4l80e TCC lockup options

[Sean Cooke]

Guys I run a 4l80e with a Jakes performance black box for manual shifting. The TCC is on a switch, I ordered a msd 8950 rpm switch and going to wire it directly to a relay. Therectically it should automatically lock my converter at the desired rpm point.
Anyone try something like this or similar?
What's your 4l80e setup??

[Sean Cooke]

Well I came up with a possible solution, I'm taking a class and all we do Is stare at wiring diagrams so I made my own

[hotrodneb]

8950 rpm seems awful high for TCC lock. Typically the PCM locks around 45mph depending on conditions.

[Vegas 69]

8950 rpm seems awful high for TCC lock. Typically the PCM locks around 45mph depending on conditions.

8950 is the part #

Re: the diagram. I don't think you need the relay. just switch 12v to the tranny TC lock up

[Sean Cooke]

8950 is the part #

Re: the diagram. I don't think you need the relay. just switch 12v to the tranny TC lock up

The signal that locks the tcc is negative, the relay is the only way I know how to convert a (+) signal into a ( -) signal
This also always me two have more than one source to trigger the same unit. In the event I'm crushing on the freeway and want to override the 3k lockup

[Sean Cooke]

8950 rpm seems awful high for TCC lock. Typically the PCM locks around 45mph depending on conditions.

Sorry for the confusion #8950 is the MSD part number for the RPM activation switch.

[hotrodneb]

ok.....so now I get........lock at 3000 rpm...much better. Will it be a latching relay? Mine runs 1750 RPM @ 60 mph with 342 gears. Also how will it unlatch when you pull to a stoplight?

[Sean Cooke]

ok.....so now I get........lock at 3000 rpm...much better. Will it be a latching relay? Mine runs 1750 RPM @ 60 mph with 342 gears. Also how will it unlatch when you pull to a stoplight?

The Rpm activation switch sends the signal at 3k and stops the signal anytime the motor falls below 3000.. at 80 mph I'm at 2800 -3000 with 3.73's my idea is to incorporate a second switch to activate the relay anytime I'm cruising on the freeway at a lower rpm

[andrewb70]

TCC lock up shouldn't be just RPM triggered, but based on load. So if you're at WOT you don't want the converter to lock because that will wear out the lock up clutch very quickly. Computer controlled automatics keep the converter unlock when there is load. As I recall the lock up table looks at both VSS and MAP to determine lock up conditions.

So let's say you are just cruising on the highway, the converter would lock to increase economy. If you want to pass, and get on the gas, your MAP values rise and converter unlocks, the trans may even downshift from OD to 3rd. Regardless of RPM.

I would rethink how you want to do this.

Andrew

[Sean Cooke]

TCC lock up shouldn't be just RPM triggered, but based on load. So if you're at WOT you don't want the converter to lock because that will wear out the lock up clutch very quickly. Computer controlled automatics keep the converter unlock when there is load. As I recall the lock up table looks at both VSS and MAP to determine lock up conditions.

So let's say you are just cruising on the highway, the converter would lock to increase economy. If you want to pass, and get on the gas, your MAP values rise and converter unlocks, the trans may even downshift from OD to 3rd. Regardless of RPM.

I would rethink how you want to do this.

Andrew

I thought about this too... when I talked to a couple of different Trans guys they said the 4l80e is strongest when in lockup. That lockup should be used as much as possible. I drove around for a few months playing with setup. Trans will not lock in 1st, only 2-4 & drives like a stick car when locked. My trans is completely manually shifted.