The bottleneck is uncorked.

The bottleneck is uncorked.

"In this Special Series about the E46 OE+ 1:1 Carbon Doors, I document the development, logistics of getting these doors to America. With the Atlantic bridged, I cover the unboxing, fitment adjustments, installation notes and final paint & body steps. 

In this entry, I cover my unboxing impressions: both doors made it safe and sound. I review the improvements I spec'ed from the E92 variant."
- Matt

Added logistical complexity. 

I was previously able to import the E92 carbon doors using EMS to save on cost and simplify the delivery process using the national mail service. The E92 doors were shipped and delivered for under 400$. 

It was a bit of a hack: the mirror section was sticking outside the box to circumvent the maximum dimensions allowed by EMS.

Unfortunately, the dimensions ending up exceeding the maximum specifications of EMS. We got the memo when they returned the doors to the manufacturer. 

We had to import the doors using air freight via Air Canada Cargo, using my own broker and drive to the airport to pick up the package.

It did allow us to create a studier box that accommodated both doors. In the long run, this should support a safer delivery process.

I ended up having to pay close to 1,000$ in shipping costs, taxes, warehousing and brokerage costs. This drastically increases logistics costs and complexity, but it did allow us to create a single package with both doors in it.

I was able to save on duties due to the Comprehensive Economic and Trade Agreement (CETA) between Canada and the EU. Still, this is a net negative when compared to the EMS solution. 

The doors were once again very well packaged with foam on the edges, bubble wrapping and paper protecting the carbon. 

The specs. 

In March '23, I had previously received the E92 carbon doors and shared my unboxing impressions, and along with improvements for the E46 variant and subsequent production of all carbon doors. 

The previous E92 doors were delivered clear coated in gloss finish with various imperfections in the coating. 

The raw carbon. 

The raw finish reduces costs upfront, manufacturing delays and labor time for paint & body shop. Paint shops often prefer working with raw carbon parts as they can properly prepare the surface for paint.

It's a better, smarter way to do it.

The raw carbon does mean we get to see every single carbon work imperfections when unboxing these doors. 

As the doors are removed from the molds, gel coating that is applied prior to the vacuum infusion process can be uneven. 

The inner vertical carbon that traverses the door shows the matte underside of the carbon. 

Sanding marks can be seen within the goal coat. These are commonly called "pig tails". They happen when the sanding techniques are too fast, or have too much pressure applied. 

The overall sheen is meh, but we don't care. This is a better base to work from than the dust-specs & drips across the gloss clear coat we had on the E92 carbon doors. 

The overall carbon work is good considering the complexity of this part. The 2x2 weave is well aligned and conforms to the most complex shapes of the door.  This is probably the most weave deformation you'll find on this door. 

They are light. 

The stock doors without any accessories weight 17.5 kg / 38.5 lbs. The E46 carbon doors came in at 3.6 kg / 7.9 lbs without the crash bars. They add 1.8 kg per door for a complete weight of 5.4 kg / 11.9 lbs.

We're in for a minimum weight savings of 26.6 lbs per door without deleting any accessories. 

Overall, this was a surprise: the E92 carbon doors were lighter! They came in at 2.4kg / 5 lbs without the crash bars. 

The OEM hardware.

As on the E92 variant, the E46 carbon doors re-use Genuine BMW hardware in the same locations. 

The studs for the door hinges are taken from a used E46 door, cleaned and fitted to the carbon doors in the exact same location as the OEM steel doors. 

The anchor points and bolts are all refurbished Genuine BMW hardware. 

The 1:1 design. 

On complete door shells, every single cut out was designed with a purposed by BMW engineers. No liberties were taken here, all the cut outs and inner parts hat are present on the OEM steel doors are matched & replicated. 

I will to my best to identify the purpose of each cut outs when we get to final fitment. 

Outside of the crash bar, the inner Genuine BMW components are entirely replicated in carbon. 

The inner and outer shell are glued together using structural adhesives. 


The cut outs are not all perfect. The door trim sections all had extra fibres from the cutting process.

The door handle and lock section had similar issues. 

The optional crash bars.

As with the hardware, the OEM crash bars are also sourced from a used, intact door set and refurbished before fitment. They are a safety component used by BMW. I personally opted for it as this will be a street car for the most part. 

The E46 doors have a single, wider crash bar across the body of the door. The E92 had 2 smaller, ribbed metal bars. 

Additionally, a kevlar layer is added to the inner door skin. Kevlar has less stiffness and tensile strength than carbon yet deforms when going beyond its failure thresholds. These remain untested, we'll never truly know how it stacks it to the OEM steel doors. 

The bottleneck, uncorked.

The Phoenix's restoration had been on a hiatus since early April due to delayed parts and limited shop time to perform the engine work. With the carbon doors in, we're back to work on the body and a timetable is set to finalize the build. 

The E46 had been sitting doorless for months, pushed in and out of the shop daily. 

Up next: we're finally uncorked.

The doors get prep'ed, painted and fitted [...] and we are back to sanding. 

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