CONVERTERS: lock up vs non vs confusion

[timewarped1972]

ok guys, i see alot of stuff on converters but i still have some questions. ok 1st, on the stock converter, when does it "lock up " and in what gears does it lock up? is it in all gears at a certain rpm or what? and what about od, is it always locked in od?
ok here's my deal, i ask because i see people recomending or getting non lock up converters and i understand why, but, just cruising i still turn relatively low rpm's and thats in d, not od even. so, i know if i do get a stall someday i cant get a real high stall because i don't want it slipping like a muther.....
but then i see the aftermarket " performance lock up converters" and so i thought maybe that would be a good compromise but don't know if those make enough of a difference to bother with. not to mention i do want this car capable of road trips so i'd like to atleast have what ever i'm running locked up when i'm in od......
so any help or technical info on what locks up when and in what gear at what speed would be appreciated......

 

[393Bird]

The amount of differance in RPMs at cruising between a lock up and a non-lockup is less than 500 rpms. The lockup AOD has lockup in D and OD. The Non-lockup will pull stronger since you still have torque multiplication in 3rd and OD. The other advantage is the Non-lockup can use a 1 piece solid input shaft, which gets rid of the major weak spot.

I am running a non lockup, with a 3500 rpm stall on the street. It is a little much for most, but it pulls like it has 100 HP more. I am using two 24,000 GVW B&M trans coolers to keep it from getting hot in town.

 

[90mustangGT]

A lock up will activate the TCC (torque converter clutch) at cruising speeds durring low engine load so the engine will be directly connected to the trans and will be better for a daily driver and better on gas milege. A lockup will be just like the factory converter while cruising, but will perform just as well as a non lockup durring launches.

 

[shttygtstang]

dont go with a high stall for the street 3500 is more than enough for the street i have 4000 stall and im regreting it

 

[timewarped1972]

it remains locked in 3rd regardless though right? or just in 3rd as cruise speeds? regardless, i think a performance lock up is what i'll be lookin for for my application. if i can get it to rock in 1st and 2nd i can live with less in 3rd......i see b@m makes them but some say stay away from b@m. is that for the lock ups as well or just the regular stalls? who makes an affordable lock up stall? or i guess i should say the cheapest yet good converter.......my shift kit is on the way and after that it's either gonna be a converter or starting with the engine bolt ons....

 

[WantaGT]

i just bought a TCI lock up, i got the street fighter. it's good for 1500 rpm above stock. yeah it's a little loose but i'll grow into it

 

[ponyboy19]

I have the Mild Street Edge http://edgeracingconverters.com/index.htm it's a 2600 stall that flashes out to about 2800 and is said to reduce heat by about 10% if I remember correctly. Call Andre and he'll set you up. So far I really like mine especially for the price. I was told the convertor is built so that you really don't need a hardened imput shaft because it can't bottom out. It's worth checking out IMO.

 

[davs5.0]

Definately check into the Edge line of converters. Awesome piece of equipment. I went with the 3000 9.5" lockup and it made a HUGE difference in my times. I needed to install some Et streets because the street tires were useless at the track. Car felt like it picked up 100 hp. The difference in power multiplication at the track was unbelieveable. With the stall and the et streets, I dropped over 1.3 seconds in et with no mods to the motor.

It by far was the best thing I did to the car.

 

[90mustangGT]

it remains locked in 3rd regardless though right? or just in 3rd as cruise speeds?

No, it will release when you put the gas down. Your stocker does it. EX: your cruising on the highway and you put the gas down and the rpm rise but you don't quite downshift, then when your just cruising again the rpm drop a little but you didn't change gear. Hard to explain but that's the TCC engaging and releasing.

 

[timewarped1972]

kinda stays locked when maintaining speed but not under accelleration, it sounds like. as long as i can cruise in 3rd and od with out it slipping then i'll be happy........by the way, my shift kits on the way, i went and bought tranny fluid....is mercon v ok??? they had dex 3 with mercon and it said on the mercon v it would work for mercon applications. there's so many types of tranny fluid it's about sick.......

 

[Nottoofast50]

Mine doesn't do that.....

 

[393Bird]

An AOD itrans lgoes in to Lock up in 3rd and OD. If the load increases in OD, it will down shift to 3rd, but stays locked. If in 3rd and load increases, it will down shift to 2nd. The AOD does not lock or unlock depending on load.

For a daily driver a lockup converter is the best choice, since it will provide better gas millage, and allow the transmission to run cooler. For a weekend play car, the choice is not so clear. If you are going to use a non lockup, make sure you add a transmission cooler, since the one in the radiator will not be enough. If it is mainly for the strip, and is over 3,000 lbs, the non lockup is the best choice, since it will provide a much stronger 3rd gear pull.

Here is a dyno graph of a car ran with a lock up, then a non lock up conveter tested the same day.

Below 5,400 rpms, the non lockup has much more torque, and more HP. The farther above this rpm, the lockup converter starts to have the advantage. Since the AOD uses lockup in 3rd and OD only, you would only see the differance in 3rd gear while racing.

 

[timewarped1972]

makes sense. thanks for posting that graph too.........i definatly thing a lock up would be for me as my goal with this car is to get performance out of it be remain as streetable and simple as possible. 1st and 2nd is where it will really need the stall anyway. i see some get a 3000 lock up and they say it's loose but tolerable. i assume that means it's great when you stab it but 1st and 2nd are a little mushy when your just barely into it.........

 

[90mustangGT]

Thanks for some clarification 393bird, your the man!

According to that graph the lockup is better for top which makes sence because less power is being "slipped". I know a tq converter turns rotational energy, (power, kinetic energy) and turns it into torque (potentail energy). So it all makes sence, unlike my spelling.

There are devices which you can controll when it locks up and when it releases, sounds like a worthy investment, what do you think?

 

[Qwk88LX]

whats the difference between a 24 & 26 spline converter & how do I find out which one I need?