MZR DISI Turbo Swap: Can It Be Done?
 

My '94 1.8L turbo miata, fun as it is, is on its last legs. The lifters are ticking themselves into oblivion, the transmission makes all kinds of exciting clangs and grindies, the fuel pump is shot, the crank nose wobbles, and I can't drive when it's hotter than 80 degrees out or I get vapor lock. However, it's just such a great car that I can't get rid of it. My buddy drives a Mazdaspeed 3, and we both love it the way it pulls, but it's awfully heavy, and it has all this ridiculous practicality...

So here's the plan: take the 2.3L mzr turbo motor out of a mazdaspeed3 or cx7, bolt on a 6 speed out of a new miata, find myself a torsen and a custom driveshaft, and I ought to be one reflash away from a 300hp, 300ftlb speed demon.

The questions are: Will the new miata transmissions bolt onto the mzr turbo? Don't they put the mzr block in the miata now? Will the assembly fit in my car? Is the mzr internally balanced? Will the torsen out of a '94 miata withstand the torque? Where can I get this hardware anyway? I'm excited; it should end up being very subtle and very fast. Thoughts?

anything is possible. i dont recall seeing anything like that done before but why dont you just go with a v8 swap?

Anything can be done, but being the first to do it generally involves either a lot of work or $$$ or both
it would be far easier to build a 300hp turbo from an existing 1.8 or drop a Ls1/2/3 chevy small block in to get equal or better levels of power and the kits already exist to do both of these for less work and probably less $.

Well, the nice thing about swapping in a mazda engine is that they're light, they're fuel efficient, they're reliable, they're small, my mechanic knows them much better than he knows american v8s, and it'd be much easier to slip by california's fascist emissions laws. How much does a v8 conversion cost, anyway? It can't be cheap.

I will guarantee you an LS1 swap would end up being cheaper by the time you're all done. The MZR doesn't even share intake/exhaust orientation with the BP (intake manifold is on the driver's side).

agreed. if you dont want to do v8 swap, i can sell you my built 2.0L high-compression motor w/ aem ecu, 6 speed tranny, kaaz rear end, etc so i can go v8 :)

I thought most engines rotated the wrong way for a miata diff and transmission, ie you might have 1 forward gear and 6 reverses. Anyways this conversion, although theoretically possible, would cost quite a bit once you buy the engine and supporting parts (turbo, manifolds, wiring harness, ecu, etc). The issues with your current miata add up to about $2500, if you buy a built motor and either a 5 or 6 speed transmission out of an NB (for strength). If you just buy a JDM replacement engine and a used transmission, you're around $1500, if you don't want to fix your engine at all. A rebuild can be a fun and exciting learning process.

or he can buy my shit so i can go v8 (yes, im going to insist on it)

That's a good fucking deal right there :hustler:

you bet. its all complete too! just plug and play. ill even throw in my custom itb setup when its done ;)

The MZR swap is my dream swap. I hear a miata cyl head flows better than the Mazda 3 head. Does anyone know it they use a Miata head on the Mazdaspeed 3?

Oh yeah! you're the anti-v8 guy.


LSx is the best period.



LSx > anything you can drop in a miata

Swapping anything except an LSx into these cars is moronic. Either build and turbo the BP, and get 300+whp out of a decent setup, or swap the LS and do 400-500. Spending the time and money and effort to do an F20c swap or an SR20DET swap is useless - you end up with the same power as the BP for waaay more money.

I learned my lesson about speaking without thinking. That is a swap I am thinking of doing.

Lol I remember the days when I thought swaping a 13btt or a s2000 engine into a miata was the shit!! :laugh::laugh: :bang:

I think that it may end up being a popular swap. Once it has been done, and parts have been developed to do it, why not? I see it using current miata motor, trans and rearend. An advanced swap would be to use the block out of a Mazda 3 for the extra cubes.

Just when I thought you got it ... :facepalm:
I just not worth it.... :dunno:

:skid::skid:Give it time. You will see.

If you are absolutely dead set on swapping an MZR into your Miata, then do it. It hasn't been done before, so everything is going to have to be fabbed up. I hope you have a lot of money, or a lot of fabrication skills. Don't take this the wrong way, but judging from you asking about this swap, it seems as if you don't have the skills to do this swap on your own. Be prepared to spend a ton of money, as all the hours of labor and parts are going to add up quick. In my humble opinion, I agree with everyone here that a turbo BP or an LSx will get you the same/more power than from an MZR for a lot less money.

I know that it will be a lot more expensive than a V8 swap at first. And you are right that a lot of fab work will go with it.

I am not financialy in the position to do it right now. It is still a dream. I do however, have some fabrication and race car building experience. I have done a few DIY projects on my car. And I am not talking about buying and installing parts, but actually building them. The projects that I have done are not near as complicated as this type of project, but I am working towards that level of difficulty.