What to Know Before Upgrading Your N55 Turbocharger 

BMW introduced the N55 platform in 2009, starting with applications like the F07 5 Series Gran Turismo. Since then, this turbocharged straight-six engine has been used across a wide range of models, including platforms like the E90 3 Series and the F32 4 Series.

Production of the N55 eventually ended in 2021 as BMW shifted focus toward the B58, which entered production in 2015. Even so, plenty of N55-powered cars are still on the road in 2026, and the aftermarket support for N55 turbo upgrades remains strong. If you’re considering an upgrade, here are a few important points to keep in mind before you buy.

Determine Your Turbo

Because there are multiple upgrade paths, the first step is choosing a turbo that matches your goals. You’ll commonly see options like the N55 GC and N55 GC+ turbos, which are designed to support different power ranges.

In general terms, the GC option is aimed at builds targeting around 600 WHP, while the GC+ is designed for higher power potential, closer to 700 WHP. You’ll also want to confirm whether your car uses an electronic wastegate (EWG) or a pneumatic wastegate (PWG), since that affects compatibility.

If you’re building a complete package, it’s also smart to plan for supporting parts. An aluminum intake and the correct installation kit can help you get the best results and keep the install clean and efficient.

Changes From OEM Specs

An aftermarket BMW N55 turbo upgrade isn’t just about bolting on a different turbo. The value comes from improving the design choices that limit the factory unit. Many upgraded turbos start with the OEM layout, then refine key areas to improve airflow and durability.

Common upgrades include a larger and more efficient inlet to reduce restriction, along with improvements to the bearing housing oiling design and the thrust bearing system. These details might seem minor on paper, but they can make a real difference in how the car responds and how well the turbo holds up under higher load.

Going After Those Gains

Most people upgrade the turbo for the same reason: better performance. A new N55 turbo can improve dyno results and help the car run stronger in real-world acceleration, including quarter-mile performance.

It’s also worth thinking beyond the turbo itself. If your goal is meaningful gains, you may want to look at N55 turbo upgrade Stage 1 kits and other supporting mods that improve airflow and boost efficiency. When the turbo, supporting hardware, and calibration all work together, you’ll typically see stronger horsepower and torque along with improved overall engine efficiency.

Upgrade your N55 turbo at vargasturbo.com