I just finished rebuilding a pontiac 4T60E electronically-controlled FWD auto tranny. Learned a heck of a lot about slushboxes... And it got me thinking. (Usually a dangerous situation when I get thinking...)

These ideas are related to a pontiac tranny, but the basic design should port over to a Nissan slowtomatic tranny...

The shift lever postion (The "Manual Lever") determines which ranges the tranny can operate in. We all know that 1 limites a tranny to 1, 2 to 1 & 2 etc. In the electrically controlled tranny a signal from the computer tells the tranny what actual gear to use.

The way it dows this in the 4T60E is by two shift solenoids. These work similar to this table below (these actual settings may be wrong, but the theory is right)

A=Solenoid A
B=Solenoid B
1=On
0=Off
G=Gear

A B G
0 0 1
0 1 2
1 0 3
1 1 4

So - If the computer can signal the tranny what gear to be in by just setting two wires to on or off, then can you make a device that sits in the middle and intercepts that signal. You can even make a relatively simple device that would allow you to force the tranny to the gear you actually want...

If I were to do this the device would be controlled by logic circuits that would select gears like this;

C=The gear that the Computer has selected
D=The gear that the Driver has selected
G=Actual Gear that device tells the tranny to use
O=Override driver to protect tranny/engine
X=Device turned off (default to computer control)

C D G
4 X 4
4 4 4
4 3 3
4 2 2
4 1 2 O! Definite Engine Overrev
3 X 3
3 4 4
3 3 3
3 2 2
3 1 1 O? Possible Engine Overrev
2 X 2
2 4 4 O? Possible Engine Labor
2 3 3
2 2 2
2 1 1
1 X 1
1 4 3 O! Definite Engine Labor
1 3 3
1 2 2
1 1 1


Just thoughts... Anyone else got any input? Why it would be waaay cool, or why it would suck ***/grenade the tranny? The only downside I see would be that the computer would detect a difference between the actual output speed and the expected output speed and probably throw a code "Transmission slip" or sumfin...

Any auto-tranny gurus wanna add thier 2c?

(Me? I drive a 96' SE 5Spd so I don't need this myself - but I'm gonna buy a POS car to test some performance ideas I had soon. I don't do mods on my daily driver...)

 

That is a great idea, its almost the same as Daniel B. Martin posted almost a year ago . Another way is to use the HKS shift control device they sell for automatic Z32 300zx's. I could get you pics of the wire harness so you could match them up with yours.
http://forums.maxima.org/showthread....ighlight=shift

 

am i the only one who said wtf?

 

Nope

 

COunt me in this category...

 

I dont know what you said, but it sounded cool. I really want a shiftable auto, if you guys figure out how to do this it would be a great contribution to the .org

 

Dont the newer autos (2000+) have tiptronic shifters? Is that basically what you're trying to do? If so, why not try and adapt the new tranny to your car...might be a cheaper alternative.

Sorry I know nothing about autos so just ignore this if I totally have the wrong idea.

 

Where in the flippity flip flip did you get that info from, that is a VERY good theory......I hear another Daniel B Martin coming in the horizon.....

 

never mind traitor..

very good theroy BTW

 

im lost
anyone got the map?

 

C D G
4 X 4
4 4 4
4 3 3
4 2 2
4 1 2 O! Definite Engine Overrev
3 X 3
3 4 4
3 3 3
3 2 2
3 1 1 O? Possible Engine Overrev
2 X 2
2 4 4 O? Possible Engine Labor
2 3 3
2 2 2
2 1 1
1 X 1
1 4 3 O! Definite Engine Labor
1 3 3
1 2 2
1 1 1


This looks like the begining of a nice word search

 

actually it looks like something out of the mid 90's when pagers were cool, and doing messages between friends. the X's represent spaces and such.
ok im bored
im still lost