Official Transmission Swap Information (Update 21/05/2010)

[Ryan]

The thing I was going off of was....

In the 93 workshop manual, there is both the SOHC and DOHC RS. All DOHC's are OBDII, right? So therefore I think that the cross over started in mid 93....

[wytbishop]

I don't believe that all DOHC's are OBD2. I think that 94's and early 95's are OBD1. I can't confirm it but as I said so many people told me that my 95' RS had to be OBD1 because the change was mandated for the 96' model year.

from Wiki:

~1994: Motivated by a desire for a state-wide emissions testing program, the CARB issues the OBD-II specification and mandates that it be adopted for all cars sold in California starting in model year 1996 (see CCR Title 13 Section 1968.1 and 40 CFR Part 86 Section 86.094). The DTCs and connector suggested by the SAE are incorporated into this specification.
1996: The OBD-II specification is made mandatory for all cars sold in the United States.


Mazda could not have begun in 93' because CARB had not yet made the announcement.

[Ryan]

Hm, See, thats the perfect kind of input, exactly what I'm looking for. I'll edit accordingly...

[GringoEJS]

Ryan, I just thought that I would let you know that this weekend I put a 95 Protege 1.5L Automatic Transmission into our 94 DOHC 4 cyl 1.6L MX-3. I used the Protege torque converter, had to swap the speed sensor (which unless you grind the edge, you won't get the 10mm to bolt it securely, but since it is such a tight fit anyway, I am pretty sure it won't pop out), also had to remove 2 14mm bolts from the Protege tranny to put the rear mount bracket, but it is obvious and a direct fit. Overall it was an easy swap. The tranny shifts great, and this might be useful for anyone needing a hard to find and even expensive DOHC MX-3 automatic tranny where the Protege is far more common and therefore cheaper.

[Ryan]

This is still going... I wish people like Yoda could spend 5 minutes here

I'll go look for the specs on the 1.5 auto.

[MX-3.com]

Great thread Ryan,

Let me know when this post becomes finalized and we can movce it to the FAQ.

Thanks,

[seawulff]

i am putting a dohc 1.8l 4cyl from an excort in my mx3 for now while i build a turbo 1.6 for it. as far as transmissions go, i am curious if anyone knows anything about other trans that will bolt to the b series engines. i read somewhere that the Kia sophia trans is a stronger build than the f5m-r that is bolted to it in most mazdas. not sure the validity to this.

also in my ascociats and i's future we are planning on building a mid engine rear wheel drive mx3. surprisingly not to difficult. i was curious what anyone knew about rwd trans that bolt to kl series engines. i know miata has some rwd trans and rear ends but i dont realy know the details.

[Ryan]

You're going to be disappointed.


A B series motors bolt to eachothers trannies. The BP trannies are the strongest.

There are no K series RWD cars.

1st gen Miata ran a BP/B6 and its tranny will bolt to a BP/B6.

[Chris_W_2k5]

I have a 95 RS that I want to use for circle track racing, and was wondering if putting a trans from a V6 would be a good idea or even possible. Are they easily swappable or do they mount completely different?

[Ryan]

You know, this thread is entirely useless because people STILL DON'T READ IT!

No, the bell housings are different, obviously. Although the innards interchange. If you look through the gear ratios, and know what you need for your application, then you can do whatever you'd like.

You've most likley got an F25M-R in that badboy. A general G series swap will do you good as that tranny was more designed for racing.

[wytbishop]

Agreed. Get Mooneggs to delete the off topic posts (including this one) and get this train back on the rails.

[cricketol2]

is there a way to change the gear change the gear ratios like use a miata gear system in a f series trans or even a g series would bo ok with me i just dont like the gear ratios of any of them ..

[Ryan]

Read man... ALL GUTS BETWEEN F'S INTERCHANGE, AND ALL GUTS BETWEEN G's INTERCHANGE, and there is specualtion about some newer Ford gearboxes.

[cricketol2]

even with the miata trans?

[Ryan]

Miata is RWD man, nothing like our FWD cars. Does the RX7 tranny bolt up? just as stupid of a question.