The convergence of little things.

The convergence of little things.

"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, we tackle the hard part about doors: the interior. 

We strip the original doors and I document all the little things that make an OE door fully functional
. I draw the line between used parts that will be transfered and others that would be replaced."
- Matt

Doors are complex. 

The challenges in creating and fitting a carbon fiber replica of original doors are many. Within the door itself are held various safety, security, weather insulation and electrical accessories that require perfect fitment to retain OEM functionalities. 

Doors need to lock, unlock, be air & waterproof, fit an airbag, hold and power frameless windows up and down, hold mirrors all the while holding and connecting to door cards with its share of electrical accessories. 

This is also where money spent on new parts could save you time. 

Considering these are 20 year old cars, you'll also want to splurge to create the feeling of a truly brand new door with must-have-while-you're-in-there replacements.

You'll understand most go the "Motorsport" door route as discussed in the previous entry - but we want it all

But first, safety. 

A major feature of the 1:1 carbon doors is its compatibility with all OEM safety components. 

The OEM metal crash bar is fitted and the doors have provisions to fit the driver side air bag. Additionally, the doors are manufactured with kevlar composite inserts on the inner shell for improved elongation of composite fibers in case of a crash.

Unlike the E9x M3, the E46 M3 didn't have any airbags in its seats. Instead, there were only one airbag situated on the driver side door. 

Stripping the OEM door. 

With paint out of the way, the original BMW doors were pulled out of storage and laid on X stands. We started with the passenger side doors to be prudent - they have a few less components than drivers.

Having handled the carbon doors for the last few months, we had forgotten how heavy the metal doors were. The metal door shells weight 38.5 lbs. Fully assembled doors are easily over 60 lbs.

The carbon door shells weight just under 8 lbs. You can read the initial entry for more info. 

The insulation foam. 

To get to the accessories, you need to remove the foam. I had previously botched an actuator repair and did what they tell you to not do. I tore that foam a bit. Mark it up as expense #1. I ordered new foams. 

The foam is a crucial component of the weather proofing of accessories. You want to avoid gaps here. 

The original foam was sealed with urethane. We cut through it to remove it. 

The window, its rails, and motor. 

Commonly called the "Regulators", the powered windows sit on rails bolted to the doors powered by an electrical motor. The motor is heavy, and was fitted near the hinges for packaging purposes, and right next to the front rail. 

We got tap wires out to activate the motor to move the window upwards. 

With the window up, it revealed this bolt on the outer rail. 

The window got pulled and the outer rail came out easily. 

Then starts a game of wiggling, searching for angles to pull the motor out along with the inner rail. 

After squeezing fingers and hands against the metal shell one too many times, we got it out.

It's one big piece, you want to avoid having to separate its components from the complete assembly. 

The swivelling things. 

Next up, we removed the components related to the door hinges. Once more, there are various parts coming together to create a functional mechanism with weather proofing that must be re-used, or replaced.

The studs that fit to the hinges have plates that were removed. You can see their effect on the paint.

The door stop / check mechanism was removed. This needs some fiddling to come out. 

The door harness connector was also removed. This powers everything in the door. 

The locking things. 

Doors are security components of the car - evidently, they lock and unlock. It sounds simple? That's what thieves tells themselves. BMW thus came up with a system with components that work together - or don't work at all. 

The lock actuator is held by 3x bolts.

A bit of wiggling later [...]

Bam - out! This is another heavy component of the doors, yet it fits at the outer edge of the doors. It will be interesting the carbon door feels with it. 

During part of my previous shoddy DIY in the carbon fiber trims and door handles installation, the actuator's rod fell out of the mechanism [...] and never went back in (!). 

It wasn't entirely my fault. We discovered the previous owner had broke the actuator and its rod mechanism. 

The clips were missing and mushy adhesives were spotted. The entire actuator and its rod mechanism was added to the list of things to order.

A lock is only has good as it doors handles. Those had been previously removed for paint, but their brackets were still on the original doors.

The door shell was getting lighter and lighter, but it still was a heavy sob to flip over.

The inner section of the bracket was held by a single, visible bolt. The door shell has a slight slotted section to ensure the door handle bracket doesn't slide out if force is applied. 

The outer section of the bracket was held by a transversal bolt threaded from inside the door.

It wasn't rust proof, but it was thief proof (!)

Urgh - more overspray. That's what you get with 2,000$ paint jobs. 

Luckily, a proper paint & body shop will have sand blasting capabilities. 

We adjusted the abrasive and pressure according to the material we were working with and a few light passes were all that was needed. 

The Phoenix Yellow overspray was no more. 

The weather proofing things. 

The Genuine doors have various weather proofing trims that go across the entire body of the door, both vertically and horizontally. Once more, these are key to the door's everyday use and some will need to be replaced.

On a frameless window, the most critical weather proof component is the weather strip covering the mirror's frame all the way down by the window rails. 

It's the biggest, arguably tightest fitting weather proofing strip across the door. 

I removed it to the distress of Pascal. If you look by the top corner, you'll find evidence of slight tearing - oups. 

The weather proofing trim by the bottom of the doors were removed. Clips broke off, and the previous owner's low rent paint refresh was evident. I added it to the list of parts to order. 

Small rubber caps on the bottom of the door were also transferred over. 

The metal crash bar is held by 2x bolts on each end of the door. The inner section's bolt has a cap that was transferred over. 

The outer window weather proofing trim was removed and test fitted to the carbon doors. They are stiff as they act as a guide for the powered window movement. 

They easily deform, looking frizzled and weathered. I added to the list of parts to order. 

The inner window trim was pulled out of a storage bin and inspected for overspray, tears and overall condition. 

It's an intricate part of the weather proofing components of the door. The inner section of the trim are velveted. 

The larger triangular section slide in by the door lock, offering further weatherproofing, and avoiding paint on paint contact. BMW M's frameless doors are notorious for making slight contact by the B pillar, scratching away paint over time.  

The myriad of assorted clips. 

All the interior trims, accessories, and wiring are held by a myriad of clips across the inner door shell. We didn't plan for this up ahead and transferred all the clips over - well, those that we didn't break. 

It was a waste of time fiddling with the clips, using pliers to release tension on 20 year old plastic isn't particularly fun. We should have purchased most of them new. 

Way too much care, and time went into removing the plastic clips. 

You can re-use most metal clips, or source new ones. The threaded clip below is a universal design and can easily be found locally.  

These metal clips should be reused. They are the most important for fitting the door cards properly.   

They are metal, and held by pressure, and 2x tabs sliding against cut out sections in the door's frame. 

The door's shell was specifically designed and manufactured for these metal clips. The thin metal sheets are compressed to create the needed gap. 

Spot the black clip by the weather proofing rubber trim. We evidently broke the clip in the process of learning its design. This isn't clipped in - it's rotated in and pulled out. 

With all the accessories removed, it was time to transfer all of them. 

Up next: many small adjustments are made to the carbon doors and we finally get a feel for them on the car. 

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