I keep getting different answers on this. Please can someone verify this for me. Preferably someone that has done it. Can a jspec motor be bolted up to a 12A tranny w/out modification?

Thanks, Ed

 

Yes the block bolts up to the tranny. However the stock turbo flywheel and clutch will not suit your tranny and starter. Youl will need a rear counterweight for your year engine, aftermarket flywheel for your 12a tranny and a clutch setup for your 12a to match it.

Note that the 12a tranny will not take a lot of abuse with a turbo engine...

 

Okay so If I get an aftermarket flyweel with counterweight I would be able to bolt this up to my 12A tranny and use the 12A starter witht the 4puc clutch set up that I have now?

Thanks, Ed

 

Ed, the 13b TII flywheel and starter is much different than the na stuff.
To be honest if your using a TII motor instead of using the 12a stuff for what little bit of time it will last, sell it and buy a TII tranny and starter. Then build a shaft for it and your on the road. Another thing to get if you don't have one is the LSD rear from a se or gsl.
I am doing the same process S5 TII Motor/Tranny into a SA.

If you must use the 12a stuff a 12a flywheel with the correct counter weight should work. Make sure to get the counter weight the same as the year motor your using. Example 87-88TII get a 87-88 counterweight amd the same with S5 TII. The flywheel is a big expense and would be cheaper in the long run to go to a TII tranny now.

 

Okay thanks for the info guys. Does anyone sell ready made shafts for this swap? Considering the price of an aftermarket flywheel and counterweight its actually more economical to go ahead and swap the tranny too.


Thanks, Ed

 

Ed, the cheapest way to go would be to buy a TII drive shaft or just the end that fits into the TII shaft and take it to a drive shaft shop to have them put a front TII shaft on a 1st gen or a 2nd gen na rear shaft.

I have to get a TII to s4 NA shaft made and a TII to a 1st gen shaft made in the next few weeks.
CHad

 

Chad, let me know how this works out. Total cost and what not. Maybe I'll go this route as well.

Thanks, Ed

 

do a full t2 drivetrain conversiona nd youll never have to work about things breaking down there. and you wont have a wack open diff.

 

The 12A transmission will hold up fine to the TII power as long as you don't come out of the hole clutch dropping at 8K rpms. MikeyD had a 12A transmission behind his TurboII motor with a rotaryshack blowthru running mid low 12's all year long.

 

This might be true but for the same cost to say 12a he can go TII, so why stay 12a? It don't make sense.

 

but that badass rear end in there too. If your looking for a strong rear end go with the s4 t2 rear end ,but the lsd isnt as good for turning as the s5 ,but it is the strongest of the 2

 

Depends what parts he already has laying around...

Also the 12A trans has a shorter gearing making any set-up feel faster off the line and acceleration. I guess it depends what he's looking to do with the car.

 

This if for an 83 GS w/a GSL rear. I knew I heard of someone running the 12A tranny I just couldnt remember who.

Thanks, Ed

 

Would you care to explain how common this swap is, who has done it and how? Also how is it that the 3rd gen guys often prefer the S4 lsd over the viscous S5 lsd. Neither of which will fit in a 1st gen without major fabrication to change from a solid axle to irs.

The automatic drive shafts have the same yoke as the TII's, if one cannot find a TII shaft.

 

S4 TII rear end in a 1st gen...... no way toooooo much trouble when a gsl or gslse will work just fine.

 

Yeah Turbo II-FB, WTF are you talking about? You do realise that this is the 1st gen forum?

Ed, I've seen a Cosmo 13B with a T04B single turbo attached to a 12A tranny and through a GSL LSD diff and it worked great! The key with that setup is just not to be doing crazy launches with it or the tranny will break for sure!