[Eric in SD]

After a month of lurking on this board and a lot of reading I developed a plan to upgrade the performance of my recently acquired 2008 E92 328i 6MT with the N52 motor. I installed the upgrades one at a time. This allowed me the chance to separately judge the improvement each upgrade provided. Here is my review:

The Euro Intake (sourced from ECS Tuning) went in first. Very easy install, less than an hour, a direct OEM replacement. There was a noticeable improvement in performance, particularly in the low RPM’s, but also throughout the operating range. There is a slight change in tone from the engine, sort of a deep baritone voice coming on as you accelerate, but very subtle. This mod in and of itself provides a noticeable and worthy improvement in performance and throttle response.

Step two was the BMW Performance Exhaust (from Tischer BMW). I preplanned the install and obtained a sawsall for the cuts required. This took me about 2.5 hours by myself, delayed by my agonizing on exactly where to make the cuts. It was challenging to do this single handed with no lift, but a determined hack mechanic will not be dissuaded! Performance improvements were hard to judge with this mod because the exotic sweet sounds this exhaust emits confuse your perceptions. I tried to block that out by rolling up the windows and focusing on just the performance but I found it nearly impossible to separate the sound from the actual power gain. Emotions aside, I am afraid this mod is mostly ear candy. But what a sweet sound it makes! And I have to remind myself that I am laying the foundation for the next modification.

A couple of days after the PE install I got around to swapping out the stock paper cone filter in the Euro intake with the K&N filter (also from ECS Tuning). This change resulted in a little more responsive throttle, stronger pull from down low, and a little more urgency in the higher RPM’s. I also noticed a little different and slightly louder sound with the K&N. I am split on whether this is worth the $50 dollars it cost, maybe it will pay for itself because the filter is reusable…

The final step was to get the Active Autowerke Stage 2 tune for the N52. I spoke to Andrew at AA and decided to have the install done locally at Oceanside Motorsports. Neal at OM was great to deal with. OM has quite an impressive high tech setup to perform the required procedure. The download/upload went very smoothly from my perspective and took about 2.5 hours while I waited.

I am not kidding you; AA tune provides a quantum leap in performance, better than I expected, and throughout the power band. Something good seems to happen just above 4000 RPM and the power builds up to 6,500 RPM before leveling off. I rarely shifted above 5,500 RPM before these mods but the power and sound all the way to redline is so addicting that I find myself heading there every chance I get. The improvement is not just in the higher RPMs. The motor pulls much harder right off idle. Starting out with the clutch fully engaged under full throttle, the tires will break loose as you go over the slick crosswalk stripes, giving a little chirp. I think this 328i now pulls almost as hard as my son’s 1998 E36M3 (CA intake, AA exhaust, M50 manifold, 540i MAF, AA tune). Though I think he would still pull ahead of me with his 200+lb weight advantage. This car flat out rips and I couldn’t be happier.

The N52 motor is sadly the last in a long line of BMW's naturally aspirated inline sixes. There is something primal about the sound of these inherently balanced motors eagerly winding to their redline that stirs the soul. I can’t say enough about this overall package, it has really transformed my mild mannered 328i into a little beast. It is like a completely different vehicle to drive.

I am fortunate that I could do these upgrades all at once and the install sequence was one of convenience. If I had to prioritize the upgrades and wanted to focus only on performance I would do them in this order: 1. Euro Intake (with or w/o the K&N), 2. AA tune, then 3. The PE (not a performance upgrade IMO). Of these mods the most dramatic improvement was the AA tune.

My hat is off Andrew and the AA guys for developing a fantastic tune for the N52 motor. Next I need to give a shout out to Neal and Oceanside Motorsports for the great professional service with the install. And lastly thanks to everyone on this board for posting their opinions, it helped me make up my mind on what to do.

Cheers,
Eric