Well the master at the A604 has done it again and come up with a simple switch to defeat TQ lockup
here is Roberts Post from ASOG
he thinks it might be worth a couple 1/10's in the quarter mile

"After long research by my self and another member its done, my car is not here so I did not test the mod but it has been tested by another member.

Here are Directions to defeat the torque converter lockup without turning on
the brake lights. GREAT for city cruising.
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My 1995 Chrysler shop manual is incorrect from the factory and shows that
the brake light switch is NORMALLY OPEN on both poles of the double pole
single throw tail light switch. That is incorrect. It's normally open on the
brake light side and normally closed on the torque converter lockup side.
The manual has several pages you need to find to figure out the different
systems and their function. That's why it's taken me so long to get this mod
to work.

Feel free to post it if you wish.

Attached is a drawing that I made that is correct and replaces the one in
the manual. (I don't know if the 96 and up manual has been corrected.)

All you need to do is OPEN that ground circuit to make this mod work.
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Parts............................

1 single pole switch (or SPDT for an indicator light)
6 feet of #18 wire
2 #18 butt connectors
2 spade terminals

Directions..................................

Mount the Lock Up switch.

Locate the brake light switch under the dash. Disconnect the quick connector
from the switch.

cut the Black wire from the brake light switch and strip back 3/8" of
insulation.

cut the #18 wire into 2 - 3' pieces, strip 3/8" from both ends of each piece

use the butt connectors and spades to crimp them to your 3' pieces.

crimp the butt connectors to the cut black wires

install the switch

test

NOTE: You could use a single pole double throw switch and a small light
mounted in the dash to illuminate if the lockup is "OFF" The SPDT switch
would need to be one side N/O and the other N/C.
The normally Open side would feed 12v to the light when activated and the
normally closed side on the brake circuit to maintain continuity.


For those of you wondering what this is doing, ever been at full throttle and notice that as soon as you hit 3rd gear still at WOT your rpms drop about 400 rpm, well thats your tc locking up. The motors are rev happy and need those revs to produce HP, well this mod will keep that from happeneing and keep those revs up.

I also recommend that if you do this mod install a tranny cooler if your gonna use this alot. When your not in lockup your converter builds heat, higher HP and rpms with out lock up for a long period of time will build lots of heat, thats an A604 killer."

1998 dodge avenger 4 cyl AT
Mods are:
Not enough