How To Install Race Seats in BMW 135i / 335i – Corbeau FX1 Pro

On a mission to remove weight from my BMW 135i, I decided to swap out the front seats for something lighter. The stock seats are great, but bulky. I need something that will save weight and keep me from sloshing around at the track.

My Requirements

  • Affordable
  • Lightweight
  • High quality (no eBay seats)

With a budget of $1,000 shipped for a pair of seats and hardware to mount them, I started my search. Ideally, that price would include sliders because other people drive my car and a fixed seat would be inconvenient.

I don’t want fancy, reclining seats because I’m looking for a lightweight option. My research shows that reclining seats are about 5-10 lbs heavier.

Lastly, I’m avoiding cheap knockoff seats. eBay is riddled with options that seem okay, but I don’t want to take the chance. Seats and brackets are safety equipment that keep your body where it should be.

Corbeau Race Seats

I was pleased to find multiple Corbeau seats that fit my requirements. Their Forza seat was appealing with a low price and optional inflatable lumbar support. However, I liked the looks of their FX1 Pro seat even more.

Corbeau also offers a bolt-in bracket for the E8X/E9X chassis. Their seat bracket even includes a slider, which is a huge selling point for me. Finding a pair of seats, brackets and sliders all from one manufacture will make things very easy for me!

Without wasting any more time, I put an order in for the following:

FX1 Pro Seat – Impressions

The Corbeau FX1 Pro is marketed as a comfortable, safe race seat at an unbeatable price. After receiving the seats, I’m happy to report that they exceed my expectations! They aren’t as luxurious as some of Corbeau’s more expensive options, but they are exactly what I was looking for in this price range.

I will admit, these seats are pretty comfortable for being a race seat. If I were taking the car on a cross-country road trip, I’d prefer the stock seats… but when will I be taking this car on a cross-country road trip? I’m much happier that my body isn’t flopping around when I’m ripping around the track!

The FX1 Pro has provisions for a 5-point harness and also has a mounting point on the back if you want to secure it to a cage or rollbar. It is available in different materials, colors and has three size options. The “Pro” version fits up to a 36″ waist, the regular version fits up to a 38″ waist and the “Wide” version fits up to a 42″ waist. I opted for the Pro version because my girlfriend and I are slim and it fits us very well.

It is important to note that the FX1 Pro is not FIA-certified, but Corbeau does have other FIA-certified seats available.

Seat Installation

Installing the seats into my 2008 BMW 135i was simple. The factory seats unbolt after removing four T50 torx bolts, one from each corner. Disconnect a single yellow connector and the seat is ready to come out.

Since I don’t have harnesses (yet), I transferred the seat buckles from the original seats to the Corbeau brackets.

The FX1 Pro seats were easy to mount onto the sliders with four bottom-mounted bolts. Once the seat and buckle were attached to the bracket, I installed the new seat. Be sure to plug in the seat belt sensor into the yellow connector!

They fit perfectly!

I ordered a pair of 8″ seatbelt extenders so I could snake the belt through the seat. This allows me to buckle up within the seat instead of over the top of the seat.

Weight Reduction

Surprisingly, the stock seats weigh a massive 59.6 lbs! For comparison, the FX1 Pro and bracket weigh 27.4 lbs. That’s a difference of 32.2 lbs, bringing the total weight loss to 64.4 lbs for the front seats. I’ll take it! I also previously removed the rear seats, which saved about 55 lbs.

Next up; a carbon fiber sunroof delete and carbon fiber door panels!

Airbag Light Errors

After installing the seats, I was abruptly faced with airbag warning lights on the dash and iDrive unit.

I used the ProTool app by BimmerGeeks to get rid of these error codes. Simply connect an Android tablet to your car with a K+DCAN cable and OTG adapter, open up ProTools and go to work!

Under the “Safety” section > MRS – Airbag > Coding > Standard, we must deactivate the following options.

  • Seat Mat Sensor (OC3_1)
  • Driver Seat Position Sensor (SPSF_1_CD)
  • Left-Side Airbag (SIDEBAG_LINKS_1)
  • Passenger Seat Position Sensor (SPSBF_1)
  • Right-Side Airbag (SIDEBAG_RECHTS_1)

Enjoy your new seats and lack of error lights!

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