Seeker1056

I have never used a lockup tranny before for racing or heavy street use - and I cant seem to find any reference to how to run a 4l80 under serious power like for drag racing?
does one let the tranny use lockup or do I tune it out so it wont go into lockup when under full power?
Full power being expected to be in the 700 hp range
thanks

wht/73

Race in 3rd cruze in 4th.
With the correct converter it can be locked up in 3rd at wot.

Seeker1056

so first three shifts are unlocked, and locked for fourth?

So many posts about slippage in 4th or OD and I cant imagine there is slippage when locked?

what am I missing?

98CayenneT/A

Ideally you want to go threw the traps at the top of your 1:1 gear which in a 4l60e / 4l80e that would be 3rd gear.
In a 6 speed manual that would be 4th.

Also it is your torque converter that locks not your transmission.

Are you asking what is a necessary setup to lock your converter at wot or are you asking about lock up converters in general?

I have a lock up converter but never at wot.

Ben Brenner

The stock PCM locks the converter after 4th gear, usually around 55mph or so. A single-disc converter lockup clutch isn't very strong, so locking it up under full power would be a very bad idea, especially in a lower gear. There are expensive (usually at least $1000) triple-disc converters that are made for full-power lockup in any gear, so you can set your controller to lock it up as soon as you hit 2nd or whenever you want. You'll get the most out of them if you are planning on using a pretty high stall converter already.

wht/73

No 4th gear!
From what I've read it will hurt sprag

1st 3 shifts then if you you have a multi disc converter you can lock in 3rd.

Seeker1056

I just have a single disc converter with 3200 stall
so it sounds like not using lock up at all then?

wht/73

Yup. Just for cruising