BMW 135i e82 aFe Power Aftermarket Exhaust Review

Many enthusiasts have followed the BMW 135i from day it came out in 2008. Who wouldn’t want a modern-day BMW 2002 Turbo tii? The 135i is basically a modern day 2002 tii that is based on a shrunk down e92 3-series platform, which makes it that much more fun to drive.
The only major issue that I had with the 135i was not the power, especially not the top end power. The issue was in how quiet the exhaust note sounded compared to several previous cars that I’ve owned before with stock exhaust. A good refined and/or brutal exhaust noise makes a huge difference in adding flavor to the car. That’s when all of my research started. The 135i is a very tunable car, so there wasn’t a lack of aftermarket exhaust systems for it, ranging from full exhaust systems, down pipes, high flow cat, to cat back exhaust, and everything in between. Having so many choices  is a great thing. I remember having cars with a very small amount of aftermarket direct bolt on choices.

135i Sky

The other side of having many choices is not so great because I spent a few hours a week doing research trying to filter out the right exhaust. I had a limited budget of around $600 for an exhaust system at the time, and didn’t want to mess with SMOG issues in California. Ideally, a full exhaust system with down pipes, high flow cats, and sport muffler would be the perfect recipe to bring out most of the power out of a turbo charged car without re-flashing the ECU, etc… But as I mentioned before, I wanted great sound and performance, within my budget, plus I wasn’t sure how long I would keep the 135i for.

Car Maker: BMW
Year: 2008
Model: 135i (e82)
Engine: 3.0 liter twin turbo inline 6 (N54)
Transmission: 6 speed manual
Body Style: Coupe
Trim: Sport Package
Exhaust Modification Type: Cat Back Exhaust
Purchased/Made: Purchased
Exhaust Brand: aFe Power

It was a no brainer to just buy an aftermarket exhaust instead of making a custom exhaust for the 135i. As I mentioned, there are so many exhaust choices for that car. I decided to buy an aFe (Advance Flow Engineering) Power cat back exhaust system for my 135i.

The reason I went with aFe was simple, one of the lowest priced 135i cat backs, great reviews, 15lbs decrease in weight as compared to stock exhaust, and a small increase in horsepower and torque at the flywheel, 11.5hp@5500 rpm and 9.5lb-ft@3100 rpm respectively (while using aFe’s 135i air scoops, which I didn’t purchase).

Another major factor for me was exhaust drone noise in the car’s cabin. The manufacturer and some customers had claimed that the aFe exhaust had no traces of a drone. Good point,  but I will discuss that in more detail later in the review.

BMW 135i E82

Purchase and Delivery:
The 135i aFe exhaust was being sold on Amazon at the time for $469.95 plus free shipping. You just can’t beat that, here is a link to the 135i aFe Exhaust. I placed an order for a stainless steel exhaust (black tips are optional) on Amazon on a Sunday evening, paid an additional $30 for rush delivery.  I had the exhaust delivered by Wednesday evening. That was fairly quick. You can find the Black tipped aFe exhaust here.

The exhaust was shipped in this huge solid cardboard box with an aFe logo on it. Out of my excitement, I opened the box right away in my living room exposing this fully polished stainless steel exhaust system. Fully polished SS instead of just having polished stainless steel tips with non-polished tubing as the aFe stock photos show (that must have been an early development version of the muffler). After inspecting the muffler, I was very impressed with the quality of the welds, the polished SS finish, and the angle of the exhaust tips.

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Installation of the aFe exhaust system on the 135i was a breeze. That same evening, with the help of one of my friends, which happens to be a very good driver and drifter, we removed the old muffler. We then installed the aFe exhaust in about an hour and a half.

Here are the steps to install the aFe exhaust (a near DIY guide).

  1. Back up the car onto a pair of plastic ramps or jack up the car from the back (put the e-brake on, turn off the car and let the exhaust cool down, follow the common sense safety procedures, blah blah blah).
  2. Remove the rear bumper’s unpainted grayish plastic diffuser using a Phillips screw driver.
  3. Loosen up and remove the front 2 bolts connecting the stock muffler to the mid pipe.
  4. Unplug the small rubber hose (connected to exhaust flap solenoid) from the stock muffler (near the rear bumper), then plug the hose with a small plastic plug that’s provided by aFe (located in a small plastic zip up bag inside box). Tuck the rubber hose away from the muffler and zip tie it, because there is no use for it with the aFe exhaust.
  5. Remove the front hanger first, and then proceed to remove the middle hanger, then the rear driver side hanger that’s located in a tight corner close to the bumper.
    • Tip: Apply a small amount of dish soap (don’t spill any soap on the ground that way you don’t slip and fall on it later).
    • Tip: Keep the rubber bushing intact because you will use them later.
    • Tip: This is where your friend will come in handy. You will need help in pulling and wiggling the exhaust to get the hangers loose from these extremely tight bushings.
  6. Remove the stock exhaust completely. At this point you will notice how freakin heavy the stock exhaust is compared to the aFe exhaust.
    • Tip: Place the stock exhaust in the aFe exhaust box for easy clean storage, or for the time you sell your stock or aFe exhaust in the future.
  7. Reverse all the above steps.
  8. Turn on the car, and marvel at the cold start noise that your 135i generates with the aFe exhaust installed (I dare you to not smile at this point).
  9. Drive your car down off the ramps, let it idle until the engine warms up, then take it for a test drive.

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135i rear bumper performance exhaust tips afe

Driving Impressions:
The first time I turned on the 135i after installing the aFe exhaust system was when the engine was cold. So you could only imagine how that made me feel. You are taking a super quiet and smooth stock BMW exhaust out, and slapping on what basically accounts to a straight pipe (other than the side branch that controls droning). It sounds absolutely AWESOME!! Link to the 135i aFe Exhaust.

The cold start is super deep and super loud. To give you an idea, my car parking spot is underneath the building that I live in, which is turn is underneath the street level. I turn my car on in the morning, and immediately leave my parking garage onto the street. The cold idle sound shakes the living hell out of my building, which has gotta suck for my neighbors (I have to admit, it’s cool after all).

Cold start, moving car (HD Video)

My first drive in town left me with the impression that the car had lost a tiny bit of power. But what I think happened was actually the overwhelming noise that the new exhaust was producing compared with the stock exhaust (or at lower speeds, it could be the loss of back pressure) was much louder, causing me to feel that the car was slower. In reality, it wasn’t slower.

Driving around (HD Video)

Basically, I’ve had more time behind the wheel with the aFe exhaust on my 135i, rather than with the stock exhaust. The noise the car makes is just amazing. The low rpm’s in super deep… Let’s say you’re going 35mph in 3rd gear, drop it into 2nd gear, and the exhaust sounds like a 1000cc super bike just flew by, with the car actually flying by. It screams at WOT.

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Freeway and top end performance has improved dramatically, you can ask the owner of a stock e92 M3 in SoCal about that (I still love and respect the e92 M3 and would love to own one) or the previous generation Jeep Grand Cherokee SRT8 (which I respect still for an SUV).

aFe 135i after market custom exhaust BMW e82

The only negative thing I have to be honest about is that there is a drone at lower RPM’s. Between 2000 RPM and 2800 RPM, which is mostly cruising revs in town at 40mph, or freeway speeds between 60 and 78mph. You can take care of that if you switch into a lower gear to have your engine rev around 3000 RPM where there drone disappears.

Additional Information:
One thing that I’ve noticed while cleaning the exhaust tips is that the exhaust can be easily moved left and right, causing the tips to hit the bumper’s valance opening. But that’s only apparent if you physically shake the muffler left and right. Nothing that a minor adjustment of the hangers can’t take care of.

“Down shift to second gear, and the exhaust comes to life”

I haven’t had any real issues with the exhaust since the installation. The cool thing about the aFe exhaust is that most people cannot tell that the car has an aftermarket exhaust, well, until I turn the car on. It looks near stock, and the oversized polished stainless steel tips follow the contour angle of the rear bumper, which adds a little bit of muscle, while maintains a classy BMW look.

Not to mention the amazing turbo overrun noise that you can clearly hear if you gun it in 1st or 2nd gears then let your foot off the gas. Or the cool deep gurgling or bubbling exhaust noise that comes out of the exhaust when you let off the gas at low speeds. What more can you ask for from an exhaust system for around $500?

Click on the direct link to the Amazon listing for the aFe 135i. It’s much cheaper now, plus they have the Black tipped aFe exhaust, which they didn’t have when I bought it.

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1 Comment

  1. John F. says:

    Nice BMW E82 135i. I actually know a guy that just ordered the 135is that’s just came out in the USA. Just wondering if there will be any difference in performance.

    John F.