4L80E Guru's got a question 1992 454 SS
 

Have a question for you 4L80E Guru's. I have a 1992 454 SS truck with 4L80E tranny. Truck has a 572" Big Block and running the factory 4L80E tranny with a Circle D 3200 converter. Still retaining the factory computer to control the trans, chip has been burned at some point previous to my ownership for the usual 454 TBI mods.

I see that when making 1/4 mile passes at the track I put the trans in D so as to not to make WOT passes in overdrive. I am not sure how the parameters are burned on the chip, but the Torque converter will lock up in 3rd gear about 5500 rpms.

I spliced into the TCC wire and put a switch to keep the converter from locking up, but notice when I hit the switch to kill the lockup the tranny will go into a " safe mode " or something not shift into overdrive after that unless I reset the computer. I have to disconnect the battery and reset the computer and then everything will operate as normal again.

My question is, will it hurt the tranny to make a full wide open pass with the lockup disabled? I don't know if the tranny is going into a safe mode when I break the connection to the TCC. I thought this might be an easy fix until I can find someone to burn another chip for me, but I don't want to risk damaging the tranny.

With the converter locking in 3rd gear I am going through the traps around 5500 rpms. I am not sure if its really hurting the run too much with the torque of the 572", but I would like to see what it will do without the converter locking up on me.

Here is a link to a Youtube video of the truck making its first pass and you can hear when the converter locks down on the top end.


Thanks for any help or advice
Floyd

Not sure on your issue but nice truck!

Everytime you break the circuit....Code 83 will set & the ECM will inhibit 4th. The TCC clutch in the (I'm guessing Circle D's cheaper line HP single disc) torque converter will not last long with that kind of torque applying at WOT.

Get a Dual Pole/Dual Throw rocker switch & a 15 ohm resistor & wire in a separate circuit to fool the ECM.

Get a good resistor with a heat sink like this.....

I cut the Tan/Black TCC wire and put a single throw rocker switch in line to break the circuit.

Can you elaborate on exactly how to wire in the resistor and dual pole/ dual throw switch. I am not exactly sure of how to do what you are suggesting of a separate circuit. I guess I'm a dummy, could you show me a diagram of what you are referring to ?

I meant Single Pole/Dual Throw.

Like this..... Only switch it with the key off. Don't run it for long periods of time through the resistor as to avoid ratio error codes, The resistor will get warm....Mount accordingly.

Attachment 718396

Okay, I will give that a try and see how it works. I appreciate the info and response. I need to find someone who can burn a new chip and tweak in the shift points and keep it from locking the converter in 3rd gear all together.