Swap NB 6-Speed Drivetrain into NA or Buy Cheap 6-Speed NB
 

I've been out of the Miata game for a few years with college and full-time job stuff yada yada.. So now I have a little more monies to play with and want to enjoy my Miata again instead of watch it get covered in dust while my STI gets daily and autox duty.

The key is I want to do it right and not cut corners like I regretably did in the past. In my eyes this means for longevity a 6-speed trans and matching 3.9 torsen are in order. Also, to make the most of the power-band, VVT would sure be nice now that tuning it isn't the hassle it use to be.

So as I'm looking at the costs of replacing the driveline (motor, trans, diff) and probably recreating the turbo setup with a more appropriately sized turbo, I began thinking. Does it make sense to buy a 5k or less 01+ 6-speed car instead of buying all the parts and swapping them into my non-torsen 5-speed car?

To those of you who have had both or had experience with both please share your input. This car would be have light street duty and mostly autox with track use possible in the future.

For reference:
Current Setup
100k mile BP
T3/T4E Journal Bearing
Log Mani with 2.5"/3" Exhaust
FM Link ECU
Fat Cat Coils
RB 1.1.25 FSB
16x8's with 225 Toyo R1R's

Future Setup
Built VVT motor
EFR 6258
Tubular Shorty (AbsurdFlow style)
MS3
Swap over Fat Cat's
New RB 1.125 FSB
6UL's with plenty of rubber

The NA is a cheaper shell. If you just want the parts, buy the parts. No sense in buying a damn car because you want $3000 worth of parts.

Whats the goal of this car? Auto-x? HPDE? Both? I'd stick with the lighter NA chassis. But if its an AX car you're gonna want to put a 3.63 R&P from mazda into the rear end with the 6 speed because the 3.9 just doesnt have the right gearing.

I love NB's. Hands down better car than NA for daily driver use.

Outside of daily driver use, just about everyone here seems to favor the NA.

I think a big consideration will be how much of the work you will realistically do yourself. The NB gets you closer to immediate gratification where the NA requires a lot more effort to get there.

Does it? Is putting in a tranny and diff a lot more work than swapping his turbo setup into a new chassis and engine?

he's not retaining his current setup

If I were to do it all over again, and could afford it, I would pick up a 01-02 with a 6-speed.

Engine + gearbox + differential swap in an NA seems like significantly more work than adding a turbo kit to the NB to me.

This is what I have been teetering toward.

The car will not be a daily, but I would like it to be streetable from time to time (think car shows, or driving to a local autox or track event). As I had mentioned I would like to be competitive in autox and at some point in the future it might see some hpde time while making 300+ comfortably.

Part of my hesitation to try and cobble all the parts together is my general mistrust of salvage yards. This wasn't helped when I drove 200 miles (one way) to pick up a 6spd and 3.9 diff that was shown pulled from the same car and upon further inspection is actually the 4.3 variant... I know, shame on me for not checking but I didn't have axles or a way to pull the case apart at the time of purchase. Hopefully I can get my money back out of it.

I appreciate all your opinions. It seems like everywhere I ask the group is mostly split down the middle which is what I was afraid of.

IF I choose to go the NB route, is there a mileage to be afraid of regarding the trans/diff (100k, 130k, 200k)? The motor will likely get internals so I'm less worried about that.

01-02 diffs are TORSEN brand T2
03+ diffs (except Mazdaspeed) are Tochigi-Fuji Super brand modern clutch-type units

Locally? Regionally? Nationally?

I don't keep up with cone killers as much, is there a class where the NB can really be competitive beyond a local level?

I know a well setup, well driven NC in STR can compete and win against the S2000s.

I think he means in ssm. Regionally really matters whos in your region. If strelnicks/Thompson are in your area you're fucked. But if there's no ssm cars with real aero and big hoosiers you'll have a chance.

I once had my ass handed to me by Strelnick...it was amazing.

Personally, I prefer the NB as well. For something I have to look at every day, it's just better looking inside and out IMHO. You can pick one up with the 6spd and sport suspension and "big" brakes...and you can sell some of that stuff easier to recover some costs as well. It is a bit heavier than NAs, but that can be taken care of. Not to mention the image NAs are getting now because of the lower cost allowing the retard stance and hellaghey crap to buy them :td:

so so very true.
some of the early NB's are starting to get to that point too now, but for the most part the 01+ is still "safe"

I saw an 04 listed for 6something last week (which is KBBish). I've seen NAs listed for more than that. At least in this neck of the woods. NAs are on the price rise and NBs are on the drop. I havent seen any NA8s listed for as cheap as I bought my R-package just a year ago. I'm thinking next year NAs will have come up in price and NBs come down enough that they'll be the same 5-7 grand range for an average car.

I picked up a 6 speed/3.9 torsen/driveshaft/axles from an 02 with 80k for $1500. A vvt motor will probably run me another $800 if I decide to do it. So 5k+ for a nice 01-02, or about 2.3k for the drivetrain. I chose the latter. Though going through all this trouble of swapping drivetrain, I would only want to do this on a 1.6 chasis as it's the lightest. Sure it's not the easiest route and you might get pissed at things for being rusted/stuck on a 20+ year old chasis but it's definitely a good way to familiarize yourself with the car.

'95 or earlier because no OBDII.