C prototypes, Group B rally cars, CART turbo V8s and F1, the hand-assembled V10 is simply too expensive to be used in other Lexus models.
Yamaha, the motorcycle specialist, has assembled the compact race-style dry-sumped V10 and features a block that is cast and machined by Toyota’s own F1 operation in Toyota City in Nagoya, Japan.
Design of the engine places oil, water and scavenger pumps at the rear of the engine for compactness while the power steering and aircon units like ancillaries are mounted low on the front of the power unit to allow servicing.
The engine V10 is smaller than the V8 used in Lexus’ only other dedicated performance model, the IS F, says Okamoto, and also added that it is more expensive to build.
Lexus engine’s internal use includes titanium rods and valves, and forged alloy slipper style pistons. The engine’s rocker covers are magnesium and the headers are works of art in stainless steel.
Instead of steel or alloy cylinder liners, the V10 takes a leaf out of motorcycle engineering text books and uses a ‘thermal sprayed’ cylinder coating.
The F1 engine inspired the new LFA powerplant has the potential to rev significantly higher than its current 9000rpm limit save for the “heavy” variable valve timing hardware, Okamoto says.
THE engine would likely feature fixed cam timing in a race application, which would dispense with the mechanism.
Its peak torque is substantial at 483 Nm, though not in the league of cars like Benz’s new SLS. And according to Okamoto, the torque could be boosted if the engine was used in an application that demanded it.
New Toyota boss Akio Toyoda’s patronage, and his belief that the LFA is a halo car Lexus needs, appears to have been crucial to the car’s fortunes. Lexus insiders suggest even over a short two-year life span its money well spent, despite the high cost.
