RX7 fd3s transmission in MX5
01-26-2008, 09:47 AM
#21
no- the advantage of bigT's solution is that you can cut the bell to position the input shaft where you want. Of course that'll also dictate the position of the stick thru the hole if you don't compensate for that. The miata solution typically is the adapter plate because it is easy and cheaper than the welding- and it works for as much power as anybody has made.
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01-26-2008, 11:15 PM
#24
no- the advantage of bigT's solution is that you can cut the bell to position the input shaft where you want. Of course that'll also dictate the position of the stick thru the hole if you don't compensate for that. The miata solution typically is the adapter plate because it is easy and cheaper than the welding- and it works for as much power as anybody has made.
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01-27-2008, 11:14 AM
#25
Loki - I have one rx7 bell, attached to the box. But I'm not going to give it up yet, not until I've completed the project. What I did was just call around to mazda shops until I found that had two of the boxes that were in the way. They gave them to me. Same shop gave me three 1.6 engines like five years ago. The owner is a racer, so he'd rather give them to me than the junk man. IMO a lot of these owners will take interest if you tell them what your up too - like a 300hp miata...
I thought there was somebody in fla on m.net that did a bunch of adapter plates... don't know if it ever came to fruition. I do think that Loki could probably sell at least 5 of them- more if he pushed them on m.net. Just need to figure out what it's worth to others, and to him.
I can't. I'm not doing it that way- different engine. I'm using a van bell housing which has the normal clutch fork position. I've already been through the resolution for the process on my own tho. I'm using a b2000 truck bell on a miata housing with an 80s 626 flywheel, 1.8 Miata clutch & pp. I made all my adjustments to ensure proper engagement/disengagement through the slave rod length- trial and error.
I thought there was somebody in fla on m.net that did a bunch of adapter plates... don't know if it ever came to fruition. I do think that Loki could probably sell at least 5 of them- more if he pushed them on m.net. Just need to figure out what it's worth to others, and to him.
I can't. I'm not doing it that way- different engine. I'm using a van bell housing which has the normal clutch fork position. I've already been through the resolution for the process on my own tho. I'm using a b2000 truck bell on a miata housing with an 80s 626 flywheel, 1.8 Miata clutch & pp. I made all my adjustments to ensure proper engagement/disengagement through the slave rod length- trial and error.
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01-27-2008, 04:13 PM
#26
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I have explain it many times. One of them, is here
It's not so sacrilege as you think.
Actually, the EM in my setup, is a custom, DIY management with 8 injectors, and it is very easy to tune.
At off boost situations,cold starts etc, is like a stock miata. Something that is very difficult to find and tune with stand alones.
Actually, the EM in my setup, is a custom, DIY management with 8 injectors, and it is very easy to tune.
At off boost situations,cold starts etc, is like a stock miata. Something that is very difficult to find and tune with stand alones.
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01-27-2008, 04:20 PM
#28
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The lever it's almost at the stock position (1 cm behind) as you can see at this foto
For some of the other questions, sorry but I cannot follow some of the elaborator meanings (not very good english
)
If I had better explains to some meanings maybe I could help better.
But I thing that the most have understand tottaly about the modification.
For some of the other questions, sorry but I cannot follow some of the elaborator meanings (not very good english
)If I had better explains to some meanings maybe I could help better.
But I thing that the most have understand tottaly about the modification.
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06-03-2010, 12:28 AM
#34
Because I have many answers about this modification, I decided to open a topic for this.
Well
The miata transmission is very nice, but can't handle safely more than 250 WHP.
At stock situations or at light turbo setups you 'll not deal with problems, but with 300+ WHP the 2th or 3th gear sometimes will gone
So there are two solutions
1)exotic stuff gears (os giken, quaife etc) but very expensive
2)adaptate transmission from another car, more inexpensive from the first solution but very difficult to do a perfect job.
So I put a turbo trans model "R" from RX7 fd3s (93-95).
It was from the beginning a difficult modification but the engineer succeed in this 100%.
The gear lever is exactly in the same position like the stock, and the "sense" of changing gears maybe is better than a stock transmission miata.
The 1-2-3d gears are a little shorter than stock gear ratio
The 4th is the same 1:1 ratio
And the 5th is much longer than stock ratio!! And this is very nice for a 380+ hp turbo miata!
The modification based to a new housing between the block and the RX7 transmission. We modificated the miata housing (bellhousing? ) and connect to its end, the end of the RX7 housing.It was a very difficult job because it had to be perfect at straight line with the stock one.
You will see at the fotos what exactly we have do because my english are not so good to explain exactly what I want to tell.
The driveshaft was cut and modificated to match to the RX7 transmission.
Well
The miata transmission is very nice, but can't handle safely more than 250 WHP.
At stock situations or at light turbo setups you 'll not deal with problems, but with 300+ WHP the 2th or 3th gear sometimes will gone
So there are two solutions
1)exotic stuff gears (os giken, quaife etc) but very expensive
2)adaptate transmission from another car, more inexpensive from the first solution but very difficult to do a perfect job.
So I put a turbo trans model "R" from RX7 fd3s (93-95).
It was from the beginning a difficult modification but the engineer succeed in this 100%.
The gear lever is exactly in the same position like the stock, and the "sense" of changing gears maybe is better than a stock transmission miata.
The 1-2-3d gears are a little shorter than stock gear ratio
The 4th is the same 1:1 ratio
And the 5th is much longer than stock ratio!! And this is very nice for a 380+ hp turbo miata!
The modification based to a new housing between the block and the RX7 transmission. We modificated the miata housing (bellhousing? ) and connect to its end, the end of the RX7 housing.It was a very difficult job because it had to be perfect at straight line with the stock one.
You will see at the fotos what exactly we have do because my english are not so good to explain exactly what I want to tell.
The driveshaft was cut and modificated to match to the RX7 transmission.
Don't know why you would want an FD tranny. They aren't exactly known to be reliable. Ask me about my two broken trannys from my FD sitting in my shed.
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06-03-2010, 12:36 AM
#36
The first one shredded 3rd gear shifting from 2nd WOT when the car was stock. Approx 250ish whp. The second I blew the 5th gear syncro (known problem in the FD trans) at 380whp. The current one is holding strong. We'll see how it lasts.
FD guys swap TII trans in because they are stronger. Go for the TII.
Guys on the FD forums are known to refer to the FD trans as glass... lol
FD guys swap TII trans in because they are stronger. Go for the TII.
Guys on the FD forums are known to refer to the FD trans as glass... lol
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06-03-2010, 12:42 AM
#37
From what I have seen doing research, the only differences between the TII tranny and the turbo FD tranny are the syncros which made it shift better (although it would appear otherwise in your situation). Powerwise I'm being told it's a wash. I've gotten all this information from FD owners.
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06-03-2010, 01:09 AM
#38
You're right on the smoothness of shifting. The TII won't be right there... but from my understanding it will hold more power and take a bit more of a beating before any issues arise.
Realisticaly, for a Miata power wise you're OK with either. Syncro wise, I would say to go with the TII. Or have an FD box rebuilt with all new syncros and run good fluid from the get-go.
Realisticaly, for a Miata power wise you're OK with either. Syncro wise, I would say to go with the TII. Or have an FD box rebuilt with all new syncros and run good fluid from the get-go.
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06-03-2010, 08:57 AM
#39
What's odd is that those transmission are both essentially the same unit- based on the same Mazda R gearbox. I suppose it's possible that changes to improve drivability were done at a compromise to strength. You never hear of people braking the TII version in a Miata- and this is the only case I know of that is using the FD box.
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