NB to NA full suspension & drivetrain transplant feasibility

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thehillsarecalling
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NB to NA full suspension & drivetrain transplant feasibility

Postby thehillsarecalling » Wed Dec 11, 2013 1:33 pm

Hi all,

Firstly, yes I did Google. No I didn't find an authoritative answer. Yes I'm sure this has been done before, so there is an answer out there somewhere, hence this post :).

Situation:

I have a 91 NA6 and a slightly smashed 98 NB8A. The NA running gear is ok, but the brakes, suspension bushings etc are all getting pretty tired. 22 years tired :).

What I am planning to do is migrate the entire running & rolling gear from the NB to the NA. I could lift out the engine & trans, pull the front & rear subframes, and migrate them over in a 3 piece job, however what I'm thinking is to unbolt the subframes, various wiring bits, steering rack, speedo cable (on NA), engine ancillaries etc, and then lift the NA body off it's tired subframe / drivetrain, then lift it onto the NB subframes / DT.

This thread (and more importantly picture), makes me believe that it would be possible with a bit of mucking around.

http://forum.miata.net/vb/showthread.php?t=451450

And this photo (and the one before it), makes me believe that it is 100% possible

http://www.flyinmiata.com/V8/CF-55/index.php?UID=8

Questions:

Questions I have thought up. I'm not expecting answers to the more technical ones, there's Google for that, but I would like comments on questions 1 & 2.

Most Important wanting feedback on:
1) All in all, would this save time versus migrating things in 3 parts?
2) What gotchas / headaches are to be anticipated?

Can figure out by myself, but feel free to add something if you want:
3) What works should be done while the car is separated from it's subframes? Cleaning out the engine bay seems like a nifty idea
4) Are there any clearance issues dropping the engine down instead of pulling it up?
5) How much rise would the body need in order to enable the subframe to wheel out from under it? I would estimate about 1.2 - 1.5m? I suppose I could figure this out by measuring the highest point of the engine while it's still in the car...
6) How compatible are the wiring looms? I have a MS2 for engine management, so I won't be bringing across the ECU / immobiliser from the NB. Would it be quicker to take the wiring looms with rather than disconnecting & reconnecting?
7) Will I have issues with ride height afterwards due to the NB suspension being longer than the NA? Understand about switching top hats - would it be more appropriate to use the NA or NB top hats based on the NB subframes / assembly & aftermarket suspension into a NA frame?
8) Does the tomato go under the cheese or on top of the cheese in a toasted cheese and tomato sandwich?
9) How difficult will it be to line up 2x subframes while the car is hovering above them?
10) Are brake line fittings and master cyl assembly compatible with the larger NB brakes?
11) What exhaust issues am I going to run into? Do I take the stock header from the NB then work in the NA exhaust, or do I need to get a custom exhaust (am aware the NB exh does not fit the NA).
12) The NA currently has AC, but no PS. The NB has both PS & AC. The NA runs the older R12, while the NB runs the newer R134a. Can I bolt the NA compressor to the NB motor, or will I need to futz around with a full AC transplant as well (I understand that the compressors are incompatible with the different gas types).

Reward:

Reward? If the consensus is that it's not impossible, and quicker to do than individual subframe & engine migrating, then I promise to document the process on the forum so that the next bozo with the same silly idea as I can get a heads up before they hit the spanners.
Daily: '91 Malibu - NB8B conversion, 6sp, Teins, Whitelines
Terribly Missed: '02 Black SP (#55)
Plus about 12 others over the years..

Apu
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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby Apu » Wed Dec 11, 2013 1:41 pm

Look up Lightyear's thread. He's done the swap.

spikes
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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby spikes » Wed Dec 11, 2013 4:25 pm

Your googling skills sucks :p

spikes
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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby spikes » Wed Dec 11, 2013 5:05 pm


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davekmoore
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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby davekmoore » Wed Dec 11, 2013 7:37 pm

UK since return: Standard NC2 (horrid), C200K, ND2 BBR, NC2 BBR200 (loved it), NC BBR300 (better than BARMY), V-Special, turbo NB8B (my 84th car)

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zossy1
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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby zossy1 » Wed Dec 11, 2013 9:40 pm

Yep, Dave Lightyear's car is even more extreme a swap than the one you're suggesting. He did an NB8B into an NA6, which included ABS and the VVT power plant plus the 6 speed. Yours is a bit simpler. Reasonably easy if you have the facilities but VERY time consuming to do a complete transplant.

thehillsarecalling
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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby thehillsarecalling » Wed Dec 11, 2013 10:20 pm

Hi all,

Ok have established a few things:

1) My Googling needs the upgrading. After getting home from work and doing some actual research (ie not lunchtime idle speculation and first gear low RPM googling), I have established that 95% of the questions above have already been answered.

2) It's possible, and not super hard.

3) Instead of thinking about how to unbolt stuff, I should be thinking about how to architect the lifting apparatus, as that will be more tricky as I don't have a hoist.

4) Lightyear should open his own shop and have a rich uncle to fund all his projects.

5) Cheese goes on the top

6) Youtube has some ok videos to follow

Thanks for the posts guys.
Daily: '91 Malibu - NB8B conversion, 6sp, Teins, Whitelines
Terribly Missed: '02 Black SP (#55)
Plus about 12 others over the years..

sailaholic
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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby sailaholic » Thu Dec 12, 2013 6:43 am

I can say a fork lift works well for lifting.


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Re: NB to NA full suspension & drivetrain transplant feasibi

Postby Boyracer » Tue Dec 17, 2013 10:42 am

The only thing on this car that is NA is the body.

viewtopic.php?f=57&t=55888
NC Roadie, NC Racey, ND Racey….and a 30AE

Plus several others in the bone yard...


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