This is probably a dumb question but I cant figure it out. I want to do this http://go.jeep-xj.info/HowtoAutoSwitch.htm but I dont understand the torque convertor controller part or when to be locked and when to be unlocked.

 

my buddy had this done on a ford mustang...Locking the convertor allows for no slip so you make more power....He locked it in OD and if he was gonna punch it froma roll only ... or it will bogg down the motor from a stop because its like coming up to a light with a manual and not pressing in the clutch

 

I am wiring in a thumb switch on mine so it will lock when I want it and also automatically. If you have a push button switch it won't stay locked when you don't want it and you will have the best of both.

 

So when do you lock it?

 

anytime you arnt sitting still....but the point of my buddy doing it on his mustang is because with it locked you make more power........and it should automatically lock on the highway..........IMO this mod is worthless...........

 

Half marks. You don't "make" any more power - what you're doing is eliminating the "slip" inherent in the torque converter design.

A TC is a three-part hydraulic power transfer coupling, while the typical (manual transmission) clutch is a three-part mechanical coupling. The clutch will slip until it is fully engaged, then it's a 1:1 coupling.

The torque converter, at its best, manages to be about an 1.18:1 power transfer coupling - meaning you're losing 15-18% of input power through the coupling (this is also a large part of why automatics need cooling - all the fluid shear in the TC equates to heat generated.)

The addition of the TCC (Torque Converter Clutch) in the last twenty years has been a large help for fuel economy, towing, power efficiency, and parts longevity.

Typically, the TCC is engaged by the TCU (Transmission Control Unit) in gears higher than second, when at a "steady-state" cruise. It may stay engaged when you stick your foot in it to pass someone (accompanied by a "kickdown" shift,) and it is usually disengaged immediately when you press the brake pedal. The TCC is a hydraulically-actuated mechanical clutch inbuilt into the TC proper.

If you want to force the TCC for takeoff, you want to engage it just after you've hit the accelerator pedal. You can also force the TCC at pretty much any time you're at a steady-state cruise, but I'd advise you to "unforce" it if you have to change speeds significantly. The use of a "momentary" style pressbutton switch is most advisable - that will allow it to remain engaged while the button is held down, but it works like a "dead man's switch" in that it will release the TCC if you release the button (unless you're at cruise, and the TCU has engaged it anyhow. Then, no harm done.)

Typical TCC force mods are set up as a Logical OR circuit (I believe Marcus' is as well,) where the TCC will engage if the TCU wants it to OR you are holding down the switch.

The key advantage (for us) in a TCC force mod is that it will allow the TCC to be engaged at a much lower speed - which will reduce fluid shear (as mentioned,) reducing heat generation in the transmission and reducing the heat rejection requirement on the cooling system. This is also good for your engine oil - so it's not a bad thing at all! Just use it carefully...

 

So if I use a momentary push button and lock the torque converter at take off it will give me more low end or am i still misunderstanding. I think so far if I do this mod I will have four switches:
1.solinoid 1 power
2.solinoid 2 power
3.torque convertor lock up
4.some sort of switch to go from manual to automatic
any suggestions or am I making it more confusing than what it really is.

 

When off roading. I have deep gears with an Atlas 4 speed and 10.38 tcase gear ratio. Hit the switch and let it idle. It takes the heat out of the tranny from slipping the torque converter and the jerkiness out of the ride.