The BMW N55 engine is already regarded as one of the best in the business, even though it was released just 2 years ago and replaced another legendary unit, the N54 one that powered the 1M Coupe.
Even though the N54 had 2 turbochargers and the N55 has only one, the power output levels are identical and the latter can also be taken over 350 HP with ease. Steve Dinan, the founder of Dinan Motorsports even offered to make a movie explaining exactly how the engine's power output is increased.
Going for one of his company's upgrade kits will take your 3-liter 6-cylinder engine up to 375 HP and 400 lb-ft (542 Nm) of torque, almost 70 HP more than the stock version. Those are some pretty good numbers and, if you're still not convinced, watch the video below. Maybe Steve will change your mind.
How exactly is it done?
What Steve is actually showing us here is the Stage 3 upgrade. What this means is that unlike other tunes that only change the car's ECU map or have a chip tune installed, this is the real deal. The power increase is rather substantial and that implies a couple of important add-ons.
Apart from the ECU tune that is, of course, present here as well, the E92 335i in the video also received a new oil cooler, new intercooler, intake and exhaust. That's because the N55 engine will operate at new, higher parameters and the rest of the parts inside the engine bay need to keep up.
The temperature of the oil goes up by a bit using the standard one that was designed for an output of 300 HP while the intercooler will also be overwhelmed. Naturally, more gas will be burned and that calls for more air (hence the intake) and a bigger set of pipes going to the back, to get rid of the fumes. That's about it. A complete kit such as the one seen on this car would run you in excess of $5,000 without labor.
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