Fresh NA6 Owner in over my head...
 

Hello MiataTurbo,

I am 25 years old, and living near St. Cloud, MN. I am as green to turning wrenches as I am to MiataTurbo, but work as a service writer. My position happens to provide me with access to lifts, endless tools and equipment, and most importantly co-workers who are proficient technicians that are also willing to help me. I have been developing a passion for cars and motorsport over the last 4 or 5 years. I have spent a great deal of time driving in simulations with a force-feedback wheel and 3 pedal set, and yet have very little real world experience with a manual transmission (having never myself owned a vehicle equipped with one). As such, I have wanted to buy a cheap car with a manual transmission for quite some time. I just want to get some more seat time. I am not trying to race, or even to go particularly fast. I just enjoy the drive and want to improve my rapport with the road.

To Craigslist I went searching, but searching for what? I figured that if I am going to do this then I may as well try to find the best driving experience I can get for my dollar. I knew I didn't want front wheel drive. AWD was definitely considered, but I much prefer the dynamics of a RWD vehicle. I weighed all the pros and cons of different cars in my price range, ultimately narrowing it down to the Miata (or maybe an MR2 if I found the right deal).

Living in the so called "rust-belt" I had a hard time finding a solid foundation from which to begin my Miata adventure. Clean cars hold a lot more value here and I didn't really care to pay a premium for that type of starting point. However, my brother lives on the west coast. So my search slowly transitioned from looking for cars here to looking for cars in his area, and I have underground parking with which to store a rust free vehicle in the winter. This leads us to the blue belle in my sig. The only problem is that she's an automatic. Somewhere along the way I had become so enamored by the rust free shell and paint matched hardtop (oh, and the price I suppose) that I had forgotten my original intention of finding a proper machine that would help improve my connection to the road. In any case I had already pulled the trigger and purchased the car. Doing some more research I am kicking myself for not holding out and finding an equally pristine manual. Not so much because the swap cannot be done but because it is not a process that is as well documented as I had hoped. At the same time I have always been one for puzzles, so I do still endeavor to take this challenge on.

Despite the impressive amount of combined experience in my shop, nobody there has any personal experience with the Miata. Which has led me to MiataTurbo. In particular one question has been burning in my mind over the last day or two and I cannot seem to find an answer. The question stems from the Flyin'Miata "Swap Hints" Instructions where it states: "But wait! You have a complete donor car, so you can just use the 1.8 ECU and wiring, right? Nope. Sure, it’s possible, but it’s going to make your life dramatically more complicated for little, if any, benefit." This single sentence has led me to believe that my intentions in this process may be much more difficult than other guides have made it seem.

I am hoping I have found my own answer to this question, and that is that this concern will not apply to me If I swap the motor, transmission, wiring, and ECU from the NA8. My understanding is that the caution provided here by FM is because their guide is to swap only the engine, as they assume one to be starting with a manual. I have read similar concerns in transmission swap guides that a basic transmission swap is quite a bit more than people anticipate because the whole harness has to be done as well. My understanding now is that I can take everything from a NA8 donor (PPF, 1.8L, Manual Transmission, Wiring and ECU, drive shaft and rear end) and more or less bolt it into the NA6 shell). Perhaps brakes and suspension as well unless I go with my plan and decide to upgrade those things altogether. I do question now however if my intentions with the vehicle will lead my to a place where I would need to take the NA8 dash as well what I listed above if some of those connectors are required.

As you can tell I am in way over my head. But the reality is I am getting way ahead of myself. Really, I am just a new NA6 automatic owner kicking himself for not waiting to find the right deal on what would make me a new NA8 manual owner. Still I got a great deal on this thing and will probably be able to make this happen for the same as what the average manual in this shape would cost in my area, but only if I can do most of the labor myself (or with friends). I do enjoy projects and hope this is something fun to do with my friends over the winter.

That is my story. That is why I am here. I jumped the gun and bought a very clean NA6 automatic with the intention of swapping in NA8 everything else from a manual donor car. I am hoping you all can help in the process, or at the very least enjoy in the successes and failures (presumably mostly failures) as I document this process going forward.

Thanks,
Sage

I would break your swap into several pieces. First I would swap out the auto for a manual transmission. Mate the manual to the stock 1.6 motor. There are lots of guides/posts on miata.net that should cover the auto to manual swap. Then I would swap to the 1.8 rear end. There should be no major wiring changes needed to do those 2 swaps. Then after those work on swapping in the 1.8 motor.

Sorry douple post

Does anyone modify the automatic transmissions here, or do they just throw them away?

Here's another thought.

If clean, rust-free cars command a premium in your area, why not just resell your car at a profit from what you paid for it, and then restart the search for the right car -- a '94-95 NA?

^ or an NB

Or that, depending on emissions laws in your area.

^ catfish

Done
 

https://cimg5.ibsrv.net/gimg/www.mia...f5f4805107.jpg
https://cimg1.ibsrv.net/gimg/www.mia...c476763970.jpg
https://cimg3.ibsrv.net/gimg/www.mia...84a51c3508.jpg

I swapped in a 6 speed and 3.9 rear end. It was about as smooth an operation as it could get. I did not end up having access to lifts at work and still got it done in about 20hrs over 3 weekends (one workday per weekend). This was mostly just my one buddy and I with an occasional 3rd man. The car is running very well, and doesn't even throw codes because I left the PCM and TCM alone.

https://cimg9.ibsrv.net/gimg/www.mia...b20c32e19a.jpg


I am still running the auto 1.6 motor unmodified, and have a 1.8 BP4W torn down to the block that I may not use (if anyone is interested). Feels like more work than it is worth right now. Going to work on suspension while I decide where to go for the power, but I am mostly building with a K24 swap in mind as the eventual goal.
https://cimg4.ibsrv.net/gimg/www.mia...f08e30b10b.jpg

I did drive the 6 speed with the stock shifter, in early test runs, before installing a Miata Roadster short shift kit. I will add my voice to the chorus of all the others who sing praise of what it does to the shift feel of the the 6 speed. I can't comment on the feel of a 5 speed, stock or otherwise as I've not tried them.

https://cimg7.ibsrv.net/gimg/www.mia...5467a071e4.jpg


In response to Last man standing:
I've not seen anyone with a built automatic, but one of my coworkers suggested it early on as sort of a drag application. The one I pulled out of the car was rebuilt by the PO (for like $2800!!!?!), but I don't think that was a performance rebuild in any way, that was just to rebuild it back to stock.

Some folks have built auto trannies, I think there's one for sale in the classified section.

Nice, that was a refreshing read. You started out not knowing what you were getting into now you've got a 6-speed NA. Badass!

thats awesome you did the swap!

With a 3.9 torsen :skid:

Yeah. I mean I had never changed oil before haha.

Thanks guys. Yeah it was a blast. I had a lot of fun with the car in the months leading up to the swap, but it is so much more fun now. I am in love.

949 Big Grip Kit showed up at work yesterday too :bowrofl:

It is all sex... pure sex.

Xidas, Sway bars, and end links are in
 

https://cimg1.ibsrv.net/gimg/www.mia...0a97a9eff7.jpg

I need to play with the ride height and damping still, but what an improvement in ride quality, comfort, and performance. Can't wait for new shoes.

Nice job man! dont be intimidated to turn the damper adjustment in the stiff direction. You will be surprised at how comfy the ride gets, depending on springs used of course. After a bunch of testing, I ended up a bit further into the damper than I figured I would be. Suspension set up is not intuitive. not to me anyway.