HOZZMANRX7

iTrader: (43)

I need not only a JSpec "T2" Automatic tranny, but the tranny computer as well for a 89-91 Rex.

Located tranny's from a JSpec importer, but the computers never come with from Japan. The NA Computer doesn't work as the shift points are different for the power and torque of a T2 engine.

Wondering if a tranny computer from a 3rd Gen would even talk to a 2nd Gen Auto Tranny or shift properly.

Thoughts.... suggestions?????

No7Yet

Why wouldn't the N/A auto tranny work? both the N/A and TII motors have similar torque curves, the TIIs is just higher. The shift points would be the same, mostly dependant on throttle position (and full-throttle shifts would be made at redline). The Hold function should operate the same, as well.

*shrug* In the end, I guess I don't really know

Brandon

HOZZMANRX7

iTrader: (43)

Spoke with a local forum member that did exactly that, T2 engine to N/A Auto Tranny. The shift point problem was the key issue he pointed out in this set up. In fact, the problem has been so consistant that he is now in the process of changing out his tranny from an Automatic to 5 speed.

Thus, my hope one of our Europe or Japan brothers or sisters can help me out here as T2 Automatics were available there. For additional reference, the Tranny Computer is mounted just under the Glove Box.

No7Yet

Don't discount your aussie brethren Maybe try talking to Perry Gehenna? He should be able to help ya, or at least tell you who can.

Can you explain exactly how N/A shift points can be detrimental on a TII? I'm not too well-versed in the auto tranny world (they're something of a mystery to me). How is a shift point calculated? Does it have to do with torque converter lockup? Should I ask some of the guys over at the Buick GN forum? :p

Brandon

Node

iTrader: (1)

how about a FD auto tranny?
Or is that too much of a hassle?

HOZZMANRX7

iTrader: (43)

G'day Mate!! Any of my Aussie brothers out there that help me out also??

As explained to me, the NA auto tranny computer looks for shift points appropriate for the horse and torque power of a NA engine. Thus, it would down shift and upshift earlier under a load than what it should. The forum member I spoke with advised he has tried everything and can only conclude it's the computer. Also, the power of a T2 engine indeed seems to be more than what the NA Auto tranny can deal with long term. So, I have to believe a T2 Auto Tranny has stronger components than a NA Auto tranny, just as is the case in a Manual tranny.

Node,

I thought of that also, but the tranny mount location, I don't believe, will line up unless I do some serious fabrication. More so, a driveshaft the correct length from a 3rd Gen tailshaft to 2nd Gen rear Diff would require serious fabrication also. And, I really don't want to deal with the cost nor durability issues of fabricated parts.

I'd LOVE to hear from anybody that has any experience with ANY 3rd Gen tranny into a 2nd Gen.

Rob500

2nd gen automatic trans cars use manifold vacuum as part of the transmission control logic. As I understand it 3rd gen auto trans cars do not. Mazda had to design a means to control positive manifold pressure on a auto trans turbo car. Check valves don't seam to work very well. Mazda may have done this in the transmission computer logic. We really don't know what they did. Another issue is that the transmission acts like it is bolted to a 160 hp na car. In other words it wants to try to keep the engine rpm's on top of the na torque curve. This is really annoying on a car that has significatly more torque than a stock na car. My guess is that the easiest thing for Mazda to do would have been to modify the transmission computer on the turbo cars. It would be nice to talk to a Mazda engineer.

Rob

HOZZMANRX7

iTrader: (43)

Thanks Rob. You are obviously a man of great insight on this issue.

Europe, Asia, Australia, Japan forum members, you out there??

I reallllllllly want to take on this project, but am in dead water without the computer (and perhaps the wire harness to it).

Gotta be something here you want/need so we can help out each other......