Do the high stall converters lock-up below the stall speed?

[SIZEMOREMK]

Maybe a dumb question... but "they" always say that you should pick a stall speed lower than the typical cruise RPM. So if your cruise is 2500 RPM on the highway, you want a 2400 or less stall speed....

This of course contends with selecting a stall speed x RPM before peak torque.

I am assuming that on the lockup style converters, when the converter locks, it locks if the stall speed has been reached or not?

I am assuming this is why the 3500 stall is quite popular with our cars.

Can someone confirm that once locked, the stall speed is irrevelant

Thanks!

[ctrlraven]

You want your stall speed to be just about where your car comes alive at.

3500 is great for an NA car with 4.10 gears as the motor makes most of it's peak power above 3000 rpms.

I've had a 3500 for several years being NA running 3.55 and 4.10 gears. Granted it does take a little more input when driving on the street if you are driving normal, but if you mash the gas or pre-loard/flash the converter it will go. For me I required a re-tune when, if I got another one I would probably go with 3000 but with a new built motor going in, 3500 might be more ideal for it than to my stock motor.

Yes once locked stall speed is irrelevant.

[fastblackmerc]

Call the guys at Precision Industries for recommendations.

[tbone]

My stall is 3000 and I feel it's a bit high for everyday, normal driving. But get on the throttle and it's perfect. That's the point of course.

My converter locks at a little over 40 which is programmed in the tune.

I went back to the stock converter in between trans rebuilds (when I went through that nightmare) and hated it with a passion. Absolutely pathetic compared to a higher stall performance one.

[justbob]

Silly torque converts. I convert torque with my left foot!


Self proclaimed Builder Of Badassery.

Buy it, Break it, Build it BETTER.
"Since 2004"

[Limited360]

Silly torque converts. I convert torque with my left foot!


Self proclaimed Builder Of Badassery.

Buy it, Break it, Build it BETTER.
"Since 2004"


This is winning...

[SIZEMOREMK]

My stall is 3000 and I feel it's a bit high for everyday, normal driving. But get on the throttle and it's perfect. That's the point of course.

My converter locks at a little over 40 which is programmed in the tune.

I went back to the stock converter in between trans rebuilds (when I went through that nightmare) and hated it with a passion. Absolutely pathetic compared to a higher stall performance one.

So with 3000 stall and 4.10s the low end acceleration is quite noticeable then? I wouldn't think 3000 stall would be that noticable vs the stocks 2600-2800 stall? But perhaps your roadrunner has a higher torque multiplication ratio below/at the stall speed?

I've read there's some significant differences between the torque multiplication factors among the aftermarket converters but I've looked at several sites and none seem to mention a torque multiplication factor/ratio as a spec.

Seems like some generic sources say 2 to 2.5:1 multiplication ratio converters are out there, but none of the converter companies seem to advertise this. I also wonder what the stock converters multiplication ratio is?

[MOTOWN]

Stall speed with any converter will vary based on how much HP is put thru it, A 3K stall for example will stall beyond that when that same converter goes from a 550RWHP car to one making 1K+ !

Multiplication ratios will also vary based on how/and what the converter is built for, there is no set standard for this, any stall manufactuer will ask a boatload of questions before they spec out a converter for you, i have a 3k tripple disc circle D, and for a street car i would not go beyond that, high stalls are better suited for the track verses street duty.

[ctrlraven]

Stall speed with any converter will vary based on how much HP is put thru it, A 3K stall for example will stall beyond that when that same converter goes from a 550RWHP car to one making 1K+ !

Multiplication ratios will also vary based on how/and what the converter is built for, there is no set standard for this, any stall manufactuer will ask a boatload of questions before they spec out a converter for you, i have a 3k tripple disc circle D, and for a street car i would not go beyond that, high stalls are better suited for the track verses street duty.
Completely agree!

You need to buy what's suited for you and your goal.

[JoeBoomz]

I put a 3000 in mine and though the power kicks in perfectly when the blower does, the car doesn't move much until you rev it to 3k. For street I still think would have been happier still with a lower stall.

[Blackened300a]

I put a 3000 in mine and though the power kicks in perfectly when the blower does, the car doesn't move much until you rev it to 3k. For street I still think would have been happier still with a lower stall.

I never experienced this with the 3K stall converter. I can let my foot off the gas and it would move off idle. It would also drive fine with minimal throttle inputs.

[tbone]

I put a 3000 in mine and though the power kicks in perfectly when the blower does, the car doesn't move much until you rev it to 3k. For street I still think would have been happier still with a lower stall.


That sounds like something is wrong. I guess it depends on what you mean by "move much".

[JoeBoomz]

Oh it rolls under 3k don't worry - but noticeably less than it did with the stock converter which has a lower stall. For city driving I liked a lower stall.

[tbone]

That's the trade off.

[Logizyme]

The torque converter clutch will lock the converter at crusing speeds and has little to no relation to stall speed.


Silly torque converts. I convert torque with my left foot!


As much as I love the manual transmission spirite, transmissions convert torque, torque converters convert torque, clutches do not. A clutch will never output a torque greater than its input torque, a torque converter will.

[345HP87SSAC]

I circle D 3200 in my 4L85E in my Aerocoupe. It locks in 4th and acts mostly normal in most conditions. It takes off from a start with no problems.

I have had other stalls that stunk on the street in a normal car, but his one is almost normal.

HTH.

[tbone]

So with 3000 stall and 4.10s the low end acceleration is quite noticeable then? I wouldn't think 3000 stall would be that noticable vs the stocks 2600-2800 stall? But perhaps your roadrunner has a higher torque multiplication ratio below/at the stall speed?


The stock TC is nowhere near 2600-2800. Not sure of the exact number, but I think it's around 1600-1800ish.

[MOTOWN]

The stock TC is nowhere near 2600-2800. Not sure of the exact number, but I think it's around 1600-1800ish.

Exactly! Agreed!^^^^^^^^^^

[Logizyme]

Stock on the 11.25 is approx. 2200-2700, generally 2400. Ford does not have a specification for stall speed, buy gives that 2200-2700 (I'm rounding) for testing purposes.

Want to test it? At a stoplight, put it in manual 2nd. Floor it and watch rpm. Rpm will jump up to 2400ish and stay there until the drivetrain catches up.