BMW 535i GT: New Single Turbo VALVETRONIC N55 Engine

New single turbo with twin-scrolls extends the torque band with 400 Nm of peak torque reached at 1,200 rpm

Here's a detail of the new BMW 535i Gran Turismo that deserves to be duly noted.

The 535i GT features BMW's new TwinPower Turbo with High Precision Injection and VALVETRONIC technology, a single turbo with twin-scrolls that puts the squeeze on the 3.0 liter straight-six gasoline engine, internally referred to as the N55 over at BMW.

This engine, as opposed to the twin turbochargers of the N54 version, is a first for BMW, coupling that single twin-scroll turbo with High Precision Injection and the variable valve management of the VALVETRONIC system. The 4.4 liter V8 that goes into the 550i GT still gets a twin-turbo but that 4.4 liter may be getting this new tech-upgrading for the upcoming X5M/X6M versions.

Distinguishing the N55's performance from its predecessor includes a broadening of the torque band, the 400 Nm now peaking pretty early at 1,200 rpms, and extending all the way to 5,000 rpms. The N55 also has a map-controlled oil pump which helps conserve energy, a first for a turbocharged engine, and the improved engine management gives it a better fuel economy and CO2 emission rating than the N54.

Naturally, speculation goes to the obvious next step, that BMW will introduce VALVETRONIC and High Precision (Direct)-Injection on a twin-turbo version of this 3.0 liter straight-six and dial the horsepower up to 360.

Sounds good.


Source: bmwblog.com

World debut: TwinPower Turbo, High Precision Injection and ­VALVETRONIC in a new straight-six gasoline engine.

The history of BMW's modern turbo engines going back to the year 2006 is characterised by spectacular power and exemplary efficiency. And now BMW is opening up a new chapter in this history, the straight-six gasoline engine powering the BMW 535i Gran Turismo consistently continuing the process of optimising engine power while at the same time reducing both fuel consumption and CO2 emissions on an engine of this calibre.

The 3.0-litre power unit, for example, is yet a further result of the BMW ­EfficientDynamics development strategy, offering a range of highlights in technology never seen before on any other engine - highlights created in the context of BMW EfficientDynamics and now ideally matched for optimum driving ­dynamics and economy all in one.

The new straight-six is the world's first engine to combine turbocharging, direct gasoline injection and fully variable VALVETRONIC valve management developed by BMW. The turbocharging process follows the twin-scroll principle already applied successfully by the BMW Group and now further enhanced consistently for use in a particularly powerful and sporting straight-six.

The combination of this turbocharger technology with High Precision ­Injection and VALVETRONIC exclusive to BMW exceeds even the response and ­efficiency of the BMW Twin Turbo power unit launched back in 2006.

Response even better than before, fuel consumption even lower.

VALVETRONIC has already proven its qualities in numerous BMW engines the world over as a particularly effective technology providing even greater efficiency. The big advantage of VALVETRONIC is the infinite control and adjustment of valve stroke on the intake valves, making the throttle butterfly used in former times superfluous. VALVETRONIC reduces throttle losses in the charge cycle process to an absolute minimum and optimises engine response since the air mass required to control the combustion process is masterminded in the engine itself and not outside the power unit with the usual "dead" volume. This ensures particularly efficient use of the energy contained in the fuel, developing a very muscular torque curve and giving the engine optimum response.

In particular, the better response of a VALVETRONIC engine results from the fact that underpressure under part load is only approximately 50 millibar, while on a conventional engine up to 800 millibar of underpressure has to be set off.

On the BMW 535i Gran Turismo the VALVETRONIC functions have been optimised again by a new adjuster complete with a fully integrated sensor ­serving above all to make the adjustment process even faster than before. Indeed, the inertia factor on the new adjuster is only one-tenth the figure on the former model, serving to further improve engine response.

Responding smoothly, directly and immediately to the gas pedal, the new straight-six is clearly the leader in its class also in this discipline. Maximum torque of 400 Newton-metres/295 lb-ft, for example, comes at just 1,200 rpm.

Apart from the optimised VALVETRONIC control unit, the newly developed turbocharger also contributes to this superiority, ensuring a particularly spontaneous build-up of power since the ducts of three cylinders at a time are separated from one another both in the exhaust manifold and the turbocharger.

In practice, this means particularly low exhaust gas counter-pressure at low engine speeds, the double ducts then enabling the flow of gas to build up greater dynamism in the exhaust manifold and powerfully drive the turbocharger blades even at low engine speeds. Twin-scroll technology thus combines the benefits of two turbochargers within one system. And now this principle adapted to the BMW straight-six with its high standard of technology marks the ongoing, consistent development of BMW's turbocharged engines.

High Precision Injection with new injector nozzles.

The VALVETRONIC system is fully integrated in the cylinder head. This intelligent and extremely compact arrangement allows a direct combination with High Precision Injection with its injection nozzles placed in the middle between the valves and, therefore, in the immediate vicinity of the spark plug in the cylinder head.

High Precision Injection in the new six-cylinder delivers fuel through innovative multi-hole valves at an injection pressure increased once again in large areas all the way to 200 bar. This ensures extremely precise dosage of the fuel injected as well as a particularly clean combustion process. And last but not least in this context, the direct injection of fuel serves to cool the fuel/air mixture and increase the compression ratio to a higher level than in a turbocharged engine with manifold injection - an advantage contributing once again to the greater power of the straight-six.

Displacing 2,979 cc, the new power unit delivers maximum output of 225 kW/306 hp. It therefore offers all the torque and muscle of a significantly larger eight-cylinder, but comes with much lower weight and significantly lower fuel consumption and emissions. It is indeed far lighter than a comparably powerful eight-cylinder and remains even 4 kilos lighter than the straight-six turbocharged engine already well-established in the market.

The BMW 535i Gran Turismo accelerates from a standstill to 100 km/h in 6.3 seconds and reaches an electronically limited top speed of 250 km/h or 155 mph. The unusually good balance of performance and fuel consumption is clearly expressed by average fuel consumption in the combined EU cycle of just 8.9 litres/100 kilometres, equal to 31.7 mpg imp. And the CO2 rating of the BMW 535i Gran Turismo is just 209 grams per kilometre.

The BMW 535i Gran Turismo, like the other two model variants, comes as standard with a wide range of BMW EfficientDynamics technology. ­Supplementing the excellent efficiency of the respective engine and the eight-speed automatic transmission, features such as Brake Energy Regeneration, ­on-demand management and operation of ancillary units including the electrical coolant pump, the electrical power assistance pump and the detachable a/c compressor, as well as consistent lightweight engineering, optimised aerodynamics including active management of air flaps, and tyres with reduced roll resistance, ensure optimum fuel economy and emission management at all times.

The power unit of the BMW 535i Gran Turismo is the first turbocharged engine to feature a map-controlled oil pump which, taking up less energy, makes a further contribution to motoring efficiency. Yet a further point is that the new straight-six power unit with turbocharger, High Precision Injection and ­VALVETRONIC, does not require sulphur-free fuel and may therefore be used without problems the world over. The final point is that the engine naturally fulfils both the EU5 emission standard in Europe and the ULEV II standard in the USA.


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Comments (26)

daniellew daniellew
If this is the new 5 design, BMW can say bye bye to my order.
Jun 14th, 2009 10:17pm
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elsonlau elsonlau
Like I said its a touch of class. This car is ideal for young and old folks. Its not UGLY!
May 31st, 2009 11:29pm
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unknownuser unknownuser
Better looking than I thought it was going to be.
May 29th, 2009 3:54am
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And then audi comes with an a8 avant
May 28th, 2009 4:12am
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thamzn thamzn
I get it. It's like a cheaper 7 Series, for people who want to feel like they are in the First Class section on an Airbus without paying extra.
May 27th, 2009 5:40pm
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reyngel reyngel
The side-profile looks alright, but the rear and front views are terrible.
May 27th, 2009 3:49pm
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carbuff carbuff
I thought this design was just a Bangle Big Butt practical joke when I first saw it but now it's reality eeeeeeeeeeek! BMW must be getting really desperate now that they finally realized what a BIG DESIGN DISASTER it is and are trying to make it fast so that people won't have to look at how uuuuuugggggly it is for very long. Sorry Pontiac Aztec owners this new BMW will be the new King of Uuuuuugggggly as soon as it goes on sale.
May 27th, 2009 3:02pm
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unknownuser unknownuser
I think the CLS is still king
May 27th, 2009 2:45pm
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schnell schnell
yeah well when they talk about the "most potent configuration...326 hp" they are talking about the massaged N54 in the F01 740i, not the engine in the 135i, 335i etc
May 27th, 2009 1:00pm
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Aesthetics Aesthetics
it weight more than 1900kg and could not go off-road. suddenly an MPV seems so promising
May 27th, 2009 11:56am
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norther norther
so the twin turbo 3.0 had 306 horses, and this one has.... 308? 309? ...or 303? how much does this engine has without the turbo...again?
May 27th, 2009 9:42am
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DieselDog DieselDog
MotorAuthority.com reports that the N55 "Peak output is still a healthy 306hp (225kW) at 5,800rpm and 295lb-ft (400Nm) of torque from an even lower 1,200rpm. Furthermore, the new N55 is also said to be more fuel-efficient than the N54..." Yet the N54 "in its most potent configuration develops up to 326hp (243kW) at 5,800rpm and 332lb-ft (450Nm) of torque from as low as 1,500rpm." Hmmm - less horsepower and less torque in a pig of a car with only automatic transmission. I'll pass.
May 27th, 2009 12:24pm
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Imasa Imasa
I don't like it now, but I haven't seen it in person. I'm sure the design will grow on me.
May 27th, 2009 9:23am
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Bonganie Bonganie
If the 5-Series gets this face then Audi is the prince !!! Where is Bangle when BMW needs him ?
May 27th, 2009 7:35am
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Emrys_Myrddin Emrys_Myrddin
You can say that again. The 5 series was a great looking car when it came out. Is still is. But this one... this front end is just... worse! Hope they redesign it.
May 27th, 2009 9:27am
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YuZi YuZi
is this a mitsubishi turbo as well?
May 27th, 2009 5:24am
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nederina nederina
fabulous engine but a gran turismo? you can call it all you want but this is infact a hatchback with a pillarless door. one of the most pointless car i've seen since the x6.
May 27th, 2009 5:19am
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Phonixx Phonixx
unfortunatly, i was eating my dinner meal while i was looking at this $%/&#$"/!$ and i didn't finnish it.......
May 27th, 2009 5:10am
0 0
The 5-series GT is more of an MPV than a 4/5-door coupe. Its not just longer than the upcoming 5-series sedan, its also taller. It isn't really that pretty, but at least its much better looking than Renault's Vel Satis.
May 27th, 2009 4:32am
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GermanCarsRule GermanCarsRule
this car roxxx.
May 27th, 2009 4:31am
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unknownuser unknownuser
Panamera is waayy better I guess A DAMN SIDE BETTER!
May 27th, 2009 4:24am
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mn07 mn07
Hmmm... More power than the twin turbo engine
May 27th, 2009 4:23am
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trspeed600 trspeed600
Are you insane? The Panamera is way better looking than this toad. Please exit now and go see an eye doctor.
May 27th, 2009 3:58am
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