The new (F30) BMW 328i possesses a potent four-cylinder turbo engine (N20), recognized with a 2012 “Engine of the Year” award, that provides a solid alternative to the 3.0L turbo in the 335i. Many people are extremely curious about the N20’s tuning potential, so we jumped at the opportunity to test new products developed by Evolution Racewerks (ER) in Baldwin Park, CA.

The ER team produced a free-flow downpipe and high-flow intake system before partnering with BMS Tuning for the “Juice Box” stage 1 piggyback management system.

Before we start any test, we need to establish solid baseline numbers for accuracy. Fortunately, European Auto Source (EAS) in Fullerton, CA, was kind enough to provide its expertise and DynoJet dynamometer for the task. Once strapped down, we decided to take an average on all runs throughout the day in order to give a fair representation. Steve Lee from EAS established our baseline of 235.6hp at 5300rpm to the wheels, and 256.3 lb-ft at 4400rpm.

Juice Box

Letting the car cool down, Fred Su from ER, along with his assistant Rodrigo Rodriguez, installed the Juice Box. It plugged into the factory ECU (located next to the driver’s-side hood hinges), while the remaining cables were plugged into the air intake, boost and fuel sensors (full fitting instructions are provided).

Starting the next series of dyno runs, the car immediately sounded more menacing and appeared more responsive. The 328i averaged 261whp at 5500rpm and 279 lb-ft at 3600rpm, representing a gain of 25.4hp and 22.7 lb-ft of torque at the wheels.


“Time for the real work,” stated Fred as the task of removing the stock exhaust system began. With ER and EAS staff on-hand to help with the removal, the stock exhaust system was off once Rodrigo hammered the joint between the cat and exhaust. Take note, the stock exhaust is extremely heavy, so be prepared.

The car was then lowered to access the clamp securing the downpipe to the turbo. Transferring the sensors to the new ER downpipe, the installation could begin. It took 45min to complete, with the longest time spent convincing the clamp bolt to thread in the tight engine bay.

Our dyno runs began again and the numbers from the downpipe and Juice Box climbed to 270whp at 5500rpm and 289.2 lb-ft at 4000rpm. At one point, we actually saw torque hit 298 lb-ft and boost reach 22psi, but it was excluded in order to maintain our average readings.

Note: the ER downpipe is not smog-legal in some states.

Evolution Racewerks

What began as a custom fabrication shop in 2004, ER is located in Baldwin Park, CA, and has built professional drift and Time Attack cars. However, it’s best known for intercooler, exhaust and intake systems for the Audi A4, S4 and BMW 135i and 335i. Many of these products were track-proven on their Time Attack BMW 135i racecar. The 135i set a track record at the 2011 Redline Time Attack event in Phoenix, winning the series.

Simply put by company president Fred Su, “We’re in the business of creating everything the customer wants for instant power gains.”


The ER air intake kit was easy to install because BMW made it simple to remove the stock airbox. By undoing one bolt and lifting it off two grommets, Fred was able to fit the intake in 5min.

Once the sensor was transferred to the ER intake, we were ready for our final dyno with all three components. However, we were surprised to see F30’s horsepower numbers drop by 1hp; while the torque climbed 3 lb-ft and peak boost held 21psi between 4000-5500rpm.

After analysis, we decided the minor dip is within the tolerance of the dyno and can’t be felt on the road, whereas the torque gain was noticeable. What’s more, the intake creates smoother acceleration through the power band, enhancing the previous two additions.


Finding gains on the dyno is always exciting. Finding gains after a few hours of work, feels even better. The Evolution Racewerks BMW 328i proved that quality parts mean you can enjoy significant performance gains after a day’s work, resulting in more fun on the track.

Finding an average of 35hp and 36 lb-ft at peak, at the wheels is a worthwhile exercise, especially when gains under the curve were bigger than that.

With output greater than a stock BMW 335i, the ER 328i exhibited impressive responses when we took it for a spin around the block, even with Fred, Rodrigo and myself in the car. We couldn’t help but smile at a job well done as the tires squealed in agreement.


Located in Fullerton, CA, European Auto Source specializes in OEM+ and aftermarket products for all your BMW performance needs. What started as an online parts distribution company has quickly became a test-n-tune shop for everything they stock, including many parts they develop in-house. EAS started racing to ensure its products are top quality and that they provide the fun factor that’s promised.

ER 328i

The Evolution Racewerks 2012 BMW 328i is equipped with an ER downpipe, intake and stage 1 Juice Box, as tested. To give the car track performance, the company also fitted a 380mm Brembo big-brake kit along with a set of staggered 19" MORR wheels with a frozen bronze finish. They were wrapped in (235/35 and 265/35) Toyo Tires. Since the stance is always important, a set of prototype CKS coilovers were added. Future plans include an ER intercooler and full exhaust system.

Parts Retail Price
Juice Box stage 1 $379
ER downpipe $495
ER intake $195
Brembo GT BBK $4350
CKS C1 coilovers with Swift springs $1950 + $350
19" MORR VS8.2 MonoForged wheels $3400 (+$400 for bronze finish)

Evolution Racewerks
1445 1/2 Virginia Avenue
Baldwin Park
CA  91706
European Auto Source
4015 E. Leaverton Court
CA  92807
By Ezekiel Wheeler
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