Learn all about the original design philosophy and technical details.
Proof that the Boxster is every inch a thoroughly well designed Porsche.
in a world where exciting new developments are being announced all the time, though the reality often turns out to be a relatively modest step forward.
All the more reason to believe that a very special group of people will be particularly pleased to hear that Porsche, one of the most exclusive carmakers in the world, has produced a new model.
It’s an open two-seater with a 6-cylinder, horizontally-opposed engine (boxer) mounted between the front and rear axles. It has 2 luggage compartments. It’s called the Boxster (Boxster and Roadster).
There are mass-produced roadsters, and there’s the Boxster. That really says it all.
The Boxster didn’t come off the shelf. Some companies might take a limousine engine and maybe an existing under body or axle assembly and simply come up with a novel way of putting them together. The Boxster, on the other hand, was developed from scratch as a completely new car. Its design is not based on a search for synergy, nor is it a computer product. It was born in the imagination and passion of a small group of people.
It’s all new, from the first design sketch to the last bolt. That’s why it arouses something which is increasingly rare in our digitised and rationalised world: emotion.
You can experience this emotion at first hand. An emotion which will stay with you from the very first impression right through the entire life of the car.
Driving a new Porsche starts with the visual impression, and the Boxster is an aesthetic delight. The styling looks right and is right; others will follow where this car leads. Its confidence and elegance stand out from passing fads and fashions.
The Boxster is the perfect embodiment of the Porsche company philosophy in terms of engineering, independence, unconventionalism and performance.
There is a new interior, new instruments and a design which has everything which has everything to do with function and nothing at all to do with mere show.
The hood is designed like a normal roof, fitting flush to the bodywork. The pleasure you take in quality will register every detail of the bodywork and every stitch of the hand-sewn leather upholstery.
The Boxster is also – like every Porsche since 1977 – fully galvanised and designed for durability even under extreme conditions. If you think that over 60 percent of all Porsches ever built are still on the road it is clear that the life expectation of a Boxster is many times that of a normal car.
In years to come people will acclaim it as a “classic”, with corresponding resale values.
Not that we want to make out a business case for the Boxster. Just regard it as evidence that there are also completely rational motives for what is essentially an emotional decision.
The Porsche Boxster 2.5 Engine.
The Boxster is a roadster. What’s more, a roadster for everyday use. If you think that means a compromise you don’t know Porsche.
Take the engine. It isn’t what it is because that’s the way a few enthusiasts want it to be, but because in the Boxster only this configuration allows the engine to meet the tough requirements which make it suitable for everyday use. The mid-engine layout leaves room for two luggage compartments and allows the best possible sports car handling. Horizontally opposed banks of cylinders reduce engine height, leaving enough space above the engine to stow the hood.
As a 6-cylinder with 24 valves and VarioCam it exceeds legal requirements and our own environmental standards while still delivering plentiful performance. Its electronic management system and the open-deck construction provide maximum safety. So all in all, this really is an engine for genuine enthusiasts.
The Boxer design features two horizontally opposed banks of three cylinders. This makes the engine flatter than a V and shorter than an in-line engine. Further advantages are the outstanding balance, resulting in low vibration, and good cylinder charging. Each cylinder has 4 valves, which optimises cylinder charging, especially at high revs. Water cooling is essential for a 4-valve engine; air cooling would not be efficient enough. Engine capacity is 2.5 litres.
Open-deck construction. The two halves of the crankcase are cast with all the channels required for oil and water circulation (diecast aluminium). Since it is no longer necessary to drill and clean out the channels in separate operations, production is simpler and safer. It also means that the Boxster doesn’t require any pipes and tubes running around the engine, with the inherent risk of faults developing at clip and screw-fit connections.
Alloy construction. The guiding principle here was to make use of the advantages of alloy construction without having to suffer its disadvantages. The advantage lies in its low weight, and the disadvantage, expansion at high operating temperatures, has been eliminated. For example, we use an aluminium crankshaft bearing housing with cast iron inserts. This keeps the amount of play in the bearings extremely low even at high temperatures.
(1) Low engine noise – it is dealt with at source (and not later by using bulky and heavy insulation);
(2) The engine needs less oil and hence a smaller oil pump which weighs less and uses less fuel.
VarioCam. VarioCam is a system patented by Porsche which uses variable timing chain tension to adjust the inlet camshaft, depending on engine speed.
That might sound rather complicated but its advantages are easy enough to understand: low-speed idling is steadier, and exhaust emissions are reduced. VarioCam boosts mid-range torque, i.e. pulling power, and delivers maximum performance at high revs.
VarioCam provides sparkling acceleration and performance at medium and high revs in particular, and is controlled by the Motronic engine management system.
Integrated dry sump lubrication. Developed specially by Porsche, this system is based on the dry sump lubrication used in the 911. With integrated dry-sump lubrication two suction pumps (one for each bank of cylinders) extract the oil from the cylinder heads, de-froth it and pump it into a kind of sump. A third oil pump forces the oil from the sump to all lubrication points. De-frothing ensures optimum consistency, giving perfect lubrication. Even under extreme load e.g. high lateral acceleration.
Oil level indicator. The Boxster has an electronic oil level indicator so the driver can keep an eye on the oil level. A conventional dipstick is also fitted, of course, and is easily accessible in the luggage compartment.
Engine cooling. High performance coupled with relatively low capacity, a 4-valve engine and increased environmental friendliness all make water cooling a necessity for the Boxster. It also protects the valves against excessive stress and premature wear and tear. When the engine is warming up, only the relatively small amount of coolant which surrounds the engine is used, shortening the time it takes to reach normal operating temperature. Once this is reached the thermostat switches over to full cooling system capacity. Like in the world of Formula 1, all coolant channels are integrated in the engine castings. The cross-flow cooling system ensures that all cylinders are supplied equally with fresh coolant. No cylinder is cooled with water which has already been heated through contact with another cylinder. The advantages are better combustion, reduced knocking tendency, reduced fuel consumption, and better exhaust emission figures.
Digital engine management (Motronic M5.2). This is the central electronic control unit for all parts and components which control and influence the engine, e.g. ignition and fuel supply. The Motronic M5.2 system ensures that the engine always operates at its most efficient, under all operating conditions, even when conditions change very quickly.
The main functions of the Motronic system include ignition timing, fuel injection (fuel metering and timing), anti-knock monitoring on an individual cylinder basis, stereo Lambda probe control, on-board diagnosis, idling, and the VarioCam camshaft control function. All Motronic functions are digitally controlled based on constantly measured and monitored input data.
Ignition. The Boxster’s ignition system features static high voltage distribution. Individual ignition coils located directly on the spark plugs ensure high ignition reliability. As there is no central ignition coil, no high tension leads are necessary which might cause interference. There is no need for a distributor either. The Motronic system controls the individual ignition coils directly. Reaction time is measured in mere fractions of a second. For example, if the Tiptronic transmission requires ignition timing to be advanced or retarded to allow smoother changes, the ignition system will respond rapidly and precisely.
Exhaust system. The engineering effort invested in the exhaust system has yielded clear benefits in terms of its ability to cut down harmful emissions. Each bank of cylinders has its own separate exhaust system, and the individual catalytic converters are equipped with efficient, low-wear metal insides.
The stereo Lambda control facility with its two intercommunicating Lambda probes analyses exhaust composition individually for each bank of cylinders. This enables very fine adjustment of the fuel –air mixture to be made for each bank of cylinders. The two exhaust systems produce a lower counter-pressure overall than a single system, making a positive contribution to performance and torque.
Idling control. The idle running speed is maintained at a fixed setting – even when you switch on the air conditioning or operate the electric hood mechanism
Sequential injection. Depending on ignition timing, cylinder temperature, exhaust composition, accelerator pedal position, rpm, etc. the Motronic system regulates fuel metering and injection timing individually for each cylinder, i.e. in sequence, to ensure the most efficient possible combustion process.
Individual anti-knocking control for each cylinder
Since all cylinders never operate under precisely the same conditions, it is desirable to monitor knocking individually for each cylinder and if necessary to advance or retard the ignition timing individually to prevent knocking on a specific cylinder at high revs. Knocking is typically caused by low-octane fuel, and can cause lasting damage to the valves.
Tuned intake system. A resonance effect is used to generate a denser mixture, ensuring greater torque at low revs and a flatter torque curve.
On-board diagnosis. A diagnostic system monitors essential components which influence exhaust emissions. This makes it easier to identify faults and prevents expensive and unnecessary repairs.
Emission monitoring. Data supplied by the Motronic system allows emission monitoring with a minimum of effort.
Maintenance. The guiding principle here is that a Boxster should spend as much time as possible on the road and as little as possible in the workshop.
To help make this possible, the alternator, power-steering pump and air conditioning system are driven via a single self-adjusting belt.
The camshafts and countershafts are driven by chains which do not need to be serviced or replaced throughout the entire life of the vehicle. With the exception of the spark plugs the ignition system is maintenance-free. The hydraulic tappets do away with the need to adjust valve clearances.