The BMW 335 N54 vs N55 Engine by Vanguard Performance, Inc

In late 2009, BMW introduced its new series of motors for the 1-series, 3-series, 5-series, and Z-coupe vehicles, the N55. Though the N55 engine has the same peak performance specifications as the outgoing N54 engine (300hp and 300ft/lbs of torque) the engine has some substantial differences enthusiasts should be aware of.

For the 2010 model year, the N54 engine is still available in the BMW 335is model.

The new inline 6 cylinder N55 gasoline engine.

The new motor from BMW has three defining features: VALVETRONIC, High Precision Fuel Injection, and TwinPower Turbo Technology. The engine is an all-aluminum block and shares the same 10.2:1 compression ratio as the N54. The addition of VALVETRONIC to the engine is an addition over the N54 model, but the main item of interest in the new engine is what BMW terms TwinPower Turbo Technology.

TwinPower Turbo Technology in the N55

BMW’s TwinPower Turbo Technology is substantially different from the outgoing N54′s twin-turbo powered setup. With Twin-Turbo, two small turbochargers are used to increase the engine’s output, both spooling up at the same time as RPMs grow. With BMW’s new TwinPower technology, the N55 actually features only a single turbocharger instead of two working in concert.

The single turbocharger of TwinPower design is what is known as a twin-scroll turbocharger. It is an attempt to combine the advantages of using two small turbochargers and the singular housing design of a single turbocharger setup. With the twin-scroll design of the N55, BMW claims an advantage in both torque and the RPMs at which maximal performance arrives combined with an increase in fuel efficiency. See the Dyno plot.

N55 Performance

The outgoing N54 engine is being kept for BMW’s performance lineup in the 335is and Z sDrive35is. Vanguard speculates that that does not necessarily signal any deficit in potential of the N55 engine to tuning, but rather a move by BMW to make sure that their excess inventory and tools are used for a maximal return on their investment. For consumers looking to tune their cars past factory specifications however, it should be taken into consideration that most stable tunes and modifications for the 3-series are currently tied to the N54 platform and will continue to be that way until the newer model 3-series arrives in the next few years. For those looking to modify their BMW cars, the most mature tuning platform will the N54 engine for the time being.

Vanguard Performance E90/E92 335 N55 Exhaust

The Vanguard BMW 335 exhaust fully supports the N55 platform as well as N54 engined cars. Vanguard’s adjustable exhaust tip design allows for perfect fitment for both sedan and coupe models, making it the best exhaust choice on the market for both N54 and N55 platforms as well as E90 and E92 models.