The miata guys steal FC NA rear end housings (Bigger R&P than early miatas) and then slap on the front of a miata housing. Boom, it's in their car, they can use 1st gen/etc short pinion gears.

Should be easily done for a NA FC: Grab the short miata front housing, throw it in with some easy to find/cheap 4.44 or 4.77 gears. Fab up something to support the front of the housing better as there will no longer be the stock 5speed NA type mount in use (Auto cars have nothing supporting the front anyways, right?) and have a longer driveshaft fabbed up. Right?

????

(Don't think I'll be doing this as I don't have a NA FC, or at least not one that doesn't think it's a turbo, but I'll sit back and dream of cheap/easy to get ahold of deeper 8" gears for the Boosted size punkin.....)

 

That's about it. The fun part would be fabbing a front mount for the diff.

On the other hand, I was thinking about putting a N/A RX-7 centersection in a 1st-gen. I don't know the difference in length, but it might be enough for to be able to use a T2 transmission and a stock driveshaft, no need to get raped out of $500 for a custom driveshaft.

 

TII tranny and "stock" shaft. Hmmm. Did anyone finally measure how the FC automatic shaft works out in that situation? The front yoke fits a TII box. I have one I can measure and compare to a TII driveshaft or something else to give someone an idea if they know how long it needs to be.

Look around and you WILL be able to build a custom shaft, if need be, for <$300.

 

Trying to sort out all these possibilities..

I took a quick peek at a spare FC rear and a 84-85 FB rear and it seemed that the pinion housing flange bolt pattern was different! Going to look side by side and snap some pics this evening.

I hauled home my extra driveshaft, next step see if the housings DO swap and then figure up length differences: FC automatic driveshaft, FC turbo driveshaft, and the 2 pinion housings. I bet there's a combo there that would make the TII boxed-FB an easy swap! (Except that my car is a '79...But the shifter issues are there no matter what!)

R

 

there is a difference of about 2 inches or so between the auto and T2 shafts. it will "fit", but i sure wouldnt put any stress on the driveshaft if you wanna keep your car running. basically it wont mate up correctly to be stable for anything other than light driving.

 

2" difference from a TII driveshaft might be just right for a FB running a TII box. I have no idea.

I think you're talking about replacing the TII driveshaft in a TII with the auto one? That's not what we're doing.

 

There is a thread on here somewhere about making the FB shifter assembly work on a TII box, or cutting down the TII one to fit. It's not that bad if you don't mind having a little machining done. The rod is a bit too long, has to be cut to length, and the appropriate holes/notches made- and the housing for it has to have a section cut out and welded back together.

Brad

 

p.s. I suggest cross posting this to the 1st gen forum. In fact, I am gonna copy it over, as it has some useful 1st gen info- and you MAY find that the 1st gen guys have some useful insights too.

Brad

 

TII Tranny into FB

 

I know I could put SOME of the FB shifter parts on the TII box: Doesn't quite fix the location for a SA22C car.

There is supposedly a mid '80 or something like that 12A gearbox that can have it's shifter parts removed like the later 12A boxes, that would make it short enough. No biggie.

"Short pinion gears in NA" only applies to 2nd gens. As all the 1st gen cars already can take them! But I see your point.... Since I'm also talking about "Long pinion gears in FB" as perhaps a means to swap trannies without needing a custom prop shaft...So I guess the bit that this thread applies to 1st gens is exactly the part that's missing from all the other TII tranny into first gen threads.

Although at least 3 people SWEAR the extension housings are swappable from FB to FC, I looked enough at my parts last night that I don't think so now. Unless some bolt holes are left un-used OR there are different bolt pattern housings out there...I've looked at '86 FC automatic, '89 FC 5 speed (both the same) and '84 or '85 first gen.

R