Lockup or Non-Lockup

[wcardoc]

I am going to be putting a 2004r in my Camaro behind a 475 HP small block. My question is, do I go with a Lockup or Non-Lockup trans?
A recent article in Super Chevy quotes one major trans builder as saying he doesn't like to use Lockup transmissions. The author agreed. They state that there can be problems with the trans locking in and out repetedly at highway speeds.
Any thoughts on this out there?

[Steve Chryssos]

I prefer lock up, but then again, everything we do is electronic where lock up is controlled by the vehicle speed sensor. Lock and unlock are both controlled by mph.

[6'9"Witha69]

Go lockup if you drive more than half and race it less than that. I have a lockup in my car and wouldn't want it any other way. If the TV is set up properly you shouldn't have cycling issues at hwy speeds.

[megaladon6]

and you can always use a manual switch to lock it up (it'll even lock it in 3rd and maybe 2nd gears)

[Steelrat]

and you can always use a manual switch to lock it up (it'll even lock it in 3rd and maybe 2nd gears)

Just so I inderstand manual lock up vs automatic. If you were at the track ( or down a safe deserted country road) with a manual lock up, does that mean when you hit 2nd gear you flick the switch, or flip it prior to launch?
Not real clear on the lock up concept

Thank you.

[vp23271]

They state that there can be problems with the trans locking in and out repetedly at highway speeds.

I went with a lock-up on my 700r4 from Bowtie Overdrives and liking it.

Out of curiosity, can some more knowledgeable forum members comment on why a trans would lock in and out at highway speed. Could this be caused by picking a torque converter with the wrong stall speed?

[6'9"Witha69]

I went with a lock-up on my 700r4 from Bowtie Overdrives and liking it.

Out of curiosity, can some more knowledgeable forum members comment on why a trans would lock in and out at highway speed. Could this be caused by picking a torque converter with the wrong stall speed?
Simply, it shouldn't. Once in OD the only way to unlock is via interrupt (from hitting the brakes) or shifting into 3rd. The constant downshifting is a different issue and goes to line pressures and TV adjustment as much as anything else. Stall makes no difference during lockup. There is essentially no stall.

[MJ_Bone]

I went with a lock-up on my 700r4 from Bowtie Overdrives and liking it.

Out of curiosity, can some more knowledgeable forum members comment on why a trans would lock in and out at highway speed. Could this be caused by picking a torque converter with the wrong stall speed?

It's not caused by the converter stall speed. IDK what kind of controller you are using but on late model f-bodies still using the PCM to control the trans, some guys have trouble with lock up due to the pulse width modulation (PWM) technique that the PCM uses to gently apply lock up. I think the fix is to delete PWM.

Possibly, a more simple cure is to install a lock-up switch.

My converter lock up works great with the Compushift controller. Programability options are locking in 3rd and/or 4th gear. It makes the high stall converter much more tollerable and the car more fuel efficient when making the 100 mile journey to the drag strip.