It's been talked about forever and ever and Here they are, adapter plates to put a TII transmission onto a miata motor. TII transmissions are significantly larger than stock miata boxes and are documented to hold well into the 400-500whp range. I broke 2 miata transmissions with 200whp.




CAD Designed, CNC machined, made in the U.S.A. Plates are laser scanned and converted into solid works and CNC machined for a quality, final product.



$450 SHIPPED in the CONUS with the plate and hardware you need (Plate to motor, trans to plate, and starter.)













Stock miata parts used:

miata slave cylinder, throw out bearing, pilot bearing, 5 speed starter

What you need to buy:

NC miata clutch disc. (1.8L clutch/flywheel only)
(replacement discs are CHEAP)

Turbo II transmission

Custom Driveshaft (I recommend Shaftmasters (aluminum) but local driveshaft shops are usually capable)

What you need to make/modify:

Space out stock FC clutch fork with 2 washers (make up for plate thickness)

PPF solution
(Differential mount/transmission mount, Adapting Trans to accept PPF)
(several roadster owners have documented solutions to this problem already)

Notch V shape in bellhousing to accept miata starter




Not for dog box transmissions, do not put plate on your dog





PM me with any questions, inquiries, or if you just want to buy this and stop worrying about transmissions.

 

I was under the impression that you could put the Miata bellhousing on the TII box and you wouldnt need an adapter plate, but I must be misinformed

Very nice work

 

NA FC (aka a miata transmission) not TII

 

Lol.

GLWS(s)

 

If I didn't already buy my clutch I might be interested.
GLWS

 

Nice part. Good to see you made some for others...I wish I did not sell my TII trans.

 

You'll need to cut off the starter portion of the TII bellhousing because of the lack of exhaust / downpipe clearance in the miata.
The RX-7 TII slave will fit without having to cut into the miata frame rail as you do if you keep the stock slave.

 

Why would a stock slave interfere with the frame? It's on top of the bell housing

 

Near the bottom of the page.
TII tranny into Miata!!

The bleed nipple on the Miata slave points to the left of the engine bay while the RX-7 slave points up.

 

Pretty good stuff! It is a bit on the steep side as far as pricing though. Doesn't look like you have any dowels for the plate to transmission side, is that correct?

 

What did YOU do for the PPF? This swap does interest me, as the TII tranny gives me gearing I like when used with the 3.9 rear end.

 

^ Same question. I have seen some use a cut PPF that bolts to the trunk floor. My question is, how's the center console and shift boot after all this? Does it look stretched in 2-4-R?

How many of these things you got?

 

I didn't. All the pics in the link above are your best bet.

I would get rid of the ppf altogether and run a trans/diff mount

 

Nice man glad to see you finally got them done!! They came out great.

It's prob close to $100 in raw materials alone, plus the design work, machining, gathering the hardware, etc etc. I think the price is more than fair.

I ditched mine. It's easy enough to just fab new trans/diff mounts. RX7/miata have the PPF/exhaust on opposite sides of the transmission from one another.

The cut PPF you are referring to is for the diff mount, not the trans. THere are a variety of options available for the diff mount out there.

Concerning the shifting, when I shift into 2, 4, R, the miata boot is a little tight, but it doesn't interfere with shifting. I didn't have to modify the console at all. A keen eye can tell it isn't centered in the console opening, but it never bothered me. Shifter placement, at least for me is also right where I'd like it, ergonomically speaking.

 

No one has bought a single one. Kind of surprised

 

I will buy one once I have a better handle on my finances (head work to get the car running and paying off my Daily Driver come first). I for one am not too keen on pulling my transmission every time I go have some fun and shear off gears lol...

 

Im about to ask if i can buy my RX7 back.... the trans was in great shape, and im sure i can sell the shell for what i buy it back for...
if i can, im definitely game

 

I'd be interested at about $100 lower price point.

Just being honest, maybe that's why you haven't sold any.

Everyone here is cheap, and $450 is more than half way to a 6 speed which seems to be an easier way around the issue...

 

I know there are people who have broken 6-speeds due to too much power/not enough empathy. But they are few and far between. And the one I know apparently sold his before getting it on the dyno.

 

All Plates and hardware are ready to ship! Only 4 left!