25THRSS

Is there a forced torque converter lockup on our cars at WOT? If so, what mph is it set to lock up from the factory?

Apeiron

The TCC unlocks at WOT.

vjo90RS8

iTrader: (1)

at the track i can feel the TC lock-up at around 85MPH in 3rd.

25THRSS

It's been a while since I have driven the car, but from what I remember there is a forced tc lockup. The bog is definitely present, but I can't remember exactly when this happens. I believe that even bone stock the TC lockup is a major disadvantage.

vjo90RS8

iTrader: (1)

yeah, i can feel that forced TC towards the end of my quarter mile run.

BMmonteSS

It's set to 80 or maybe 85 in the chip, can't quite remember it's been a while since I tuned a 746. Don't have a clue why GM did this, you would think this would be very hard on the lock up. Easily changed......if ........never mind I'm sure you guys know what I'm going to say

Red25thRS

ya sometimes when im goin down the track...it seems like mine locks up too...i have 3.73 and it feels like when i got it mashed in 3rd gear right at about 3k u feel it bog a lil and it doesnt go thru the band as fast.....or maybe my 305 is just junk and runs outta power hahaha....but nah..my 305 runs amazingly strong for havin roughly 155k on it...i can hit 14.9 if i launch right and i dont even have headers lol...ohh and that was before i corrected my timnig of 10 degrees retarded...so when it warms up we'll see what it does

dimented24x7

iTrader: (2)

Forced TCC lockup will be at 85 MPH with the stock chip.

dimented24x7

iTrader: (2)

Theres been some talk of the fluid circulation to the cooler not being very good with the TCC not engaged. That may be why its forced to lock up.

My old one quit working so I disabled the lockup. All the frictions, even the ones that didnt slip, in the transmission turned black from the heat... Teh thing was trashed anyway so it didnt really matter

BMmonteSS

I recently got some time to look through a GM engineering manual for the the 700-r4. I didn't have much time, but I did see that the fluid flow for the cooler does not have any valves in line that purposly shut flow off. I can believe that when the converter is locked their is more pressure available to push fluid through the converter, but I can't confirm that. I'm runnin a transgo kit and run my car with the converter unlocked all the time except for cruising down the highway, been like that for 30,000 miles, but it's hard to tell what the transgo changed.

dimented24x7

iTrader: (2)

The other thing that I can think of is the added heat from having it unlocked for extended periods of time at high speeds/loads really pushes the temperature up. As far as the cooler thing goes, having complete hydrolic schematics would say for sure, but people insist that thats the way it works in a 700.:shrug:

BMmonteSS

I also have a temp guage in my tranny pan, the only time the the temp gets above engine temp is running around town for long periods of time, even then I've never had it get above 200 deg on a hot day. I'm running a 2000 stall s-10 converter. I can't really tell if having the TC locked drastically cools the tranny off. It seems like whatever temp the tranny goes to it does slowly. Like it takes 15 min on the high way to bring the temp down and it takes 30 min of around town driving to even get the tranny up to engine temp.