Maximising the McLaren LT experience

The Longtail name became legend nearly a quarter of a century ago, when an extreme lightweight version of the Le Mans-conquering McLaren F1 GTR race car, wearing a stretched body, swept all before it in the 1997 FIA GT Championship. The principles behind that car – ultra-low weight, enhanced aerodynamics, extreme performance and absolute driver engagement – were revisited in 2015 when McLaren introduced the 675LT.

The new 765LT Spider, like its predecessors, stays true to those Longtail principles, placing the driver at the very centre of the sensory, dynamic and – especially in this case – aural experience, the triple-patented Retractable Hard Top roof taking driver engagement to an ever-higher level.

The Retractable Hard-Top is constructed using a single carbon fibre frame featuring a high-density, noise-reducing foam core between the panel and the internal headlining. This removes mass from the upper section of the car as well as reducing the volume of unwanted noise inside the cabin. It also creates more headroom for occupants by removing the central seal that previously ran side-to-side across the roof panel.

The roof mechanism of the 765LT Spider is among the world’s quickest and quietest Occupants will experience a sound no louder than 50 dBA during operation, with a peak of 60 dBA during the latching process – twice as quiet as the roof of the 675LT Spider, the first convertible LT supercar. Fully electrically controlled, the roof can be opened or closed in just 11 seconds, at speeds up to 50km/h. The system is powered by eight electrical motors – two to fold the roof panel, two to raise and lower the tonneau cover and two to control the dynamic flaps which deploy on the tonneau buttresses when the roof is open.

The front splitter, new front bumper, lower door blades and side skirts, wraparound rear bumper and active rear wing are all made of carbon fibre and bespoke to the 765LT. The bonnet, front fenders, outer door panels and rear fenders – which are in lightweight aluminium as standard – are also available in body-colour carbon fibre as MSO Defined options. The front fenders reduce weight by a total of 1.2kg, the rear fenders and door panels together by 4.9kg.

The one-piece carbon fibre front floor, constructed at McLaren’s Composites Technology Centre (MCTC) near Sheffield, UK, is notably unique; extremely light and stiff, it not only optimises the aerodynamic performance of the revised underbody – further reducing inertia – but also allows the front end of the Spider to be common with the coupe.

Every McLaren is designed to a philosophy of super-lightweight engineering, to the point where further reducing weight is extremely challenging. The 720S Spider from which the 765LT Spider is developed weighs just 1,468kg and boasts a better power-to-weight ratio than any of its competitors. But the Longtail ethos has always demanded relentless pursuit of lowering weight:  the original F1 GTR was unthinkably light for its day, but the F1 GTR Longtail was more than 100kg lighter still. True to the LT bloodline, at 1,388kg (DIN) the new Spider shaves 80kg off the DIN weight of the 720S Spider.

The rear window, which can be lowered even when the roof is up to intensify the quadrophonic exhaust note, has its own motor, as does the RHT latching mechanism. All these motors are optimised to work in parallel, allowing the roof to begin to move before the tonneau has completely opened, which saves time. The 675LT Spider’s roof – which took 17 seconds and operated at speeds of up to 30km/h – was controlled by a hydraulic pump, meaning each step of the process had to happen sequentially.

Performance is ferocious, the 4.0-litre twin-turbocharged V8 engine producing 765PS – giving the 765LT Spider a best-in-class power-to-weight ratio of 598PS-per-tonne at lightest dry weight – and 800Nm of torque. Transmission gear ratios have been revised for even greater engagement and performance; in-gear acceleration is 15% quicker than a 720S Spider, helping the new Longtail to achieve the fastest lap times ever posted by a convertible LT model.

The 0-100km/h time often seen as a benchmark figure is 2.8 seconds (0-60mph is 2.7 seconds), with 0-200km/h (124mph) taking 7.2 seconds. The new LT Spider takes 10.0 seconds to cover 400m (¼ mile) from standstill and the car’s maximum speed is 330km/h (205mph).

The most powerful McLaren convertible ever and the latest and most engaging addition to the brand’s Longtail lineage can be ordered now from McLaren retailers. Pricing is from £310, 500* and availability is limited to just 765 cars for customer order worldwide, with 2021 production already all sold.

In addition to all this, a significant proportion of the 80kg weight saving over the 720S is achieved inside the cockpit. The carbon fibre-shelled race seats fitted as standard are together 18kg lighter than the 720S sports seats. First seen on the McLaren P1™, the seats feature a lightweight Alcantara® covering, which also appears on the steering wheel, dashboard and doors.

The cockpit’s central tunnel is made of carbon fibre just 0.8mm thick, the door pockets are replaced by nets, and carbon fibre has been used for such micro-details as the window switch surrounds, steering wheel clasp and Active Dynamics Panel surround. Further weight is saved by deleting the floor carpet (saving 2.4kg), air-conditioning system (10kg) and audio system (1.5kg) – although the latter two can be specified for fitment at no extra cost.

The weight-saving measures incorporated as standard achieve the 80kg delta to the 720S, but for owners who want to go even further a lightest dry weight of just 1,278kg is possible by fitting optional components such as Super-Lightweight carbon fibre race seats. First developed for the McLaren Senna, these seats are one-third lighter than the standard seat, an innovative double-skin technology meaning each seat shell weighs just 3.35kg.

“As we continue to build the LT sub-brand with the introduction of the new 765LT Spider, it’s clear that our customers are increasingly attracted to the Longtail supercar proposition of exhilarating, extreme performance and limited availability. With all 765 examples of the 765LT coupe sold, it’s no surprise that as we publicly announce our new LT Spider, production capacity for 2021 is already filled.”

Mike Flewitt, Chief Executive Officer, McLaren Automotive

“A McLaren ‘Longtail’ is engineered to deliver not only incredible performance but also the highest levels of driver engagement. The 765LT coupe set new benchmarks in maximising a driver’s connection with the car and the Spider builds on this, adding the additional engagement factor of open-air driving to give direct access to the scintillating sound of the titanium exhaust – a pleasure that thanks to the electrically operated rear window can also be enjoyed with the retractable roof in place.”Jamie Corstorphine, Director of Product Strategy, McLaren Automotive

“Lowering the convertible roof of the 765LT Spider opens up another level of driver engagement. The coupe is impressive in its own right, but when you lower the roof of the Spider, there is a step-change in character – almost a theatrical element, like experiencing a live orchestra from right in front of the stage.” Ian Howshall, Global Product Manager, McLaren Automotive

“We’ve kept the weight delta between 765LT coupe and Spider to an absolute minimum. The exacting development of the RHT and the fact the chassis doesn’t need any stiffening ensure that the Spider is in every respect a true driver’s car – extremely track-focused and dynamically the equal of the coupe.”James Warner, Chief Engineer, McLaren Automotive

Key connectivity functions, including McLaren Track Telemetry (MTT), are displayed on the 8-inch, high-resolution Central Infotainment Screen, which works in conjunction with the innovative Folding Driver Display located directly in front of the driver to provide an integrated information platform. Primary functions, such as the Active Dynamics Panel, are located in the driver’s field of view.

Customers who value convenience features above relentless pursuit of weight saving can embrace a portfolio of choices. An audio system is absent from the standard specification – saving 1.5kg – but a lightweight McLaren 4-speaker system can be optioned at no cost, as can Bluetooth telephony, iPod/iPhone integration and audio voice prompts. An upgraded, world-class audio system developed specially for McLaren by Bowers & Wilkins, is also available.

Door stowage pockets and a central tunnel with lockable stowage can be specified as options in lieu of the lightweight nets and carbon fibre central tunnel fitted as standard. A driver-controlled vehicle-lift system that raises the nose of the car when needed to traverse speed bumps or car park ramps is a no-cost option, as is a choice of high-definition reversing camera or enhanced 360-degree 4-camera park assist system featuring ‘bird’s eye’ view. In applicable markets, Homelink® enables the remote opening of up to three electric garage doors or house gates.

The highly complex and completely bespoke design of the front splitter also plays a huge role in the 765LT’s performance. It separates, directs and works the airflow around, over and under the car, cooling the Low Temperature Radiators (LTRs) which sit behind the headlights. The outer edges of the splitter feature distinctive vertical blades which guide airflow around the front wheels and calm the aero wake, working in conjunction with the airflow coming out of the LTR exit vents above. Upturned aero blades sit between the inner surface of the vertical blades and the front bumper, acting as dive planes similar to those on the 720S GT3 race car and track-only McLaren Senna GTR, with air directed up and over them to create more downforce.

The doors of the Spider differ from those of the coupe in that they have no upper carbon fibre frame, are physically smaller and lighter and require only a single hinge (compared to the coupe’s double hinge fitment). When opened, the Spider’s doors extend further than the coupe’s by 120mm each side – the only difference in dimensions between the two models.

The doors employ the double-skin technique used in the legendary McLaren P1™ and further developed to great effect on the 720S. The door blades have been modified to integrate an additional vertical blade that extends from the skirt of the vehicle and controls turbulent air as it exits the front wheelarch, helping to guide it into the expanded intakes ahead of the rear wheelarch. These intakes feed the lower section of the High Temperature Radiators (HTRs), increasing the efficiency of the cooling system.

The nose of the 765LT Spider is 48mm longer than that of the 720S and the active rear wing adds 9mm, making the car 57mm longer overall. The front bumper and splitter – the latter now being closer to the ground because the ride height at the front is 5mm lower than that of a 720S – have been moved forward. Rear ride height remains the same, which increases vehicle rake and creates more downforce.

The 765LT may be longer than a 720S, but the bodywork has less physical volume overall, increasing heat evacuation from the engine bay and reducing air pressure within the wheelarches. At the rear, the bumper has been pushed closer to the engineering hard points, exposing the rear tyres, while above it the active rear wing overhangs and curves upwards towards its centre. The active rear wing is as imposing as it is effective: longer than a 720S wing, 60mm higher and with a 20% greater surface area, its elevated position increases downforce even at lower speeds when it isn’t deployed. Because the wing has a minimal effect on drag, the 765LT’s downforce-to-drag ratio (aero efficiency) is also increased over the 720S, again by 20%.

The elongated silhouette which gave the original Longtail its name back in 1997 was created for a very specific purpose, and everything McLaren has designed since then has followed that philosophy of ‘everything for a reason’ and ‘form follows function’. The 765LT Spider is the absolute example of this, with every detail of its highly complex, sculpted shape serving the cause of higher performance.

“Our mission is to transform cars that are already exclusive into something unique. McLaren Special Operations puts customers at the centre of the creative process, with access to a full range of personalisation choices – from the individual components, performance enhancements and finishes comprising the rich menu of MSO Defined options through to bespoke options and projects that produce one-of-a-kind cars. More than 85% of 765LT coupe customers have engaged with MSO and we are expecting interest from Spider buyers to be higher still.”Ansar Ali, Managing Director, McLaren Special Operations

“A McLaren LT is defined by its rebellious spirit, and a distinctive, striking appearance is an important part of that appeal. The dynamic attributes of a Longtail also demand physical changes; the stretched silhouette that enhances aerodynamic performance and the honed physique that improves downforce and cooling – especially on track – immediately signal that the 765LT Spider is a car that will deliver on the promise of the purest driving thrills.”Rob Melville, Design Director, McLaren Automotive

The unique LT soundtrack plays a much more complex part in driver engagement than simply filling the cabin with sound. Engine mount stiffness is increased to aid dynamic performance, and also to transfer and radiate more of the engine’s low-frequency sounds into the cabin, amplifying each change in rpm and allowing the driver to physically experience the engine.

The titanium exhaust system dominates the soundstage as much as it does the rear of the car. The four centrally mounted round exit pipes are meticulously designed, sized, angled and positioned, the pipe diameter increasing exhaust volume and the relative position of each pipe to the others delivering the precise harmonic content required. The resulting high-frequency note that rises with the rev range – a sound so key to the heart of the driving experience that it was established first on an early mule test, even before design and thermal management were addressed – is one of the LT ‘signatures’.

Power and torque delivery – 765PS (755bhp) at 7,500rpm and 800Nm (590lb ft) at 5,500rpm – are controlled by an engine management system with bespoke calibration. The benchmark acceleration figures tell their own story: 0-100km/h (0-62mph) in 2.8 seconds (0-60mph in 2.7 seconds), and 0-200km/h (0-124mph) in 7.2 seconds. This extraordinary performance – comparable with that of the coupe – is made even more accessible by gear ratios optimised to deliver acceleration times 15% quicker than those achieved by the 720S, with virtually instant throttle response throughout.

Steering feedback is enhanced by a quicker steering rack ratio and stiffer torsion bar being added to McLaren’s lauded electro-hydraulic steering system. The linked-hydraulic Proactive Control II suspension introduced on 720S benefits from 765LT-specific updates to software – which features revised algorithms derived from those developed for the McLaren Senna and Speedtail programmes – and hardware changes including the new lightweight dual springs. At the front, ride height is 5mm lower and track 6mm wider than on a 720S. All of these measures optimise precision, control, stability and roll stiffness to deliver an even more track-focused driving experience.

That intuitive connection between driver and car is a core strength of all McLarens, but in an LT model it is elevated to new heights. Every element of the 765LT driving experience is enhanced in both Spider and coupe, the two models having been developed alongside each other with the clear strategy of delivering an equally visceral level of engagement.

“We developed the 765LT Spider to be a car without compromise, every bit as exciting and rewarding to drive as the coupe, with all of the connection, closeness and engagement – but with the added benefit of so much more of that amazing LT sound, even closer to the driver. “James Warner, Chief Engineer, McLaren Automotive

The 765LT’s bespoke brakes, wheels and tyres are also key to enhanced dynamic feedback and driver engagement. Braking performance is simply phenomenal, latest-generation carbon ceramic discs combining with calipers from the McLaren Senna to provide precise pedal feel and astonishing stopping power. The 765LT Spider also features the Formula 1-inspired integrated caliper cooling that debuted on the coupe, reducing brake pad temperatures by up to 50 degrees during track driving and ensuring consistent feel and performance.