jaredwayt

whats up guys, i am a big m6 guy and dont really now all that much about how converters lock, and unlock, i searched and didnt come up with the answer i am looking for so please help a guy trying to convert!

i was wondering from a 1/4 drag strip mile, would you want the converter locked or unlocked the whole time?

and from a roll race say 2nd, or 3rd, would you want it locked or unlocked to benefit the car?

if i where to control it with a switch, if unlocked is best, when would it be the best time to lock it up?

thanks for the help guys.

sleeperstyle

iTrader: (4)

unlocked the whole time for me- i don't think many people lock their converters during a run with the 4l60e's, maybe with turbo transmissions..

fwiw people lock it up at the top of 3rd (end of the run) to gain a little top end.

jimmyblue

iTrader: (11)

You need to have a torque converter clutch that's meant
for it, or it will be pretty unhappy. The locked clutch trick
I think pays off if you're just about to upshift at the end
of the quarter; then sliding the RPM back a bit will let you
finish harder. Maybe if the TCC will hold you can get some
more MPH from the efficiency as well. But a lot of converters
(like mine) are way too under-clutched to hold full power.
Then you just cook 'em, rotisserie style.

You can get converters that are built for that kind of capability
but you will pay extra (though, you will surely pay sooner or
later, for doing it to one that isn't).

jaredwayt

ok, so say if i was running a guy from a 2nd gear roll, i would leave the converter unlocked until it hit 3rd, and then lock it up, but who's to say it wont be already locked in 2nd?

fwiw im thinking about running a 3800, w/full bolton and a little no2

strokedls1

iTrader: (1)

You can set up the lock up in the computer with ls1edit or hp tuners. Lock up is set up as a combination of vehicle speed versus tb blade angle. I never locked up my converter over 70% tps. The clutch would not like that much power being put through it. You wouldn't want the clutch locked from a roll because it wouldn't flash up to the stall rpm. I just use the lock up above 60mph for effiency on the highway.

jaredwayt

great, thanks, yea i guess i will have to wait and see how it does when it gets tuned.

Automatics

If the torque converter is designed correctly, you would not lock it when racing, etc. The lockup can give you more top end on the freeway at WOT in the top end of 4th gear. Otherwise it is only good for the extra gas mileage, and lower heat at cruising speeds.