NB2 door card to NB1 Retrofit

[kung fu jesus]

I'm looking for a little help. I'm searching around about retrofitting NB2 door cards into an NB1. I've read about the kludges of flattening/shortening the NB1 door actuator rods and cup fitment. That's not good enough.

I am wondering if I can retrofit the NB2 door actuators (the release handles with the cables, versus the NB1s rods)? It seems this would eliminate the poor cup fitment and rod modification. I realize a litle modification would be needed to mount the actuator (release handle/pull) to the door's inner skin, but I'm looking for the cleaner, best operation here.

Does anyone have info, links, pictures to how to do this the "right way"?

[HarryB]

I do not see why not.. I also imagine the actual door frames being very close to identical, but I do not know for sure.

[Demon I Am]

I tried so hard to get this to work in the 00. Looked like it would require the latches and rods, and probably the actuators, a little spot grinding, and maybe some hole drilling to get things lied up perfectly. Probably cheaper to just replace with an nb2 complete doors from Alex, or someone local. Unless you really are into doing the fab work..

[kung fu jesus]

Tony did you try to replace the latching hardware between the two? The NB2 uses cables, not rods (like the NB1).

[kung fu jesus]

I pulled these from the NB1 and NB2 FSMs online.

NB1 (part 15):

17909

And NB2 (part 13):

17910


There are some similarities. I need to look those up and see if the are indeed the same (hopefully). The two illustrations show the actuator rods of the NB1 and the cables on the NB2.

[kung fu jesus]

Furthering this investigation, I found the parts diagrams. I highlighted the areas I'm looking at.

NB1:

17912

NB2:

17913


Except the electrical connector coming out of the NB2 unit, it looks the same assembly with the difference being rods or cables.

[kung fu jesus]

So, I'm *thinking* that to make the NB2 door cards work on an NB1, I need the door latches, cups, cables, and the latching mechanism. The lock and handle linkages look the same.

NB1:

17914

NB2:

17915

From there, the mods to the inner door skin seem reasonable to get the latch, cups, and door card to line up.

[tsingson]

Are you completely removing the vapor barrier? What would work best for the black goo?

[kung fu jesus]

no, the barrier stays. what works best for it is not to touch it. :)

[HarryB]

The black goo is butyl tape FYI. You can find some decent stuff locally in hardware stores; if not look at companies with composite material supplies. Similar tapes are usually used to seal vacuum bags on composite manufacturing, usually they are much higher quality and tolerate higher temperatures without creating a mess.

[Demon I Am]

I did not, but would love to see this come to fruition. That's what I was thinking, was that most of the parts would need to be swapped. Have any nb2 friends that would let you take apart their door for a test fit?

[kung fu jesus]

I do, I just need to work it out.

[kevinharrop]

Possibly a stupid question, but why would you want to?

Why not buy a NB2 and be done with it?

Seems a lot of trouble to me.

[kung fu jesus]

There are distinct differences between an NB1 and and NB2 that have positives and negatives. The doorcards on the NB2 have a different design that are beneficial for modification, and are a little slimmer.

[kung fu jesus]

Bumping this one up. I have been slowly acquiring the parts I think make this change a bit easier.

I have the NB2 door latch mechanisms that have the cables versus the NB1 rod-style.

I also noticed that the interior door release handles appear to be the same.

I hope to have some sort of process to share about this in the near future.

[lifebyevan]

Wow I didn't realize this was such an involved process. I thought the door cards would be a very easy swap and everything would line up. I was thinking about doing this for my NB1 and switch to NB2 door cards just for the aesthetics (Mainly the perforated patch by the door handle) but this is definitely making my rethink that. I might just clean up my NB1 door cards and call it a day.

[kung fu jesus]

I can tell you a few things about this swap. I have been negligent of going back to take pictures of this.

To me, swapping out the latch mechanisms to NB2 probably made this swap easier. They bolted right in and the units I attained still had the plastic cable captures that I was able to use on existing holes in my NB1 door. I couldn't imagine the fiddling of the NB1 door actuating rods would need to make this work. Apparently using the NB2 cable latching mechanisms are a popular upgrade for Miata racecars when the doors are gutted. It makes sense because the cables are easier to manipulate and place than the NB1 rods.

NB1 latching mech (without interior pull)
22125
NB2 door latching mech
22126
Approximating where the inner latch needs to attach
22131
NB2 latching mech installed in NB1 door
22123
NB2 interior pull
22124

I needed to test fit the NB2 cards a few times to mark the new mounting locations for the interior latch handle and the door card. For the latch handle, it was a number if little cuts and trimming with a dremel and cutting wheel. This is probably the most fiddly part because of the existing holes in the door and being careful not to cut away too much material.

Marking and trimming inner door skin to mount NB2 inner pull
22127
NB2 inner pull mounted on my NB1 door
22128

Marking the new locations for the door card screws is actually pretty easy. I hung the nb2 card on my door, put a sharpie pen through the nb2 door card screw holes to mark where they hit the inner door, removed the card. I made pilot holes, then slightly larger holes, reinstalled the door cards, tested that the screws landed in these new holes. I then took the cards back off, cut tiny 1/4" holes centered at these new holes with a dremel. These square holes allowed me to move and reuse the plastic anchors the NB1 door cards screwed into. With out these, it would be likely the screws could easily pull out of the thin sheet metal of the inner door skin.

Marking new door card attachment screw locations (difficult to see)
22129

The new inner latch handle doesn't sit flush to the NB2 door cards. This is pretty well-mentioned in other stories of this swap. The inner door skins of the NB1 do not have the recess stamped into them. I though about a hammer and dolly, but was able to used shims (washers) to make them acceptable. I also trimmed the back of the plastic door cup to help with this.

Shaving off the plastic on the back of the cup, first attempt
22130

The lowest pushpin on the driver's door, on the tailing edge when the door is open, doesn't match to the anchor on the door. I just made a simple L bracket and attached it to the inner skin, drilled a matching hole.

If you have long legs, you may find the NB2 cards a little unusual at first because the door pull/armrest extends farther forward, especially if you tend to rest your left foot (LHD car) on the floor, knee bent. Also, swapping to NB2 door mechanisms disables the auto-locking feature (iow, when you lock the driver door, the passenger door also locks). The wiring is similar, but I haven't gone in to correct it. I have looked at the NB1 and NB2 door lock schematics and see the differences, I *might* have a fix for that to work with the NB2 door lock thumb switch on the armrest, but it hasn't been a huge priority for me.

The NB2 mech physically plus into the wire harness, but is missing a wire, This may need a spice to connect to the thumb switch of the NB2 card.
22132

So, basically, if you want to swap the NB2 cards to an NB1, figure on 2-4 hours per side, depending on your skill and level of detail. I like the look, it completes the interior I did. I also considered doing custom NB1 door cards instead.

[kung fu jesus]

The door panels installed:

22133

22134

22135

22136

22137

22138

[MaRcOp01o]

They look great! I love your interior.

[HarryB]

Admire your patience, but at that point I would most probably look into swapping complete NB2 doors

[kung fu jesus]

Admire your patience, but at that point I would most probably look into swapping complete NB2 doors

If the colors were the same, for sure. Chaste White is an NA8/NB1 color.

[Hyper]

I think I have a twin brother