after dark

iTrader: (5)

When choosing a stall converter what should one go with? A lock up or non lock up? Does the lock up stall all the time? Why and what for on either.

Some say lock up, and some say non lock up...I am new here and sorry if this has been asked before. Thanks in advance

TA TECH

iTrader: (8)

Ya want a lock upconvertor, it will have over drive then and it will unlock when ya need it! A non lock up would be a pain in the a$$ trust me!

ack5005

iTrader: (3)

You definitly want a lock-up! If you can use one on your car then get it. If I didn't have a lockup on my converter I would probably park the car until gas goes down. Basically the lock-up keeps your car from drinking all that precious gas you put in it. When you get over 40 or so your RPM's will drop as if you're in another gear. Kind of like having 5 gears in your auto.

after dark

iTrader: (5)

So is the non-lock up for drag strip only and not on the street? When I stomp on it the lock up will unlock baiscaly becoming a non lock up...right? How much will the RPM's drop when it locks up? If it's a difference of 2-3 hundred rpm's then I don't see what the big deal is.

monicaz28

iTrader: (5)

Right, if you get a non-lock up converter, then you are going to be driving around in normal traffic with the rpm's way up ALL the time.
With a lock-up converter, it will drive like normal at a certain point... 45-50 mph is about when mine locks up..
and yes, when you hit the gas pedal, it will unlock.

monicaz28

iTrader: (5)

Oh, and no, it's not the difference of 200-300 rpm's...
Example:
I'm driving like normal, as I am accelerating easily (not really putting my foot into it), the rpm's are around 2400 like all the way up to about 45 or 50 mph and when the converter locks, they drop to like 1200 or 1300.

12secSS

iTrader: (30)

You car has a lock-up unit currently, based on you sig. The reason for lock-up units is for fuel mileage increase over a non-lock-up unit. It is a clutch, like a manual, inside the torque converter, it allows the vehicle to free wheel until a certain MPH is reached, then it will lock. It only locks at speed, otherwise it would stall the vehicle, just like a manual. The rpm difference between the unlocked and lock status of the converter really depends on the efficiency of the converter at a given rpm point. The size and STR play a big role in that. So you could have about 700 rpm difference at low speeds with a stock lock-up converter compared to a 2500 rpm difference at higher speeds with an aftermarket unit. The difference came make a huge difference in gas mileage, based on how you drive.

after dark

iTrader: (5)

Thanks everyone. Gas milage is kind of out the window when you start hod rod'n your street car, right. I have a Yank SS3600 in my GTO now (with a cam) and I don't like it, it seems way to tight, I plan on going with a bigger one like a 4500 . Just trying to make a choice on which one...Thanks again

monicaz28

iTrader: (5)

Well, I've got a 4200 and I like it...
With my mods, I get about 10mpg.

after dark

iTrader: (5)

I find that the lock up converters I see for sale are modified factory converts. They just cut and bend the fins to make it stall higher maybe in a 9 to 10 inch. On the non lock up it looks like the good stuff is used, maybe in a 8 inch converter. How is efficency defined? Does kick *** parts meen great efficency?

Ragtop 99

iTrader: (7)

Put a Yank YTP 4000 or 4200 in there. You'll notice some serious gain over the SS3600.

12secSS

iTrader: (30)

Efficiency is defined not by the parts selection, but by how high the input shaft rotates (engine rpms) versus the output shaft (trans rpms) and how quickly it can make the output shaft "catch up" to the input shaft speed.