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McLaren 675LT
Overview
Manufacturer	McLaren Automotive
Production	2015–present
Designer	Frank Stephenson
Body and chassis
Body style	2-door coupé
Layout	RMR layout
Powertrain
Engine	3.8 L twin-turbo M838T V8
Transmission	7-speed dual-clutch
Dimensions
Wheelbase	2,670 mm (105.1 in)
Length	4,512 mm (177.6 in)
Width	2,093 mm (82.4 in)
Height	1,203 mm (47.4 in)
Kerb weight	2,993 lb (1,358 kg)

The McLaren 675LT (where "LT" stands for Long Tail) is a lightweight, track-focused evolution of the McLaren 650S.

It was announced in February 2015 and introduced at the Geneva Motor Show 2015. It is currently the fastest car on the Top Gear test track with a time of 1.13.7 beating the Pagani Huayra by just .1 of a second.

Chassis

As with the 650S, the 675LT makes use of single-piece carbon fibre monocell weighing 75 kg (165 lb), and carbon fibre use in the vehicle is increased in order to further minimise weight and increase rigidity. The 675LT is supplied with new carbon ceramic brake discs to increase braking performance over the 650S. Disc sizes are 394 mm at the front and 380 mm at the rear. Six-piston calipers grip the front discs with four-piston caliper used for the rears. Braking performance is also aided by the air brake ability of the new rear wing.

The 675LT makes use of a new 10-spoke wheel design, each weighing 800 g less than the alloy wheels on the McLaren P1, supplied in a 19-inch front and 20-inch rear fitment.

The new wheels are shod in Pirelli P-Zero Trofeo R track-focused, street-legal tyres which increase grip by up to 6% over the P-Zero Corsa sold with the 650S.

Body and cabin

The 675LT utilises a new rear wing/air brake assembly 50% larger than that used in the 650S, along with a new carbon fibre diffuser and an 80% larger front splitter with sizeable endplates that together increase total downforce by 40%.

New carbon fibre pieces include both the front and rear bumpers as well as front undertray, rear fenders, side intakes and decklid that contribute to the significant weight savings over the 650S. Alcantara is used throughout the interior where carpeting is removed and removal of the air conditioning unit and new carbon fibre race seats together save 26.5 kg (58 lb). 1 millimetre thinner window glass further reduces weight by 3 kg (7 lb). This extreme focus in weight saving results in a dry weight of 1,230 kg (2,712 lb), some 100 kg (220 lb) less than the 650S.

Drivetrain

The car is powered by a variation of the M838T 3,799cc twin-turbo V8 petrol engine, producing 675 PS (496 kW; 666 hp) at 7100 rpm and 700 N·m (520 lbf·ft) at 5500 rpm. This is achieved through the addition of new lightweight connecting rods, bespoke camshaft, an electronic recirculation valve and a lightweight titanium exhaust. Also used in the engine are revised turbocharger compressor wheels and an optimised fuel pump.

The 675LT uses the seven-speed automatic dual-clutch gearbox used in the 650S, with improved software reducing the shift time.

Performance

The 675LT can accelerate from 0–100 km/h (62 mph) in 2.9 seconds, 0.1 seconds faster than the 650S. 0–200 km/h (124 mph) in 7.9 seconds, 0–300 km/h (186 mph) in 25.9 seconds, 0–322 km/h (200 mph) in 31.2 seconds, and do the 0-402m sprint (1/4-mile) in 10.3 seconds at 227.1 km/h (141.1 mph), continuing on to a claimed top speed of 330 km/h (205 mph). On episode 2 of season 23 of Top Gear, the 675LT became the fastest production car on the Top Gear test track with a time of 1:13.7, beating the Pagani Huayra's time of 1:13.8.

McLaren 675LT has a power to weight ratio of 1.82 kg (4.01 lb) per horsepower.

Nomenclature

The '675' in the 675LT model name refers to the power output of 675 PS, following the naming scheme started by the McLaren 650S. The LT in the model name is a reference to the "Long Tail" 1997 McLaren F1 GT which was the final incarnation of the F1 road car built to comply with FIA homologation regulations for the 1997 F1 GTR. The F1 GT featured extended front and rear overhangs that produced similar downforce to the previous homologation special, the F1 LM, without the use of a drag-inducing fixed rear wing.

675LT Spider (2016-)

McLaren 675LT Spider
Overview
Manufacturer	McLaren Automotive
Production	2017–present
Designer	Frank Stephenson
Body and chassis
Body style	2-door convertible
Layout	RMR layout
Powertrain
Engine	3.8 L twin-turbo M838T V8
Transmission	7-speed dual-clutch
Dimensions
Wheelbase	2,670 mm (105.1 in)
Length	4,512 mm (177.6 in)
Width	2,093 mm (82.4 in)
Height	1,203 mm (47.4 in)
Kerb weight	2,993 lb (1,358 kg)

A convertible variant of the 675LT was revealed online in December 2015. It shares the same 675 PS (496 kW; 666 bhp), 3.8-litre twin-turbocharged V8 engine as the coupé, but has a folding hardtop roof as seen on the 650S Spider. The 675LT Spider can accelerate from 0–100 km/h (0-62 mph) in 2.9 seconds and 0–200 km/h (0-124 mph) in 8.1 seconds. The top speed is reduced slightly, to 327 km/h (203 mph).

Motorsports

GT3

In June 2014, McLaren announced that they would produce a GT3 version of the 650S, either as a new car or as an upgrade for the existing 12C GT3 – which will contest GT3 championships from 2015 onwards.

Changes to the car from the road car includes a new 6-speed sequential motorsport gearbox; 380 mm ventilated brake discs with six-piston calipers at the front and four-piston units at the rear; a 52 mm wider track; revised suspension geometry and upgraded components. It is distinguished from the road car by larger air intakes and front splitter, and carbon fibre air intakes and a new rear wing.

The 3.8-litre McLaren V8 twin-turbo engine, also used in the 12C-GT3, produces 493 bhp (368 kW; 500 PS), and includes a new ECU to improve turbo boost and gearshifts. The power output is lower than the road going 650S’s due to homologation.

Andrew Kirkaldy, whose CRS Racing team developed the GT3 version of the McLaren MP4-12C, said that they were aiming to develop a version that conforms to the LM GTE regulations at the 2016 24 Hours of Le Mans.

The 650S achieved its biggest success when it won the 2016 Liqui Moly Bathurst 12 Hour race in Australia at the hands of Álvaro Parente, Shane van Gisbergen and Jonathon Webb. Van Gisbergen set a new outright lap record with a time of 2:01.567 on 7 February 2016.