1st Generation Specific 1979-1985 Discussion

Recommendations On a Bulletproof Tranny?

Old Apr 16, 2006 | 03:09 AM
  #1  
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So my car is currently out of commision because of a broken trans, this would be #2 broken since the ported engine, seems like the stock '79 trannies just can't take the power, I've been through 1 GSL-SE rear also, i don't do alot of drag racing, just a little drifting and a track day or two at the autocrosses... i want something that will hold up to being supercharged as well (summer project)...



To get to the point i only want to replace the tranny one time, which would you use, or where can i get a "heavy duty" rebuilt one...



I believe i have the rear end figured out, but i'm up for suggestions on that too



Thanks

Shay
Old Apr 16, 2006 | 04:31 AM
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Turbo II transmission, GSL-SE crossmember (+$10 worth of home depot parts), and a custom driveshaft. Held up to 350+ hp 13Bt.



I've gone through 3 of those GSL-SE rear-ends... You know the Miata guys swear those 7" diffs are unbreakable.
Old Apr 16, 2006 | 05:02 AM
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Originally Posted by ducktape' post='814183' date='Apr 16 2006, 05:31 AM

Turbo II transmission, GSL-SE crossmember (+$10 worth of home depot parts), and a custom driveshaft. Held up to 350+ hp 13Bt.



I've gone through 3 of those GSL-SE rear-ends... You know the Miata guys swear those 7" diffs are unbreakable.


duck... how much you want for them *****... Mine isn't broken... yet! But you even know when you might need it.
Old Apr 16, 2006 | 09:57 AM
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Yeah, do like Duck said and go with the TII tranny. You shouldn't be able to break one with any kind of NA power. The swap is fairly straight forward and well documented on rx7club. The driveshaft will probably set you back about $350 to have a new one made.
Old Apr 16, 2006 | 12:08 PM
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I have heard through a couple people that TII's are good up to 700rwhp. No personal experience though.
Old Apr 16, 2006 | 05:07 PM
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i broke a couple teeth of the ring gear with a stock motor.....
Old Apr 17, 2006 | 07:18 AM
  #7  
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Originally Posted by Xtreme' post='814184' date='Apr 16 2006, 06:02 AM

duck... how much you want for them *****... Mine isn't broken... yet! But you even know when you might need it.


I'm currently selling the driveshaft from my TII swap: https://www.nopistons.com/forums/ind...howtopic=61245



The tranny I used ended up going to Jamie in Palmyra, so you'd have to source another gearbox. I can show you how to make the adapter needed to mount the tranny.



Be aware, if you choose to swap in the TII box you must either modify the shift linkage and tail, or notch the shifter-tunnel to make room for the stock unit. This moves the shifter back a little under an inch. Don't worry about it too much tho, it doesn't affect the surrounding trim and you really can't tell any difference.
Old Apr 17, 2006 | 11:31 AM
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I have heard through a couple people that TII's are good up to 700rwhp. No personal experience though.
I just sold my TII tranny to a guy running far less than 700hp who blew his factory TII tranny.



I'd go with a TII tranny and GSL-SE rearend and treat it nicely. But if you're blowing your transmission with a naturally aspirated motor and planning on supercharging, you might start looking at a T-5/Mustang 8.8 swap. It would be a pain in the butt and require quite a bit of fabrication/welding, but it should hold up to about 500hp with sticky tires. If you break that, there are plenty of beefier parts to swap into those housings.
Old Apr 17, 2006 | 11:36 AM
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Good to know...a lot of stuff on forum is word of mouth. Part of why I put that I had just heard it. I hate to fall victim to that game.



You could always get the gear cryo-treated and backcut...
Old Apr 17, 2006 | 12:44 PM
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Man I feel your pain. I have been through 3 rearends and and Im on tranny #4. As far as rear ends save your money and go with a nine inch ford or an 8.8. tranny wise go with a seconed gen. It is an easy swap no cutting no custom drive shaft at least with the na. I dont know about the turbo II. Take the tail housing and shift rod assembly off your 1st gen tranny. remove the same off the seconed gen trans. take the 1st gen tail housing and shift rod assembly and put it on the seconed gen trans. By using the 1st gen tail you get to use the same cross member and drive shaft. I just did this mod to my car and so far am pleased.

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