Guide: From Inline 6 to Monster V8 - a Historical & Technical Appraisal of the Mercedes-Benz C 43 AMG
BACKGROUND
Having begun to collaborate with an official DTM racing programme in 1989, Mercedes-Benz and AMG forged ever closer ties during the years that followed.
In 1990, the two firms signed a contract that saw Mercedes begin to cooperate with AMG on the development of high performance models. Included was an agreement that also enabled AMG vehicles to be sold and maintained through Mercedes’ worldwide dealer network.
Then, at the Frankfurt Motor Show in September 1993, the first model developed jointly by Mercedes and AMG at the pre-production stage was unveiled: the C 36 AMG.
Based on Mercedes’ entry-level W202 C-class Saloon launched just three months earlier, the C 36 featured a straight six engine that had been enlarged from 2.8 to 3.6-litres and further equipped with all manner of high performance equipment during its hand-built assembly process at AMG’ Affalterbach headquarters. There was also a special four-speed automatic gearbox with heavy-duty differential plus stiffer suspension, a lower ride height, uprated brakes, quicker steering and a set of big new AMG alloy wheels.
With its sporty new look, the C 36 served as a more refined alternative to BMW’s E36 M3, but unlike its Munich rival, the hot new Mercedes could only be configured as a four-door Saloon whereas the M3 could be ordered in one of three body styles (Saloon, Coupe or Cabriolet).
Taking a leaf from BMW’s book, when Mercedes launched a replacement for the C 36 at the Frankfurt Motor Show in September 1997, a second body style was offered to broaden the model’s appeal.
The resultant C 43 AMG was thus available as both a four-door Saloon (W202) and a five-door Estate (S202). Under the hood was a completely different engine, something better able to rival the improved 3.2-litre 321bhp M3 Evolution that BMW had replaced the original 286bhp three-litre variant with during the autumn of 1995.
In addition to its new V8 engine, stopping capability was improved thanks to the installation of a brake system imported from the recently introduced W210 E 55 AMG.
Meanwhile, the C 43 became the first AMG product to be assembled at Mercedes-Benz. Although the engines themselves were still prepared in Affalterbach, the rest of the assembly process took place in-house at Bremen. By contrast, Mercedes had previously sent partially assembled C 280 Sports from their factory in Bremen to the AMG facility 600km south where each car was stripped of its surplus equipment and brought up to C 36 trim.
ENGINE / TRANSMISSION
Undoubtedly the biggest difference in the transition from C 36 to C 43 was the switch from an iron block straight six to an all-alloy V8.
The 4.3-litre 90° V8 in question was based on the unit found in Mercedes’ W210 class E 430, production of which had got underway in August 1997.
These Type M113 E 43 units ran a single overhead camshaft per bank, three valves per cylinder (two intake, one exhaust), twin spark ignition, wet-sump lubrication and sequential fuel-injection. Other equipment included an aluminium oil pan and pistons, iron-coated piston skirts, hollow forged steel connecting rods, single-piece cast camshafts and a magnesium intake manifold. The block itself was fashioned from Alusil (an aluminium-silicon alloy).
Displacement was 4266cc thanks to a bore and stroke of 89.9mm and 84mm respectively.
With a compression ratio of 10.0:1, peak output was 275bhp at 5750rpm and 295lb-ft at 3000 to 4400rpm.
Unlike the standard 4.3-litre V8 built in Unterturkheim, the AMG versions assembled in Affalterbach came with an array of upgrades to increase output, particularly at higher engine speeds. These included stiffer valve springs, modular instead of cast camshafts with modified timing (to provide additional overlap), a shaved and polished crankshaft, a higher pressure oil pump, oil jets to cool the bottoms of the pistons, bigger fuel injectors, a new free-flow twin-tube air-cleaner and a ported magnesium intake manifold. The ECU was also re-mapped.
The net result was an additional 27bhp and 7lb-ft with 302bhp at 5850rpm and 302lb-ft at 3250rpm.
As per last-of-the-line examples of the outgoing C 36, the C 43 came with a five-speed automatic gearbox imported from the contemporary SL 500 and then modified to achieve improved up-shifts at high engine speeds. Transmission was through a single-plate clutch and heavy duty open differential. An ASR traction control system (switchable via a button on the centre console) was fitted as standard.
CHASSIS
As the C 43 was the only C-class to use a V8 engine, its galvanised steel monocoque bodyshell was uniquely modified to accommodate said engine. The W202 Saloon came with an enlarged 69-litre fuel tank under the trunk floor while the S202 Estate retained a 62-litre item.
Suspension was via double wishbones up front and a multi-link arrangement at the back with coil sprung dampers all round and an anti-roll bar at either end.
Compared to a Sport-equipped C-class, these AMG variants featured stiffer gas-filled degressive shocks, a slightly lower ride height and thicker anti-roll bars.
Instead of the vented 320mm front and 278mm solid discs fitted to the C 36, the C 43 came with the same all-vented brake system used by the bigger W210-based E 55 AMG. Accordingly, the fronts were enlarged to 334mm, those at the rear were 300mm, and twin-piston floating calipers were used on both axles.
Wheels were the same 17-inch AMG Monoblock 2 rims as used on the ‘97 model year C 36. These measured 7.5-inches wide at the front, 8.5-inches wide at the rear and were shod with Michelin Pilot SX tyres (225/45 ZR17 and 245/40 ZR17 respectively).
BODYWORK
Externally, aside from a new C 43 badge on the trunk lid / tailgate, the C 43 was identical to the handful of very late C 36 cars that featured more sculpted bumpers and crossover side skirts in addition to the new door trim mouldings, smoked tail light clusters and rear windscreen with integrated radio antenna that had been introduced for the 1997 model year.
The bumpers and skirts (fashioned from Xenoy resin) were designed to reduce high speed lift and give a more purposeful stance. Cooling had also been an important consideration at the front of the car where enlarged intakes were joined by a more effective spoiler.
The overall effect of the updated bumpers and skirts was to give a more modern, more curvaceous look than the slightly fussier, harder edged original.
As per the C 36, down each flank was faux exposed carbonfibre B-pillar trim (instead of black plastic).
Aside from the bumpers, sills, door trim mouldings and mirrors housings, steel body panels were used throughout.
INTERIOR
For the C 43, Mercedes ditched some of the equipment that had been fitted to the C 36 such as the gaudy duo-tone steering wheel, the matching bi-colour gear knob and the light grey instrument fascia. These were replaced with mono-tone items and a satin black fascia respectively.
Instead of Sport Check velour fabric, leather upholstery was now fitted as standard and white-faced gauges replaced the original black-faced items.
Housed behind the leather-trimmed four-spoke steering wheel was an AMG-branded 280kmh / 160mph speedometer. Off to the right was a slighly smaller 7000rpm rev counter and to the right a combined read out for water temperature and fuel (both of which were imported from the regular W 202).
As per the C 280 Sport and outgoing C 36, the C 43 came with Sports seats and faux exposed carbonfibre trim for the central console.
OPTIONS
The list of optional extras available on the C 43 included a rear spoiler for the Saloon, rear sports seats, two-tone upholstery (seats, door panels, steering wheel and gear knob), heated front seats, wood trim inserts, an electric sunroof, an uprated audio system with CD changer, an in-car telephone, an adjustable steering column, headlight wash / wipe, a split-folding rear seat (Saloon only), rear parking sensors and an alarm / immobiliser.
In addition, all manner of personalisation could be carried out at the AMG facility (albeit at not inconsiderable cost). AMG are known to have fitted certain cars with bigger three-piece split-rim wheels and rolled fenders, extended leather (to include a leather headliner), Birch wood trim, perforated leather steering wheels with contrast stitching and full chrome delete.
WEIGHT / PERFORMANCE
Although the C 43’s aluminium V8 was actually lighter and more compact than the iron-block straight six found in the C 36, these latest variants tipped the scales 10kg heavier overall as a result of the beefed up bodyshell and leather upholstery that was now fitted as standard.
The C 43 Saloon came in at 1570kg (up from 1560kg) while the Estate variant tipped the scales at an additional 50kg (1610kg).
Top speed was once again electronically limited to 155mph. In de-restricted form, 168mph was possible (up from 162mph).
The 0-62mph time dropped from 6 to 5.7 seconds for the C 43 Saloon while the Estate was one-tenth slower (5.8).
C 55 AMG CONVERSION
In July 1998, Mercedes began to offer customers a C 55 conversion for their C 43. This essentially involved installation of the 5.4-litre Type M 113 E 55 engine from the recently introduced W210-based E 55 AMG plus a brand new gearbox and differential (taken from the W208 CLK 55 AMG). The conversion also included a higher final drive ratio (2.82:1 instead of 3.07:1). a modified exhaust and a 300kmh / 180mph speedometer. Significantly, the C 43’s floorpan under the rear seats had to be modified to accommodate a beefier rear axle.
These 5.4-litre motors came with a bigger bore and longer stroke (up from 89.9mm and 84mm to 97mm and 92mm respectively) for an additional 1173cc (up from 4266cc to 5439cc). They also ran a higher compression ratio (up from 10.0:1 to 10.5:1).
Peak output was 342bhp at 5500rpm and 376lb-ft at 3500rpm to 4300rpm.
This represented gains of 40bhp and 74lb-ft over the C 43 motor which pumped out 302bhp at 5850rpm and 302lb-ft at 3250rpm.
The 0-62mph time was cut from 5.7 to 5.5 seconds (Saloon) and 5.8 to 5.6 seconds (Estate).
Top speed was again electronically limited to 155mph, but in de-restricted form 175mph was attainable.
Owing to the C 55’s very expensive price (which added around 60% to the cost of a standard C 43), just 59 examples were built. Of these, 52 were Saloons and seven were Estates. Some of the Estates were retained by Mercedes to serve as F1 Safety Cars during the 1998 and 1999 Formula 1 seasons.
PRODUCTION CHANGES
For the 2000 model year, the C 43’s gearbox software was re-mapped to give better performance and longer life. At the same time, gear shifts could now be executed via Tiptronic-style buttons and AMG-branded brake calipers were added along with electric steering wheel adjustment.
END OF PRODUCTION
C 43 production was ran from September 1997 until July 2000 in the case of the S202 Estate and from October 1997 until May 2000 in the case of the W202 Saloon.
In total, 3857 examples were produced, 3085 of which were Saloons and 772 Estates.
A replacement based on the second generation W203 C class (the supercharged V6-powered C 32 AMG) was launched at the Detroit Motor Show in January 2001.
Text copyright: Supercar Nostalgia
Photo copyright: Mercedes-Benz - https://www.mercedes-benz.com
