In an effort to cater further to the performance crowd, in recent years BMW has offered up some delectable performance upgrades for its already potent engines such as the twin-turbo N54 found in the 135 and 335 models.

The pre-2011 model year 135i’s came with the award-winning N54 powerplant as BMW’s premier engine for the reintroduction of blown engines to the Bavarian line-up. Our friend Steve Maguire from United BMW of Roswell (and famed co-pilot of the BMW X6 M from One Lap of America) posted up documentation of the first installation of the BMW-approved power kit into one of their long-time customers’ donor 135i.

However, from the video below, it seems that Mr. Woodward, the happy 135i owner, may have been an excellent candidate for the power upgrade as Steve has already has the BMW-spec uprated brakes, short shift kit and a number of other factory-approved modifications.

To test and verify the results of the power kit, Steve and Steve employed the help of a local dyno shop to run three tests both before and after the kit installation. On the first series of dyno pulls, the 135i put down an impressive 290HP to the wheels – which is indicative of the long-rumored underrated engine output typical of BMW. After the kit installation, three more dyno pulls indicated that the 135i pushed 309HP to the rear wheels equating to roughly 350HP before power loss to the wheels.

From watching the video it seems that Steve Woodward is quite a happy 135i with the noticeable performance gains from the power kit. Most important to Steve is the fact that, in addition to a nice power hike, he can also maintain the warranty on the engine as it is a BMW factory power kit. For those interested, the BMW power kit upgrade includes:

1. New electric fan

2. New spark plugs

3. New radiator hoses

4. Secondary radiator

5. New DME

Note:The 1 Series Power Kit also requires the installation of the BMW Performance Air Duct Kit.

The kit should now be available through certified BMW dealerships for those looking enthusiasts for extra power gains from their N54-powered 135/335’s without sacrificing the factory warranty.

(Video and Photos compliments of Steve Maguire and United BMW of Roswell)