I have the old 5 speed out of my '92 I can measure and draw up at work. The trans is in storage at my brother's house; I should be picking it up sometime this week.

Awesome!

Out of curiosity, how do you do it? Put in pegs and measure the separation of the dowels? I've done that, too, but again, never feel good about it.

Pegs in dowel holes?

We have a Faro arm at work for digitizing stuff. I'll just put the trans on a table, make the bellhousing face a plane, and pick up the mounting hole locations, dowels, input shaft, and outer profile.

=o

turbotim, it sounds like you're about to become my hero, lol

let us know how it turns out :)

Sigh, I figured you'd cheat like that.

You CAN put dowels (or screws) in each hole, measure the distance from the outside of one to the outside of the other, subtract one bolt diameter from it, that's the distance between them. Do it for every pair, sit down for a nice long day of math (or use a constraint based CAD package) and get where they all go. But it's a huge pain, and more error prone.

High tech equipment for the win.

Here is a .dxf of the bellhousing of my '92 5 speed. It is the raw data from the Faro arm. Sorry, I do not have time to go thru and make it all pretty-like.

Let me know if you need any other info on this, I may have measured it.

Thanks to Paul for hosting this.

Tim

http://www.inoneear.com/outtheother/MazdaBPTrans.DXF

Couldn't one just use that metal seal that goes in between the motor and trans as a template? Tape that bitch against the desired piece, use a center punch of the appropriate size for each hole, and throw that on a mill or drill press with a vice.

But how thick is this piece going to be? How are you going to get the shaft depth right?

I had always thought of this as a very cheap V8 swap idea, if you had a low power v8 and were into such things...

tim, that's awesome, thank you!

i'll see if i can clean it up a bit and re post it.

now i just need to track down the same thing for the toyota bellhousing...


this piece is probably going to be 3/8" thick steel. depending on the trans you use your shaft depth may need to be corrected with a flywheel spacer. my plan is to cut up an old flywheel on a lathe if it comes down to that. if i leave enough of the old flywheel to center on the crank, and then find a precision sleeve to press into it, the flywheel should center just fine on that sleeve.

dead thread revival...

after TurboTim was kind enough to make this DXF for me, i was having a hell of a time getting someone to do the toyota bellhousing for a reasonable price. in the meantime i kept talking to people about this, and eventually found somone who's working on the same thing for his BPT powered 323 GTX rally car.

the best part... he works at a cnc machine shop in CA. he was able to use a CMM on the toyota bellhousing, and right now is working on combining the two patterns into a usable adapter plate! i'm just going to purchase the finished piece from him, rather than making my own. custom mounts should be no big deal, and i already have all the other parts purchased aside from a clutch disc.

almost there (i hope)!

How are you compensating for the additional bellhousing thickness when it comes to the flywheel/clutch/input shaft relationship? All things equal, just adding the adapter plate would put the input shaft that much further away from the splines of the clutch disc.

I'd pay good money for a tII adapter...or maybe even a t56 adapted. Now we're talking!!!

Anyone have a t56 template...I can make one with that and tim's awesome .dxf.

Turning tim's into a cleaned up .dwg right now so I can feed it into MasterCAD for the waterjet later.

I'm seriously considering skipping the Torsen route and using the Lincoln LS rear end to be ready for LSx power later. Using a t56 tranny as well would be a no brainer if I could get away with not making a custom interim driveshaft and use the whole kit. Would depend on where the spacer-tranny mating plane ends up in relation to the V8 installs.

I will do one custom driveshaft during the life of this car, but two would be stupid.


EDIT: Quick search netted some files in post #4 here:

http://forums.turbobricks.com/showthread.php?t=142381

Will have to check to make sure it's what we're really looking for...I've never even seen a t56 in person.

NEVERMIND....THAT'S A FORD T5

In all the reading I've done, I've found a handful of people who have done this to their 323 GTX/GTR's down in Australia and new Zealand. There's a smaller handful who have done it FWD, but it is essentially the same conversion minus the whole issue of the driveshaft, mounting the rear diff, clearancing the oil pan for the rear transfer, etc. None of them has mentioned a single thing about a flywheel spacer.

I wont know for sure until I get the plate and try to bolt things up, but I'm guessing that the BP flywheel must be thicker than the 3SGTE flywheel or something... so the height ends up being about right. Either that or the input shaft is longer than it "needs to be" for its stock application.

Regardless, I do have a plan in case I need to space it out. I will lathe the center out of an old flywheel, retaining the "lip" that centers it on the end of the crank. Then I can center it on the pilot bearing hole and precision lathe the front side of this piece down small enough to fit snugly inside the "lip" of my actual flywheel. I'll need longer/stronger flywheel bolts, but it should be thick enough to take up the space.

I just want a strong 5-speed or a 6-speed with realistic rations. Unfortunately my 3.63 is junk so I have to figure out something else.

I just KNOW I'll end up with an LSx in this car one day. If my turbo install was nicer/more powerful I might not, but it's just an interim power boost.

Everytime I see a "deal" on a Torsen I just think about how I'd sell it a few years down the road, and I have a buddy that's about to part out a Lincoln LS anyhow.

Trying to give myself an upgrade path. Mating a B series to a t56 may be a stretch though.

The toyota tranny idea sounds like a good one though, atleast for the FWD crowd.

this toyota transmission is unbelievably beefy... normally i can bench press the mazda trannies up into the car, while someone up top "aims" it onto the motor. ...i think i'm going to need to buy a transmission jack to get this thing in and out. i havent weighed the whole thing yet, but the LSD w/ring gear that i just bought weighs 30 pounds...

Worst case you have a flywheel built/cut to your specs. Go with an aluminum piece and you'll have something you can use forever with a replaceable mating surface. That looks like my solution for doing an entire bolt up of the TII trans to the FE using a Bongo van bell. Mazda did make the rwd R trans with a long enough shaft to do an entire bolt up, but the trans has suck ratios and only made it to the other side of the globe. Hard to justify when I got two TII trans for free (one bad for mockup, and one good).

i figured if i made the little "spacer" i described above, i could simply re-use it with another stock flywheel if my current one ever wore out too much.

i think a custom flywheel would be out of my price range, and aluminum isn't ideal as the car's main purpose (aside from a street car) is the occasional pass at the drag strip..

At that point you maybe able to just get someone to sell/mail you the input shaft of the longer R. That way you could swap out the shorter input shaft and still have the better gearing. I know when the N/A Rx7 guys swap to the miata intergearing they have to swap the inputs shafts due to length.

Splitime has a TII adapter plate, maybe he could send to someone to get it made into a file?