In naturally aspirated form, the M276 has 3.5 liters of displacement and 302 horsepower and 273 pound-feet of torque. Turbos take horsepower to 333 and torque to 354 lb-ft. Mercedes drops the displacement to 3.0 liters for the turbo motor by reducing the bore from 92.9mm to 88.0mm and the stroke from 86mm to 82.1mm. This is likely to keep the motor from eating into M278 V8 SL500 sales more than it already will and also because the smaller bore will leave more block material making it stronger.
As already previewed by Benzboost the turbo V6 engine is going to be a nice entry level tuning platform. Especially considering one can think of it as a small M278 V8 twin turbo and we all know how well that engine is responding to tuning. The M276 DELA 30 shares the M278 piezo electronically controlled injectors, fuel pump, oil pump, and alternator. However, it features a 60 degree cylinder angle.
Obviously the M278 and M157 turbo V8's already available for the SL have more displacement, power, torque, and ultimate potential but the SL400 will not be giving up too much to the V8 big brothers especially once tuned. This is a smart move by Mercedes and no doubt the 400 models will sell well.
The new Mercedes-Benz SL 400: Start-up with new vigour
Apr 07, 2014
Stuttgart – The SL Roadster family from Mercedes-Benz is raring to go with a new engine. The SL 400 is now endowed with a six-cylinder biturbo drive system. Despite half a litre less displacement the output has risen by 20 kW (27 hp). Plus there are 110 newton metres more torque at its disposal. The price of the SL 400 starts from 97,282.50 euros (for the German market incl. 19% VAT).
As an automotive icon the Mercedes-Benz SL blends accomplished motoring at the highest level with exquisite style. Manufactured virtually completely from aluminium, the roadster also sets the standards in the category of luxurious roadsters with its numerous technical innovations. Not forgetting that the SL is entirely suitable for everyday use thanks to its retractable vario-roof. This makes it the all-rounder amongst sports cars.
In contrast to its predecessor, the SL 400 is not fitted with a naturally aspirated engine. Instead it boasts a six-cylinder unit with two turbochargers. Although its displacement has been reduced to three litres, the biturbo drive system develops a high full-load output potential with a charge pressure of 1.8 bar, and facilitates an extremely high torque of 480 newton metres at low engine speeds. It achieves 20 kW more than the SL 350. Its torque increases by 110 newton metres and is available in the engine speed range of 1600 to 4000 rpm. Plus the efficient six-cylinder meets the EU6 emissions standard.
SL 400 technical data
Displacement: 2996 cc
Bore x stroke: 88.0 x 82.1 mm
Output: 245 kW (333 hp) at 5250 to 6000 rpm
Torque: 480 Nm at 1600 to 4000 rpm
Fuel consumption: 7.3 l/100 km
CO2: 172 g/km
0-100 km/h: 5.2 s
Top speed: 250 km/h
Like all BlueDIRECT petrol engines the biturbo engine in the new SL 400 also works with a direct injection system with spray-guided combustion, which Mercedes-Benz was the first car manufacturer to offer in series production. The system pressure is up to 200 bar, the pressure being variably optimised according to the engine's mapping. Piezo injectors enable optimal mixture formation with up to five injections per power stroke. The third-generation direct injection is supplemented by rapid multi-spark ignition, MSI. How it works: Following the first spark discharge and a brief combustion period, the coil is recharged very rapidly and a further spark is discharged. The MSI system enables up to four sparks to be discharged in succession within one millisecond, creating a plasma with a larger spatial expansion than conventional ignition.
The rapid multi-spark ignition can be controlled to vary both the timing of the sparks and the combustion period to suit the relevant operating point. This provides scope for optimising the centre of combustion and improved residual gas compatibility. The result of this is excellent utilisation of the fuel with minimum emissions.
The SL 400 also offers two extraordinary innovations as standard: the unique Frontbass system developed by Mercedes-Benz transforms the luxury sports car into a concert hall, when the top is up and down, and the highly efficient MAGIC VISION CONTROL wipe/wash system takes water from the wiper blade to the windscreen as required and irrespective of the direction of wipe.