To sharpen the car's circuit driving performance even further by increasing downforce at high speed, the Nurburgring Package introduces modifications and additions to several key carbon fiber reinforced plastic (CFRP) components. These include a larger front spoiler, fin-type side spoilers, a canard fin and a fixed rear wing. To ensure the LFA maintains its 3.7-second acceleration time from nought to 62mph, in spite of the increased drag, the V10 engine has been revised to increase maximum power by 10bhp to 562bhp. Shift times in the six-speed sequential transmission are just 0.15 seconds.
In terms of handling modifications, the package features suspension tuning and a 10mm reduction in the ride height. Exclusive mesh-type wheels are introduced, fitted with dedicated high-grip tires. Exterior color choices are restricted to matte black, black, white or orange, with interiors finished in black and red, black and purple and all-black. Cars delivered in Europe will feature a carbon fiber center console and door trims, with carbon fiber sports seats finished in Alcantara.
Customers who specify the package will also be offered one-to-one driving tuition from a Nurburgring chief instructor and a year's pass to enjoy their car on the famous Nordschleife circuit.
CFRP parts manufacturing
LFA production began in December with just one hand-crafted car completed per day. A team of 175 people are involved in CFRP parts manufacturing, vehicle assembly and painting.
CFRP is exceptionally strong, rigid and lightweight, and accounts for about 65 per cent of the LFA's body structure weight. This amounts to a saving of about 100kg, compared an equivalent all-aluminum body.
Lexus is producing and assembling the CFRP components in-house, with a view to future development of the technology. It is a time-consuming process, compared to working with steel or aluminum, but the LFA project provides a valuable test bed for new, automated processes which will be used in the manufacture of future Lexus and Toyota models.
Different manufacturing technologies are used according the shape, role and required properties of each component.
-Pre-preg: this is an industry-standard composite sheet material made of carbon fibre, pre-impregnated with epoxy resin. It is used for the LFA's main structural elements, such as the dash, side and cross-members and panels.
-Resin Transfer Moulding (RTM): this is dry sheet fabrication, with epoxy resin injected into the mould. It is mainly employed in the LFA's secondary main frames, such as the crash boxes, roof side rails and vehicle floor.
-Carbon fibre - Sheet Moulding Compound (C-SMC): this is used for fabricating the upper body components and frames that have complex geometries.
The LFA assembly line moves through five consecutive processes, each of which has been digitally validated. For the first four - sub-assembly, underbody, small aluminium parts and main body - adhesive bonding is used. Final assembly of the aluminium parts is by mechanical fastening.
This is the first time Lexus has used adhesive bonding for main body assembly, a process that has required new quality control measures to be implemented to ensure each of the five stages involved in the bonding meets the required criteria.