It's been too long since we last visited our 2012 F30 BMW 335i project. In fact, our last installment was in EC 4/13 when we compared our Mineral Grey car on its H&R Street Performance coilovers, 20" HRE C100 wheels and Nitto Invo tires to a similar car from LTMotorwerks. Our intention was to compare its suspension to the KW Variant 2 coilovers on the second 335i since we rarely see tests like that.

It was a fun exercise and, while we love the suppleness of the H&R components, the KWs did appear to provide slightly more control at high speed. You can read the full report in the 4/13 issue or online at

The ensuing delay can be attributed to the lack of available parts for the F30. But having waited for the aftermarket to get its act together, we decided to go with official BMW M Performance parts, available from any BMW dealership or online at

There's a comprehensive catalog of officially authorized performance and cosmetic components. These can either be financed and fitted on a new car, or added to an existing vehicle such as ours. There are parts for most models in the BMW range, so you don't have to own a 3 Series, but all the parts are OE quality, as you'd expect, and won't affect your factory warranty. When you visit the website it will display component prices and fitted prices, so you know what to expect.

We limited our cosmetic upgrades on our car to black kidney grilles and carbon mirror covers because we wanted to focus on the performance side. So we would also fit the engine Power Kit, big brakes and exhaust. This was fairly ambitious in our tight timeline, aiming to have the car ready for Bimmerfest and subsequently run the 335i against one of its competitors in the next issue.

To help us, we enlisted european auto source in Anaheim, CA for the mechanical parts, and to verify the improvements on their dyno. We'd also had the assistance of local BMW tech, Derek Vieira, who had worked on previous projects and was very familiar with the correct installation procedures. He would install the grilles, mirrors and engine hardware, while EAS worked on the brakes and exhaust before dynoing the Power Kit software.

Kidney Grilles

Fitting is relatively straightforward but you must be prepared to get stuck-in. The correct procedure would be to remove the front bumper but Derek found a shortcut...

Begin by undoing six T30 screws on the top edge of the bumper, under the rubber seal. There are also two T20 screws above the headlight housings.

Once removed, pull the top of the bumper away from the car and get your hand behind one of the grilles. Push the middle of each securing tab to release them. Work your way around the tabs to remove the grille. You'll need thin arms, long fingers and patience.

To fit the BMW M Performance black grilles, simply position and press until all the clips snap into place. You may need to apply some force. Then replace the screws in the top of the bumper and refit the rubber seal to finish.

Carbon Mirrors

Using a plastic blade and some force, lever behind the mirror glass to snap it out of its retaining clips. Then disconnect the heating wiring. The plastic mirror cover is held by three pinch clips, which should be released.

The new BMW M Performance carbon fiber covers are secured with supplied T10 screws and washers. To accommodate these, you need to bend or break the plastic tabs in the base plate for clearance.

Unlike the plastic covers, there's no ridge along the top edge to locate the carbon pieces, so the seal isn't as good. However, the screws seem to hold the new covers in place properly.

Finally, refit the glass by placing it over the center circle and wiggle it until the clips snap into place. It might be advisable to work with a cloth under the car in case the glass falls.


The BMW M Performance exhaust replaces the rear muffler on the 335i with a stainless steel part that has chromed 3" tailpipes (rather than the stock black tips on our Sport model) that are etched with the "M" logo. The muffler is fitted with the flap actuator to control backpressure, is supplied with full instructions (including a guide for where to cut) and comes with a large pipe clamp.

Arriving at european auto source, the first task was to mark the stock pipe for the saw cut. Measure carefully because you want the tailpipes to be in the correct place.

Once cut, disconnect the vacuum hose from the flap and undo two 13mm bolts on the hanger. The muffler can then be removed. The hanger should be transferred to the M Performance exhaust.

Before we fitted the new part we weighed both mufflers. The stock piece was 24.2 lb and the M Performance replacement was 21.3 lb, saving us almost 3 lb.

Having filed the sawn pipe smooth, slide the supplied clamp over the OE system and fit the end of the new muffler into the clamp. Then bolt the hanger back onto the car. Tighten the clamp once the tips are aligned in the bumper apertures. You then want to reconnect the flap.

This is a 20min DIY job, provided you have a lift and a good saw to get through the stock pipe.

Power Kit

As a relatively new addition for US cars, the BMW M Performance Power Kit in this instance consists of engine software, a new air box plus an M Performance engine cover that lets everybody know you have something sepcial.

Our car, being one of the very first 2012 models in the country, it couldn't be reprogrammed with a software flash, so a replacement ECU was supplied that would allow us to flash it. This makes our car more expensive but we're assured the results would be the same.

Installation of the hardware was straightforward. The stock engine cover sits on four columns, secured by rubber bungs. To remove, simply pull upwards. You'll need to exert some force but it will come off. Fitting the new engine cover simply required it to be pushed into place.

The replacement air box was another simple installation. Start by releasing the four metal clips around the air box lid. Then release the MAF sensor plug and unscrew the inlet hose clip from the other side of the engine bay. The plastic hose lifts off a rubber bung and is removed with the air box lid as one piece.

The base of the air box sits on another two bungs, so simply pull it upwards and away from the lower ducting.

The new base unit has an additional intake, outlined in orange. This will increase the air drawn into the intake and has increased induction noise slightly, as well as turbo whistle.

Push the new base unit onto the bungs, refit the filter element and the lid with new clips supplied. Then screw the inlet pipe back into position and reconnect the MAF.

For most owners, the installation will be complete. The car must then visit a BMW dealer to have the software flashed. It will require a software update as well as re-coding, so could take 3-5 hours. Our car required the ECU to be fitted, which was a more complicated job because of the ECU placement. It was then updated and flashed.

The overall flashing procedure is far slower than a software upgrade by aftermarket tuning companies, but BMW is re-coding and updating many functions on the car simultaneously, meaning this part isn't a DIY task.

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