I will try my best to explain the two methods i have been using to make Z32,Z33 and RB25 gearboxes fit CA and SR engines.

The reason why i use Nissan gearboxes are because they use the same spline, so you can still use the same clutch.
They have ratios that match the diff pretty well and they are cheap new.

How much the input shaft sticks out over the flange is what is cruicial, the shafts are all the same but the amount of "stick out" is different.
CA/SR = 18mm
Z32/RB26 = 16mm
Z33 = 12mm

I aim to get the "stick out" same as it is stock on a SR/CA transmission.
It`s better to have 1mm shorter shaft vs 1mm too long.

For that reason i always make the housing a couple of mm too long before welding.
Then i can machine it down to the correct length.

For alignment it`s a good idea to bolt it to a block, vertically.
There is also a cast seam on the top of the gearbox and the flange wich needs to match to get the orientation correct.

Method number 1:


This is how i did it on a RB25 gearbox:

Ca flange over the RB housing:



Cut the RB flange of:



Machine the housing:



Mount the finished machined CA flange to the centering device :



Tack welding it:



Finished welding and is going to be machined again (warps when welding):



Finished:



Mounted in car:




Method number 2:

This one is a little more advanced, its the same when cutting and machining the housing, but instead of welding on a flange from a donor box i use a blank watercut flange and machine the bolt-pattern and guides after the welding is done.
The flanges are cut with a groove to match the cast seam on the gearbox.
It`s a more accurate but also more complicated method.


Here`s a photo of the watercut blank flanges, its made in pieces to save material and are bolted together to the guide plates shown.
These bolt holes miss the stock bolt-pattern and is not used after welding.



The "guide rod" wich centers the blank flange is shown here:



Here`s a photo of some housings welded but not machined:



Machining:



Machined:





I have probably missed several things, please feel free to ask.

Also excuse the quality of the photos and all the SR realted photos, they are the ones i have the most pictures of.

wow.

Nice!!!

How much you charge? lol

Are you selling these? With shipping?

This looks great, nice work!

Not really questioning you here, and there's no doubt the Nissan trannies are very stout, but is still being able to use the same clutch a viable reason to use a Nissan tranny? Don't get me wrong, I'd love to have a Z32 trans on a CA, but if you're making enough power to need a Z32 trans then being able to use a CA specific clutch is irrelevant since most of them couldn't hold that power. Lol, just making an observation.

Any advantage to this over going with a Mazworx kit? (I haven't really looked into the Mazworx kit, just know it's an option)

float_6969 wrote:Nice!!!

Thanks!

sjbsuperman1425 wrote:How much you charge? lol

If this is interessting you can PM me but i think shipping would kill it all.

Izento wrote:Are you selling these? With shipping?

Same answer as above, i do make these for others also

mdb4879 wrote:This looks great, nice work!

Not really questioning you here, and there's no doubt the Nissan trannies are very stout, but is still being able to use the same clutch a viable reason to use a Nissan tranny? Don't get me wrong, I'd love to have a Z32 trans on a CA, but if you're making enough power to need a Z32 trans then being able to use a CA specific clutch is irrelevant since most of them couldn't hold that power. Lol, just making an observation.

Any advantage to this over going with a Mazworx kit? (I haven't really looked into the Mazworx kit, just know it's an option)

Ask all you want, and give me your opinions

The clutch argument is just a nice bonus, but also a big time/work saver considering other alternatives where the carrier bearing inside the crank has another diameter.

The ratios are the biggest selling point i think, if you have a high powered streetcar, z32 tranny is a nice match.
If you have a moderate powered street or track car a z33 transmission might suit you better.

They are also both pretty cheap to buy brand new.

I`m not a big fan of adapter plates, housing needs to be machined anyways and you often dont get to use all the bolts or can even access them.
I have no experience with the mazworx adapter plates, just a general statement.
They supply a driveshaft that`s not even safe with the adapter plates, i dont like that.
The accuracy is another concern, an adapter plate can be made very good and not so good.
Method 1 here is the least accurate but i have made 5 boxes this waywithout issues.
Method 2 is as good as you will get it, the machine used to "blueprint" the stock housing have no troubles measuring 0.001mm.

You get single plate bolt-on clutches that holds close to 800nm, i myself have Tilton twin plate which holds 1200nm.

cool thread

what did you use to cut off the flanges in the first method ?

how much are these "cheap" gearboxes, brand new ?

as far as CA clutch torque holding capacity, one can check out what the 'torquey' turbo ka24de guys are using
All depends on "how" you treat the box also..... seeing as street 240sx done 10 sec 1/4 mile on stock ca/sr/ka box

rb box looks a lot stouter and heavier than a ca/sr box. I wonder how older BMW 5spd boxes compare....
as I recal some european hot ca18 guys claimed thay ran adapted bmw boxes and clutch

I think Mobne is either running or planning on running a 6 speed from an E46 M3

I use an angle grinder and then machine the surfaces parallel.

The problem with BMW boxes are (at least the 5 speed) that the ratios is way off.
Very short ratio`s and 1:1 ratio in 5th.

6 Speed BMW boxes are not cheap, have an OK ratio in 6th but have a bigger diameter shaft bearing.
The price for a nice but USED BMW 6 speed is often higher than a brand new Nissan transmission, atleast here.
Z1motorsports.com has both Z32 and Z33 boxes.

yeah, we use angle grinder as well

another box worth looking into may be the 5 spd from the rx7 turbo II
some folks use them behind powerful mitsubishi 4g63(2.0L) & 4g64(2.4L) street cars
Back in the mid 90s I witnessed a full weight street Turbo II rx7 click of a string of 9.6 sec 1/4 mile ETs!
Even had a smooth idle (no heavy porting/brap-brap) Impressive to say the least.
That box is physically about the same size as the ca/sr/ka 5sp

I have no experience with those transmissions, but i have heard that they are good.
Probably cheap also.

mdb4879 wrote:I think Mobne is either running or planning on running a 6 speed from an E46 M3

Yes Mobne is running a 6 speed BMW Getrag s6s-420g i belive.
Probalby not the best option if you are looking for grip, short ratios equal tire smoke on a high powered car.

- S14 stock -------------z32-------------getrag s6s-420g-------------2JZ-GTE V160 6-Spd
1. : 3.321 -------------3.21---------------- 4,23 -------------------------- 3.827
2. : 1.902 -------------1.93---------------- 2,51- ------------------------- 2.360
3. : 1.308 -------------1.30---------------- 1,67--------------------------- 1.685
4. : 1.000 -------------1.00---------------- 1,23- ------------------------- 1.312
5. : 0.838 -------------0.75 --------------- 1.000- ------------------------- 1.000
6. : - NA ---------------------------------- 0,83 - ------------------------- 0.793

So innovative Great job, man!

Thank you!