Hi,

I am going to be putting a TII trans into my 85 Rx-7 12a turbo. Can you guys please tell me the differences between the S4 TII and the S5 TII transmissions.... i will need to change the bell housing I'm sure. I was just trying to see if there are any benefits/downfalls to one over the other?

Thanks

 

the cross members are different and s5 has a taller 5th gear

 

is that all? ive heard differences in appearences like number of ribs... which doesnt matter really... anyone know which one will fit more easily into a 1st gen... i should probably ask that in the first gen section...

 

I have a GSL-SE and I had an S4 transmision in it which I then swapped out for an S5 when I blew that one.

As stated, the crossmembers are different so I pulled the tail off the S4 and put it on the S5 as I had already made a bracket for it. There is also a counter-weight in the S5 that I removed. Bolted right in.

 

wonder if first gen tail will bolt on to TII?

 

^

Negative.

1st gen and N/A transmissions are much smaller and lighter than the "Rib case" turbo versions.
There is no parts interchange save for possibly the shifter.

 

So if i get the s4 tII tranny and bolt it up to my 12a can i use the stock 12a flywheel with a tII clutch? Then just use a tII starter and slave?

 

No. Clutch diameter is different.

You'll need a custom clutch disc with Turbo transmission splines and the outer diameter to fit the 12A PressurePlate and flywheel...

OR

You'll need to machine down the 13B' Turbo's counterweight on the back of it's flywheel to match the 12A rotor weight.

OR

You'll need to get a 12A Automatic transmission counterweight and an aftermarket 13B Turbo flywheel.


I choose the final option because it involves off the shelf parts and no custom made crap that may have limited availability and questionable quality if you choose a shady machine shop.

 

"You'll need to get a 12A Automatic transmission counterweight and an aftermarket 13B Turbo flywheel."

Think ill go with this option...