Cars!

190E (2.3-16 &) 2.5-16 "Cosworth"

Back in the late 1970s, Mercedes competed in rallying with the big V8-powered Coupés of the R107 Series, mainly the light-weight Mercedes 450 SLC 5.0. Mercedes wished to take the 190 E rallying, and asked British race car engineering company Cosworth to develop an engine with 320 bhp (239 kW) for the rally car. This project was known as project "WAA" by Cosworth"[4]. During this time, the Audi Quattro with its all wheel drive and turbocharger was launched, making the 2.3-16v appear over-matched. With a continued desire to compete in high-profile motor sport with the 190, and also now an engine to do it with, Mercedes turned to the Deutsche Tourenwagen Meisterschaft (DTM) (German Touring Car Championship) motor sport series instead. Cars racing in this championship, however, had to be based on a roadgoing model. Mercedes therefore had to put into series production a 190 fitted with a detuned version of the Cosworth engine. This high performance model was known as the 190 E 2.3-16, and debuted at the Frankfurt Auto Show in September 1983, after its reputation had already been established. Three cars, only slightly cosmetically altered, had set three world records in August at the Nardo testing facility in Italy, recording a combined average speed of 154.06 mph (247.94 km/h) over the 50,000 km endurance test, and establishing twelve international endurance records.

Engine

The Cosworth engine was based on the 2.3-liter 8-valve 136 hp (101 kW) unit already fitted to the 190- and E-Class series. Cosworth developed the cylinder head, "applying knowledge we've learnt from the DFV and BDA". It was made from light alloy using Coscast's unique casting process and brought with it dual overhead camshafts and four valves per cylinder, meaning 16 valves total which were developed to be the "largest that could practically be fitted into the combustion chamber".

In roadgoing trim, the 190 E 2.3-16 produced 49 hp (36 kW) and 41 ft·lbf (55 N·m) of torque more than the basic single overhead cam 2.3 I4 engine on which it was based. The 2.3 L 16 valve engine made "185 hp (137 kW) at 6,200 rpm and 174 ft·lbf (235 N·m) at 4,500 rpm, the oversquare 95.50 x 80.25 mm bore and stroke dimensions ensuring that it revs easily up to the 7000 rpm redline"[6]. Acceleration from 0–100 km/h (62 mph) was less than eight seconds, and the top speed was 230 km/h (143 mph)[6].

US-Specification cars had a slightly reduced compression ratio (9.7:1 instead of 10.5:1), and were rated at 167 hp (125 kW) @ 5800 rpm and 162 lb·ft (220 N·m) @ 4750.

The roadgoing version of the engine was reconfigured with reduced inlet and exhaust port sizes, different camshaft profiles, no dry sump configuration and Bosch K-jetronic replacing the specialised Kugelfischer fuel injection. These changes helped bring power down to the required 185 bhp (138 kW) specification, but still resulted in a "remarkably flexible engine, with a very flat torque curve and a wide power band"[5]. The heads for the engines were cast at Cosworth's Coscast foundry in Worcester and sent to Germany to be fitted to the rest of the engine, parts of which were different from the standard 2.3 including light pressed alloy pistons, and rings designed to withstand higher engine speeds, whilst con-rods, bearings and bearing caps were found to be strong enough as standard and left unaltered[5].
[edit] 2.5 model

An enlarged 2.5 L engine replaced the 2.3 L in 1988. It offered double valve timing chains to fix the easily snapping single chains on early 2.3 engines, and increased output by 17 hp (12.5 kW) with a slight increase in torque. For the European market without catalyst (RÜF) the car delivered 204 bhp (150 kW). Catalyst equipped 2.5-16s produced a slightly reduced 197 bhp (147 kW). It is debated whether the 2.5 L engine was developed and built by Mercedes or Cosworth. Mercedes was not keen to broadcast the fact that their most sporting saloon car has an engine developed by a British company. However some cylinder heads from 2.5 L cars are stamped with the Coscast logo indicating they were cast at Cosworth's foundry just like the 2.3s. Cosworth also list the project code "WAB" for the development of the 2.5-16 valve head just as they do for the 2.3-16 valve head. Car program Top Gear predicted this 2.5 model to be one of the future classics in the car world, because of its relatively unknown history and rivalry with the BMW M3.

16v differences

Due to their performance, the 16 valve cars were different from the other 190 models. The body kit on the 2.3-16 and 2.5-16 reduced the drag coefficient to 0.32, one of the lowest CD values on a four door saloon of the time, whilst also reducing lift at speed. The steering ratio was quicker and the steering wheel smaller than that on other 190s, whilst the fuel tank was enlarged from 55 to 70 L. The Getrag 5-speed manual gearbox was unique to the 16 valve and featured a 'racing' gear pattern with 'dog-leg' first gear, left and down from neutral. This meant that the remaining 2nd, 3rd, 4th and 5th gears were in a simple H pattern allowing fast and easy selection. The gearchange quality was, however, noted as "notchy, baulky"[6], criticisms which weren't levelled at the BMW M3 (E30) which shared the same gearbox. The pattern is also unusual in that the driver engages reverse by shifting left and up from neutral, as for first gear in a conventional pattern. This was satirised in a Top Gear episode (S15E02) where James May took a 190E Cosworth and repeatedly pretended to confuse reverse and first gear. An oil cooler was fitted to ensure efficient oil cooling for the inevitable track use many of these cars were destined for.

The strictly four-seater interior had Recaro sports seats with strong side bolsters for front and rear passengers. 3 extra dials - an oil temperature gauge, stopwatch and voltmeter - were included in the centre console. The 190 E 2.3-16 was available in only two colours, Blue-Black metallic (Pearl Black in the US), and Smoke Silver. The 2.5-16 added Almandine Red and Astral Silver.

All 2.3-16 valve 190 models are fitted with a Limited Slip Differential (LSD) as standard. They were also available with Mercedes' ASD system which was standard equipment on the 2.5-16v. The ASD is an electronically controlled, hydraulically locking differential which activates automatically when required. The electronic control allows varied amounts of differential lock from the standard 15% right up to 100%. It is not a traction control system however, and can only maximize traction rather than prevent wheel spin. Activation of the ASD system is indicated by an illuminating amber triangle in the speedometer.

The suspension on 16 valve models is very different from the standard 190 (W201). As well as being lower and stiffer, it has quicker dampers, larger anti-roll bars, harder bushings and hydraulic Self-Levelling Suspension (SLS) on the rear. This allows the rear ride height to remain constant even when the car is fully loaded.

At the inauguration of the new, shorter Nürburgring in 1984, a race with identical cars was held, with former and current F1 pilots at the wheel. A rather unknown young driver named Ayrton Senna took First Place in that race.

Private Teams such as AMG later entered the 2.3-16 in touring cars races, especially the DTM. In the late 1980s, the 2.5-16 (never released in the United States) raced many times, against the similar BMW M3 and even the turbocharged Ford Sierra Cosworth.

Who wants high revs? For me just a lack of cylindrage and a waste of technical assetts... 

LOW revs & torque is my way for cars!

Rattler

If I see this last vid right, he does not even have leather seats?

         

TA

See? Q.E.D. !

TA

Q.E.D., from the Latin quod erat demonstrandum, used at the end of a definitive proof -snip-