BMW Z4 (E85)

BMW Z4 (E85 & E86)
Overview
Manufacturer	BMW
Production	September 1, 2002 – August 28, 2008 (Roadster)
Assembly	Greer, Spartanburg County, South Carolina, United States (BMW US Mfg. Co.)
Designer	Anders Warming (1999)
Body and chassis
Class	Compact luxury sports car (S)
Body style	2-door roadster 2-door coupé
Layout	FMR layout
Powertrain
Engine	2.0 L N46B20 I4 2.2 L M54B22 I6 2.5 L M54B25 I6 3.0 L M54B30 I6 3.0 L N52B30 I6 3.2 L S54B32 I6
Transmission	5/6-speed manual 5/6-speed automatic
Dimensions
Wheelbase	2,495 mm (98.2 in)
Length	4,090 mm (161.0 in)
Width	1,780 mm (70.1 in)
Height	1,300 mm (51.2 in) (roadster) 1,285 mm (50.6 in) (coupe)
Chronology
Predecessor	BMW Z3
Successor	BMW Z4 (E89)

The first generation of the BMW Z4 was designed by Danish BMW-designer Anders Warming from mid-1998 to March 1, 2000.^[1] The Z4 was introduced at the Paris Auto Show in 2002, and went on sale in November of the same year for the 2003 model year. It is a physically larger, completely redesigned successor to the Z3. Initially, it was only available as a roadster with the 2.5L or 3.0L inline six-cylinder engines. Warming's design was controversial, as were many BMW designs of the time produced under the watchful eyes of BMW chief designer Chris Bangle.

The Z4's design addressed many criticisms of the preceding Z3; the Z4 is larger, and has a significantly stiffer chassis. The Z4 features a strut type front suspension like its predecessor. The rear suspension, however is considerably different from that of the Z3, which was based on that of the E30 BMW 3 Series. Instead of a semi-trailing arm suspension, the Z4 uses a more advanced multi-link suspension.

Features

The Z4 used lightweight materials to offset the increased weight over the smaller Z3, such as aluminum hood and suspension components, magnesium roof frame. Run flat tires removed the need for a spare tire, which in addition to saving weight, allowed for a larger boot.

Advanced aerodynamics yield a drag coefficient of 0.35 and a relatively calm passenger compartment when the top is down.

The 6-cylinder engines included all-alloy construction, double VANOS variable valve timing and streamlined intake and exhaust manifolds, throttle by wire. Safety technology included four-wheel disc brakes and electronic stability control, incorporating ABS and traction control. The electric power steering was speed-sensitive, allowing for easier manoeuvering at low speeds.

A "Sport Package" added stiffer and lower suspension, larger wheels, and sport tuned electronic steering, throttle and shift parameters.

The SMG transmission was offered in addition to the more usual manual and automatic transmissions.

Production of a cheaper 2.2-litre model began in October 2003, priced from £18,500 in the UK. It weighs 35 kg (77 lb) less than the 3.0L version, but is still heavier than the 2.5L Z3's weight of 1,315 kg (2,899 lb). A 2.0L 4-cylinder engine for the European market was introduced in May 2005.

Z4 Coupé (E86)

2007 Z4 3.0si Coupe (US)

BMW unveiled a concept coupé version of the Z4 at the Frankfurt Motor Show in 2005. The design of the Z4 and Z4 coupé has variously been ascribed to Anders Warming, Chris Bangle, the controversial former BMW Head Designer, and Adrian van Hooydonk, current BMW design chief,^[2][3] and BMW designer Tomasz Sycha. The company announced in 2005 that the coupé would be available for production including the return of the M Coupé. The production cars were introduced at the New York Auto Show in April 2006.

The M Coupé shares its award winning S54B32 3.2 L Inline-6 with the M Roadster. The S54 won the International Engine of the Year award overall for 2001, and also claimed the “Best New Engine” that year as well as won the 3–4 L category for six straight years in a row from 2001 through 2006. The S54 was also on the Ward’s 10 Best Engines list for 2001 through 2004.^[4]

Thanks to its hatch design, the Z4 Coupé offers 10.1 cu ft (0.29 m³) of trunk space,^[5] as opposed to 8.5 cu ft (0.24 m³) for the roadster.^[6]

Z4 coupe (Europe)

The E86 Coupé features a fixed hard-top roof which yields additional torsional rigidity—32,000 N·m (24,000 lb·ft) per degree of body twist on the coupe compared to 14,500 N·m (10,700 lb·ft) per degree on the roadster. This additional rigidity improves driving dynamics and corner handling.^[7] The roof now features a 'double bubble' contour which serves as an aerodynamic aid and offers more headroom than the roadster with top closed. The Coupé has a sleek fastback rear window that slopes down to an integrated spoiler shaped to deliver downforce to the rear axle at speed.

Besides the M-version, the Coupé (and the roadster) were also available as the 255 horsepower 24-valve DOHC 3.0si, with BMW's familiar N52 inline-six, of 2996cc displacement. This is from the same engine family as that found in the 3-series sedan, with its novel magnesium-and-aluminum hybrid block casting. The engine makes incredibly smooth power through a slick-shifting six-speed manual or an optional "Steptronic" six-speed automatic ^[8] featuring Adaptive Transmission Control and steering-wheel-mounted manual shift paddles.

Production:
Over the Z4 E86 life cycle (2006–2008), only 12,819 Z4 coupés (E86) were produced worldwide, as well as 4,275 Z4M coupés,^[9] yielding a total of 17,094 coupés (Z4 and Z4M).^[10] The last Z4 car was made on 28 August 2008 with 197,950 total vehicles produced over the Z4's five-year lifecycle. Bobby Hit, a spokesman for BMW's US manufacturing operations, states that 180,856 vehicles were roadsters and 17,094 were coupés. Of the 17,094 coupés manufactured worldwide, only 3,919 were made for the North American (NA) market (NA=US and Canada) of which 1,815 were the M-Coupe and 2,104 were the 3.0si Coupe. Of the 2,104 3.0si Coupes made, 1,276 were automatics and only 828 were manual transmission (the Z4M however, was only available as a manual transmission everywhere). Therefore, less than 1/3 of all Z4 coupés made for NA (M and non-M 3.0si) were automatics.^[11] Even from its introduction in 2006, the Coupé was relatively rare: In its first 13 months on the market, the roadster outsold it at a ratio of 7 to 1.^[12]

Production numbers for the 2,104 NA version of the E86 3.0si Coupé were: 2006 = 348; 2007 = 1,280; 2008 = 476.

Production numbers for the 1,815 NA version of the Z4M 3.2L Coupé were: 2006 = 380; 2007 = 1,187; 2008 = 248.

BMW Concept Coupé Mille Miglia 2006

BMW Concept Coupé Mille Miglia 2006, BMW Museum, Munchen, Germany.

It is a concept car inspired by the BMW 328 Mille Miglia Touring Coupé, but uses the Z4 M Coupé's drive components. The concept car is 23 cm longer, 14 cm wider, and 4 cm flatter than the Z4 M Coupé. Other features of the concept car include 20-inch alloy wheels with 245/40R20 tires, permanently integrated sidewalls, swing-up cockpit, LED headlight panel, silver-coloured carbon-fibre reinforced plastic body, 3-material (stainless steel, untreated cowhides and Lycra fabric) interior.^[13]

The vehicle was designed by Anders Warming.^[14]

2006 update

2006–2008 BMW Z4 3.0si

In 2006, BMW updated the Z4 line by introducing the M Roadster, and later the M Coupe, with the vaunted S54 "M" engine. The standard cars received the new N52 I6 engines. The N52 features a magnesium block construction, which consists of an aluminium interior for the cylinders, and an outer magnesium block. The engine features BMW's Valvetronic variable valve timing system for increased performance, are considerably more powerful through the middle of the rev range, and also improve fuel economy noticeably. A final benefit of the N52 engines is that they improve handling and turn-in due to the decreased weight over the nose of the car. This is particularly noticeable when compared to the Z4 M, which continued with the heavier S54 iron block engine.

Standard equipment included Run Flat tires, ABS Brakes, Stability Control, Traction Control, CD Player, Power Locks, Power Windows and Air Conditioning. The Z4 included Side Airbags, Driver Airbags, Passenger AirBags, Knee Airbags and 5 Star Rollover Protection.

In addition to the powertrain updates, BMW made mild revisions to the styling of the Z4, added several electronic features, and increased the brake size on the 3.0si models.

The 2006 BMW Z4 received a number of updates including a revised exterior, more powerful engines and improved interior features. Highlighted by a new front bumper ensemble with a larger air intake, rectangular foglights and front side reflectors, the exterior also received new wheels, rear bumper and taillight designs. The interior was fitted with a new aluminium trim, shift knob for automatic transmission and new colors. The 3.0i replaced the 2.5i and the 3.0si replaced the 3.0i. Power for the 3.0i was 218 bhp while the 3.0si got 261 hp (195 kW) and 232 lb·ft (315 N·m) of torque. A 6-speed manual transmission was standard with an optional 6-speed automatic. 17-inch wheels were standard on both trims and the Sport Package also features new wheels as well.

Criticisms

• Electro-mechanical power assist steering. The Z4 includes an electro-mechanical power assist steering system which earned the vehicle considerable criticism. The system was introduced as a fuel-saving device by removing hydraulic pump loads from the engine. BMW claims this system provides a "more dynamic drive" and a "more direct feel." Motor journalists^[15][16] and racing drivers complained, however, that this device gave the vehicle an artificial, synthetic or indirect steering feel. The BMW Z4 M on the other hand, only included conventional hydraulic assistance, said to have given the car a much more direct and communicative feel.^[17]
• Some motorsports journalists have on a couple of occasions complained on the harsh ride of a car they otherwise favor. The harsh ride of the vehicle is possibly explained by a change in rear toe angle when the Z4's rear suspension moves up and down, meaning it would begin to 'steer' from the rear on undulations found on less than track condition roads.^[18]

Specifications

E85 & E86 Variants

All models are E85 roadsters except as noted. European specifications shown. North American vehicles have slightly lower power ratings, due to lower compression ratios necessitated by fuel quality issues.

• The 2.0i was only sold in Europe. The 3.0i Roadster was sold in Germany until 2005.

• US models include 2.5i ('03–'05), 3.0i Roadster, 3.0si Roadster & Coupé, M Roadster & Coupé.^[20]

Engines

Power and torque figures will vary slightly between North American and European specification engines.

The Z4 M shares the same engine as the E46 BMW M3, but due to gearing differences, is marginally slower than the M3. The North American version is 3 horsepower shy of the M3's 333 horsepower. However this is better than the Z3 version, which, while using the same engine, was all the way down to 315 horsepower. 0–60 mp/h takes 5.0 seconds, and the top speed is limited to 250kph or 155 mph.

Motorsports

Dieter Quester, Dirk Werner, Jamie Campell-Walter and Tim Mullen won the Silverstone Britcar 24 Hour Race with a BMW Z4 M Coupé.^[22] The unit of the racing version is a modified and reinforced version of the S54B32 3.2-litre engine, delivering around 294 kW/400 hp. The car is made by BMW's M Division and called the Z4 M Coupé Motorsport.^[23] The Z4 Coupe Motorsport version weighs 1,200 kg/2,643 lb with a driver and has a 120-litre/30-gallon fuel tank for endurance racing. The racing kit for the Z4 M Coupé is available for € 250,000, plus VAT (US $391, 025) (UK £233, 500) in addition to the list price of the car. The Racing Kit is very popular among Group N drivers, which also got a lot of good results in the track.

In August 2008, a modified Z4 debuted in Round 6 of the Super GT season, participating in the GT300 class. It is powered by a detuned version of the S62 V8 engine from the E39-Series M5. Although it is well known by fans since it has a unique image (or called "Itasha"), this car also marked the return of BMW to Super GT series since their exit from the previous JGTC (which they used the M3). They continue to participate in the 2009 Super GT season other than Sepang Race,^[24] and they would replace their H-pattern to a sequential transmission, as well as their S62 Engine with an S65B40 after race 3, after they had suffered an unrepairable engine blow in race 2 at Suzuka.^[25] The car served them for 2008 and 2009 season, and their team used the BMW Z4 GT3 in 2011 season instead, which helps them becomes the GT300 Champion that season.

In the 2008 Super Taikyu Endurance Series (equivalent to Group N championship) in Japan, both BMW Z4M's entered by Petronas Syntium Team won the Super Taikyu 1 class first and second taking both the championship and drivers title. Both cars dominated the series by taking first and second at every race in the 2008 season beating cars like Porsche GT3 (both 996 and 997), Honda NSX, Mitsubishi Evolution X, Mazda RX-7, Nissan GTR and Nissan 350Z. The Super Taikyu endurance races usually last for at least 500 kilometers or 4 hours highlighted by the race of the season, the 24 Hours of Tokachi. In total Petronas Syntium Team gathered 277 points compared to the second place team Endless Sports with a mere 98 points.^[26] The cars were driven by established and popular drivers such as Nobuteru Taniguchi, Masataka Yanagida, Manabu Orido and father and son pairing of Hans-Joachim Stuck and Johannes Stuck.^[27]

The team of Bas Leinders secured pole position at the 2011 24 Hours of Spa in their Z4.^[28] This team did not finish, however the Z4 of Dirk Werner came 2nd in the race.

Production

The M coupe's production began at the Spartanburg BMW plant in Greer on 4 April 2006.

The last of the first-generation Z4 (Z4 3.0si Roadster in Space Grey) rolled off the production line on 28 August 2008.^[29]

Over the Z4's life cycle, 197,950 vehicles had been produced, with 180,856 roadsters and 17,094 coupés.^[10]

References