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Thought I would Add, Quaife gear set in 5 speed box, 1.5 years broke second gear teeth. ~330 ft-lbs 275 Hoosier A7s
Sorry to hear that Bob. Was it on the track or autocross course? My theory is that failures are heat-related, as I've broken two boxes during track use. Years of autocross and aggressive street driving, on the other hand, were completely uneventful.
Awaiting a turn-key(-ish) T5 solution so I can get my car back on track, so to speak.
Sorry to hear that Bob. Was it on the track or autocross course? My theory is that failures are heat-related, as I've broken two boxes during track use. Years of autocross and aggressive street driving, on the other hand, were completely uneventful.
Awaiting a turn-key(-ish) T5 solution so I can get my car back on track, so to speak.
I've done nothing but autocross since I put in the quaife. full power run in second from ~30mph to ~ 70 going through the finish with a little grip help from the pavement undulation no shift involved. run was good for FTD even over a real A-mod car and overall top PAX. Do you use 275 Hoosiers for autocross?
I've done nothing but autocross since I put in the quaife. full power run in second from ~30mph to ~ 70 going through the finish with a little grip help from the pavement undulation no shift involved. run was good for FTD even over a real A-mod car and overall top PAX. Do you use 275 Hoosiers for autocross?
No, 225-section NT-01s. I did manage to blow up my Torsen at the drag strip, where available traction (coupled with some wheel hop) shattered the worm gears. I've since eschewed the drag strip but, given my diff is now a much stronger Guru, I suppose the gears are the next "fuse" in the driveline (or, perhaps, the half shafts).
No, 225-section NT-01s. I did manage to blow up my Torsen at the drag strip, where available traction (coupled with some wheel hop) shattered the worm gears. I've since eschewed the drag strip but, given my diff is now a much stronger Guru, I suppose the gears are the next "fuse" in the driveline (or, perhaps, the half shafts).
Transmissions started blowing up much more quickly on the track when I went to 245/40/15 hoosiers on 10" wheels for the track. 4th gear on a six speed was good for about 4 track days and I turn the boost down for the track it drops 40-50 ft lbs. over my all of it autocross mode. I think the 6 speed 1st and second may be stronger for autocross than the quiafe but it adds about 12 lbs of weight most of which is rotating parts. Rear end ratios need to be at opposite ends of the spectrum as well. For autocross I run a 4.778 with the quiafe and 3.636 with the 6 speed. Quaife 2nd through 5th is real close to 3rd through 6th on the six speed but for autocross I set the second gear ratio I want.
Hope you don't mind, but filled in some blanks on the AZ6. Anyone have any idea how different some of the shaft / bearing diameters are? I made a spreadsheet where I back-calculated tooth counts of the available AZ6 boxes and there's some interesting options mixing and matching gears a bit.
Hope you don't mind, but filled in some blanks on the AZ6. Anyone have any idea how different some of the shaft / bearing diameters are? I made a spreadsheet where I back-calculated tooth counts of the available AZ6 boxes and there's some interesting options mixing and matching gears a bit.
Don't mind at all! Happy to have others working in it, updating it, etc. I'm hoping it can be of some use to the community and helps me keep my sanity when looking at all the options.
Would anyone here be interested in attempting a Toyota R-series transmission swap? I have some adapter plates in stock... but they were made to connect a transverse mount BP to a transverse mount toyota E-series (camry v6, MR2 turbo, celica alltrac). This means they aren't a perfect fit for the miata, but I think they could be workable. I've thought through the potential obstacles as far as I can without actually trying to bolt some stuff together. Monk loaned me a toyota v6 truck bellhousing.... I do not recall exactly what kind of truck it came out of, hopefully he will chime in. I do know it will bolt to the Supra R-series which has much more desirable gear ratios. I test fitted one of my plates against this bellhousing to see how far off it would be, these were the results. I've attached two photos, one original, one marked up.
Red: These are the transmission-side bolt holes which line up. Unfortunately these are all M10 and M12 holes on my plate, yet they coincide with much larger M16 holes on the bellhousing. Not a huge issue, but won't help you out very much with alignment, which brings me to the next issue.
Green: This is the only dowel pin hole which lines up; it is the correct size (M10). The second dowel pin in my design fits into an M10 hole in the plate which does not exist on this bellhousing. (It's the top hole marked in blue.)
Blue: These are unthreaded holes in my plate which are meant to have bolts or dowel pins pass through them and into the transmission.
Yellow: These are threaded holes which are meant to receive bolts from the transmission side.
Unmarked: All of the unmarked holes are mazda-side holes.
Regarding tilt/orientation:
The bellhousing is roughly 15" in diameter, and the water drain groove in the center bottom of the bellhousing is offset to the drivers side by about 2.5". This works out to a rotation of about 19-20 degrees if I'm doing the math right. I have a feeling this wouldn't cause any functionality issues with the transmission, however it might increase the chances of the trans hitting the floor pan somewhere. Might need to bend the shifter towards the driver a bit too.
Regarding the blue/yellow holes:
It should be relatively easy to use the adapter plate as a jig to make some new holes in the bellhousing flange, so that you can have more than 3 bolts holding everything together. Most of these locations have enough material behind them for this, but a couple of them you may need to weld on a small chunk of aluminum to give you enough meat to bolt to. With some thought, 1-2 of the starter mounting bolts can also be used to help tie everything together.
Regarding having only a single dowel pin, and making this actually work:
I feel the best option would be to turn the topmost red hole in my drawing into a second dowel pin location. I selected this location because it's one of the two that are not right next to the existing dowel pin, and of those two it's the only one with a second bolt hole available right next to it. A custom pin would have to be machined, with ~3/8" of tight fitting M12x1.75 threads on one end and a ~16mm dowel pin on the other (I'd need to take a more careful measurement of this hole). This isn't ideal as Toyota never intended for it to be a dowel pin hole, and thus the diameter and location tolerance may not be quite as precise, but it would be our best shot.
Other issues/notes:
- If i recall correctly the miata uses different hole locations on the oil pan compared to the fwd/awd BP. If any of the holes do line up, you'd probably need to drill out the threads in the plate in order to use them.
- With an appropriate drill centering collar, the hole for the drivers side engine dowel pin can be continued into the bellhousing and tapped, allowing you to bolt all the way through the engine/plate/trans assembly on that side. You can either go with ~M10, or drill out the M12 threads in the block and go with M12.I have something like 18 of these adapter plates left on the shelf right now and I'm selling them for $325 shipped in the lower 48. If anyone is interested in buying a plate and giving this a try, I have a machinist friend who can probably make the custom dowel pin I have described above. He has whipped up custom hardware for me in the past.
Would anyone here be interested in attempting a Toyota R-series transmission swap? I have some adapter plates in stock... but they were made to connect a transverse mount BP to a transverse mount toyota E-series (camry v6, MR2 turbo, celica alltrac). This means they aren't a perfect fit for the miata, but I think they could be workable. I've thought through the potential obstacles as far as I can without actually trying to bolt some stuff together. Monk loaned me a toyota v6 truck bellhousing.... I do not recall exactly what kind of truck it came out of, hopefully he will chime in. I do know it will bolt to the Supra R-series which has much more desirable gear ratios. I test fitted one of my plates against this bellhousing to see how far off it would be, these were the results. I've attached two photos, one original, one marked up.
Red: These are the transmission-side bolt holes which line up. Unfortunately these are all M10 and M12 holes on my plate, yet they coincide with much larger M16 holes on the bellhousing. Not a huge issue, but won't help you out very much with alignment, which brings me to the next issue.
Green: This is the only dowel pin hole which lines up; it is the correct size (M10). The second dowel pin in my design fits into an M10 hole in the plate which does not exist on this bellhousing. (It's the top hole marked in blue.)
Blue: These are unthreaded holes in my plate which are meant to have bolts or dowel pins pass through them and into the transmission.
Yellow: These are threaded holes which are meant to receive bolts from the transmission side.
Unmarked: All of the unmarked holes are mazda-side holes.
Regarding tilt/orientation:
The bellhousing is roughly 15" in diameter, and the water drain groove in the center bottom of the bellhousing is offset to the drivers side by about 2.5". This works out to a rotation of about 19-20 degrees if I'm doing the math right. I have a feeling this wouldn't cause any functionality issues with the transmission, however it might increase the chances of the trans hitting the floor pan somewhere. Might need to bend the shifter towards the driver a bit too.
Regarding the blue/yellow holes:
It should be relatively easy to use the adapter plate as a jig to make some new holes in the bellhousing flange, so that you can have more than 3 bolts holding everything together. Most of these locations have enough material behind them for this, but a couple of them you may need to weld on a small chunk of aluminum to give you enough meat to bolt to. With some thought, 1-2 of the starter mounting bolts can also be used to help tie everything together.
Regarding having only a single dowel pin, and making this actually work:
I feel the best option would be to turn the topmost red hole in my drawing into a second dowel pin location. I selected this location because it's one of the two that are not right next to the existing dowel pin, and of those two it's the only one with a second bolt hole available right next to it. A custom pin would have to be machined, with ~3/8" of tight fitting M12x1.75 threads on one end and a ~16mm dowel pin on the other (I'd need to take a more careful measurement of this hole). This isn't ideal as Toyota never intended for it to be a dowel pin hole, and thus the diameter and location tolerance may not be quite as precise, but it would be our best shot.
Other issues/notes:
- If i recall correctly the miata uses different hole locations on the oil pan compared to the fwd/awd BP. If any of the holes do line up, you'd probably need to drill out the threads in the plate in order to use them.
- With an appropriate drill centering collar, the hole for the drivers side engine dowel pin can be continued into the bellhousing and tapped, allowing you to bolt all the way through the engine/plate/trans assembly on that side. You can either go with ~M10, or drill out the M12 threads in the block and go with M12.I have something like 18 of these adapter plates left on the shelf right now and I'm selling them for $325 shipped in the lower 48. If anyone is interested in buying a plate and giving this a try, I have a machinist friend who can probably make the custom dowel pin I have described above. He has whipped up custom hardware for me in the past.
Questions.... GO!
I might be interested in one but it would more likely be to mount a Toyota Alltrac transmission into my GTR powered BF 323 GTX. building a nationally competative street mod car out of a GTX has been an Idea kicking in my head for a while. it would take an altrac transmission to hold up to needed power and grip levels.
So, my replacement 3rd gear set finally arrived from England (by way of FM, by way of the North American distributor). My car is in the shop and the tranny was stripped down to reveal the offending part. One tooth only.
Everything else looks clean, syncros are like-new and the box is back together again. I should be on the road again next week, hopefully (knock on wood) in time for my upcoming pilgrimage to FM for Summer Camp. Regardless, street only for me from now on, until a T5 kit is available. At that point, I'll trade some sweet-shifting deliciousness for track-all-day bulletproofing and sell my Quaife box to someone who will swear on a stack of Enthusiast Shop Manuals to never, ever darken a track paddock.
So, my replacement 3rd gear set finally arrived from England (by way of FM, by way of the North American distributor). My car is in the shop and the tranny was stripped down to reveal the offending part. One tooth only.
Everything else looks clean, syncros are like-new and the box is back together again. I should be on the road again next week, hopefully (knock on wood) in time for my upcoming pilgrimage to FM for Summer Camp. Regardless, street only for me from now on, until a T5 kit is available. At that point, I'll trade some sweet-shifting deliciousness for track-all-day bulletproofing and sell my Quaife box to someone who will swear on a stack of Enthusiast Shop Manuals to never, ever darken a track paddock.
I haven't taken mine apart yet but I think I will find one tooth missing from second gear. And when I got it from you it had one tooth missing from the input gear on the lay shaft. In the stock boxes when one tooth goes all the rest go almost immediately.
The Nissan CD009 is a great option for the money ($1500 brand new), and holds a lot of torque.
Cusco gearset is also available.
Gear ratios not the best, however: 3.784, 2.324, 1.624, 1.271, 1.000, 0.794
The cost of the trans really has not been the big issue. The issue is getting it so it mates to the miata engine, the ppf, and has the shifter in the correct spot.
For those that might have subscribed to this thread, here's a heads-up that I'm selling my Quaife box, mostly because I'm looking for a little more peace and quiet on long road trips (which, since I bought the MSM for track use, is mostly what I use my '93 for nowadays). A good, robust solution for non-track use that is completely plug 'n play, shifts like stock and has near-perfect gear ratios for high-powered cars. Just bring ear plugs for those long transit sections.
06-21-2016, 12:31 PM
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