BMW 320si – A real driver’s car

3-Series | October 28th, 2009 by 49
img0145tr 750x500 BMW 320si   A real drivers car

As our editor Andrew said in a previous article, the BMW 320si is a “hidden pearl”, a car known in the BMW community as a …

As our editor Andrew said in a previous article, the BMW 320si is a “hidden pearl”, a car known in the BMW community as a real driver’s car. Browsing Germancarzone today, came across a member of this forum, Nikos who has just taken ownership of a gorgeous 320si model.

Since the car was never available for the U.S. market, some of you might have overlooked it or simply never heard of it. No worries, we’re here to refresh your memory and …..to make you a bit jealous, just as we are at this moment.

In late 2005, when BMW announced its new E90 entrant for WTCC, BMW had to homologate the 320si by producing 2,600 road-going versions to compete. A lucky few in countries outside the U.S.(typical) were able to snatch up the low production series cars when they were first sold.

320si e90 front 655x483 BMW 320si   A real drivers car

While the 320Si is only a 2.0 liter, 4 cylinder engine, it produces 175 horsepower (275 horsepower in full race spec) and comes without Valvetronic as it limits the revving and performance capabilities of the engine. Even better, the engine was hand-built in the United Kingdom in the same BMW engine plant that also builds the engines for the BMW-Sauber Formula One program.

The 320Si came in sedan form and could only be purchased with a manual transmission. The sedan was decked out with the then-new M Sport body kit and custom 18 inch Style 216 wheels – straight off of it’s race car brethren. The major difference from the race-spec 320Si body and road-going version was the widebody kit front and back – and the racing livery along the sides!

For full details on the BMW 320si, we encourage all of you to read the press released issued years ago.

Special Model with the DNA of Motorsport: The BMW 320si Saloon
BMW now offers the customer with a particular penchant for motorsport a limited edition version of the 3 Series Saloon restricted to a total production volume of just 2,600 units: the BMW 320si. Featuring the M Sports Package and 18-inch wheels in the same design as the racing version, this special model boasts a fast-revving 2.0-litre four-cylinder power unit developing maximum output of 127 kW/173 bhp at 7000 rpm. This kind of power ensures a top speed of 225 km/h or 140 mph and acceleration to 100 km/h in just 8.1 seconds.

320si e90 wtcc front 655x483 BMW 320si   A real drivers car

Exclusivity in Limited Edition.
Over and above a sporting suspension set-up, the M Sports Package featured as standard on this special model comprises BMW’s Aerodynamics Package with modified bumpers and side-sills, sports seats, an M leather steering wheel, an M footrest, foglamps and interior trim in aluminium. Further standard features are 18-inch wheels running on 225/40R18 tyres at the front and 255/35R18 tyres at the rear. The radial-styling 216 rims measuring 8 and, respectively, 8.5 inches in width and proudly bearing the BMW Motorsport logo come from BMW’s FIA World Touring Car Championship (WTCC) racing car.
Apart from the mirror caps in high-gloss satin chrome, the chrome-plated exhaust tailpipe also shows the connoisseur that this is the very special BMW 320si. And the red zone in the rev counter starting at 7300 rpm and ranging all the way to 8000 rpm again proves that this 3 Series is indeed a very special car.
In addition to the six colours generally available on the 3 Series Saloon with the M Sports Package, the 320si is also available exclusively in Carbon Black Metallic.

320si_e90_front

Fast-Revving Power Unit with Motorsport Technology.

The heart of this exclusive limited edition model is the high-speed four-cylinder power unit displacing 2.0 litres and developing maximum output of 127 kW/173 bhp at 7000 rpm as well as peak torque of 200 Nm/147 lb-ft at 4250 rpm.
Compared with the regular production model, cylinder bore is up by 1.0 mm to 85 mm or 3.35″, while stroke has been reduced by 2.0 mm to 88 mm or 3.46″. Instead of cast-in grey-cast-iron liners, the pistons run in special aluminium-alloy liners stacked into the engine block. Further signs of distinction on the crankdrive are the stiffer connecting rods as well as a reinforced bedplate structure.
In creating this high-speed power unit, BMW’s engine development specialists intentionally decided not to use BMW’s fully variable VALVETRONIC valve drive. Instead, they opted for conventional valve management with two overhead camshafts, rocker arms and four valves per cylinder. Doing without numerous moving components in this way, the valve drive guarantees a high standard of stiffness and precision even at extremely high engine speeds both in the limited edition model and in racing.

320si_e90_engine_front

Components from BMW’s Formula 1 Factory.
The cylinder head is an all-new development from the ground up, with the rough castings coming from the Formula 1 foundry at BMW’s Landshut Plant. Both the intake and outlet ducts as well as the combustion chambers are processed with supreme precision and surface quality by computerised machine tools. Together with the larger valves and the modified flange contours on the intake and outlet side, this ensures optimum fuel/air mixture formation. And the final point is that special spark plugs masterminded by single ignition coils initiate the combustion process.
The compression ratio raised from 10.5 to 11.0:1 also helps to boost power by 17 kW/23 hp over the “regular” model, while the engine nevertheless still runs on 95 RON premium fuel, just like the “standard” version.
Formula 1 technology is also to be found and admired in other engine components such as the rocker arms coated in a special process developed specifically for BMW’s Formula 1 power units.

320si_e90_side

The four-cylinder in this new special model reaches its peak output of 127 kW/173 hp at 7000 rpm, with engine speed being limited to 7300 rpm. Thanks to the intake system with variable intake manifold length (DISA) and variable camshaft adjustment (bi-VANOS), torque is up to a maximum of 200 Nm or 147 lb-ft at 4250 rpm.
To take the high temperatures in motorsport into account, BMW’s engine specialists have focused in particular on the flow of coolant optimised by large cross-sections in the cylinder head. The radiator in the six-cylinder models, in turn, ensures a good balance of temperatures at all times.
The cylinder head cover made of special carbonfibre makes an important contribution in reducing the weight of the car by approximately 10 kg or 22 lb versus the BMW 320i. Proudly displaying its qualities at very first sight, the cylinder head cover not only demonstrates a direct link to motorsport, but also lowers the engine’s centre of gravity by reducing weight at the highest point.
The engines are largely hand-built by specialists at BMW’s Hams Hall engine plant, from where they go straight to the assembly process at BMW’s Production Plant in Munich. The BMW 320si is available exclusively in Europe with both left and right-hand drive.

Sporting Agility and Superior Handling.
The six-speed manual gearbox of the BMW 320si is laid out to give the car its top speed of 225 km/h or 140 mph in sixth gear. With its unladen weight of 1350 kg or 2977 lb (DIN), this sporting high-performance saloon accelerates to 100 km/h in just 8.1 seconds. Acceleration from 80 – 120 km/h or 50 – 75 mph in fourth gear, in turn, takes an equally fast and impressive 7.7 seconds. And last but not least, it almost goes without saying that the BMW 320si complies with all the requirements of the Euro 4 emission standard, consuming just 8.9 litres/100 km in the composite EU fuel consumption cycle (equal to 31.7 mpg Imp).
Through its concept alone, the new Edition Model enables the driver to enjoy motorsport at its best: The fast-revving four-cylinder responds immediately to the accelerator pedal, offering even greater agility and an even more dynamic response than in the BMW 320i. The engine has a powerful and sporting sound without in any way becoming loud or obtrusive, responding dynamically to the gas pedal and immediately giving the driver the power and performance he – or she – desires.

320si_e90_engine_bay

The sporting and ambitious driver will also appreciate the fact that the engine develops an even stronger braking effect when taking back the throttle, in comparison with a VALVETRONIC power unit. This is because engine load management is controlled in this case by a conventional throttle butterfly.
In conjunction with the short final drive (4.10) and the M sports suspension with 18-inch wheels running on large tyres at the front and even wider tyres at the rear, the BMW 320si allows a very sporting and dynamic style of motoring without coming uncomfortably close to the extreme limit. Thanks to its equal and well-balanced axle load distribution, in turn, this exclusive Sports Saloon also excels through neutral behaviour and superior agility on the road – which explains why the experienced driver at the wheel of the BMW 320si is able to lap the legendary Northern Circuit of Nürburgring in less than nine minutes.
To properly cope with the even more powerful engine, the BMW 320si comes with an even larger and more powerful brake system: Both front and rear inner-vented 16-inch disc brakes ensure optimum acceleration at all times. And this very special car also features extra-large wheel mounts.
Limited to 2,600 units, production of the BMW 320si entering the market at a price of Euro 32,150.- will be starting in spring 2006. The car will be making its world debut at the Geneva Motor Show in March of next year and BMW dealers will be taking orders as of December 2005.

e90_wtcc_front_side2

The Foundation for Motorsport.
Proceeding from the Limited Edition BMW 320si, BMW Motorsport has developed a racing version with engine output of no less than 275 hp. This motorsport version of the BMW 320si will be raced worldwide in 2006 in the FIA World Touring Car Championship (WTCC) and other racing series held under the Super 2000 Regulations, which means that BMW will be continuing its long and great tradition of customer sport also in the year 2006.
Touring car racing is indeed BMW’s most successful racing discipline so far, with the Company bringing home more wins and victories in this category than anywhere else: Twenty-four FIA European Championships as well as the so far only World Championship ever awarded in 1987 and the new Championship in 2005 – this is the impressive list of achievements proudly boasted by the BMW brand. And in the last two years, BMW, racing the 320i in the European Touring Car Championship, has brought home not only the Manufacturer’s Title, but also – in 2004 – the Driver’s Championship.
In 2005, finally, BMW won both the Driver’s (Andy Priaulx) as well as the Manufacturer’s Title.
Now the motorsport version of the BMW 320si seeks to continue this unique story of success.

[Photos by Nikos at GCZ and bmwheaven ]

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