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Discussion Starter #1
Anyone know what speed the converter locks up at?

I still don't fully understand how diesel converters differ from gassers, maybe someone could shed some light on that as well for me.

Thank you.
 

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The converter locks up exactly when the tcm tells it to and not before. The rest of your questions have been explained and rehashed for years here. Do a serch.
 

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stall speed and lockup speed are completely different...which question are you asking?
 

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Discussion Starter #4
so then what exactly is different about the 1057?
 

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I'll take a crack just to see if I am getting any of this....

1057 has a higher stall speed (say than a 1050) and a more efficient fluid coupling stage. That means when you are not locked the converter will transfer energy between the engine and the trans better and more quickly (more grab?). It also means that the higher stall speed will continue to transfer engery (and not turn it into heat) in fluid stage higher into the RPM range. Where a lower stall speed converter will stop transfering energy at a given RPM and begin to make heat - the 1057 will continue to transfer power to the rest of the trans/wheels while in fluid stage.

That is how I have understood it but I could be totally wrong or backwards.
 

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A diesel converter really dont differ from a gasser.....I mean it acts the same in the fact if you put a converter in a stock 305 gasser and then throw it behind a built 350 it will perform much different. Thats why I hate how gassers have thier 3500 stall rating etc:rolleyes:

Also each converter will be differnt through the range not just what it "stalls at"

What exactly are you fuzzy on?
 

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1057

Unfortunately the word "stall" has become the by-word to describe torque converters. This evolves from the fact for years & years this worked as a generic term when applied to GAS torque converters. Even then not all "stalls" were created equal. Raising stall can be achieved many different ways, some right and some wrong.

Generally higher stalls equate to higher STR (stall torque ratio) or the multiplier used to determine torque multiplication. Lower stalls have lower STRs' and this adds to the confusion when applied to diesels because no mfg wants to truthfully state " our converters are more efficient and have a LOWER torque multiplication" however this IS the case, and its really OK to a degree. Lower stalls and higher efficiency equals lower STR, and this is OK to the degree the stall does not become so low that the engine does not have enough rpm to produce enough exhaust to spin the turbo to build boost to make power.

Diesels generally share two common characteristics, max-torque (lots of it) developed at much lower rpms than gas engines and they are turbo charged. Because of the big torque #s' diesels do not really need a higher str but benefit from increased efficiency to deliver the high levels of torque they allready have to the ground. The trick is to design the converter so that you have max fluid coupling and yet still allow turbo spool on the low end. If a mfg advertises that their more efficient-lower stall has more or increased torque multiplication you have to ask the question . More than what? The 1057 is the result of Sun Coast's effort to provide a more efficient fluid coupling and retain good low-end spool up benefits. We have accomplished that. We are and always will be looking for ways to make it better.

There are many ways to manipulate clearances, fin angles, and stator design to achieve different characteristics of converter function.
We can spend a lots more time (that I do not have at present) discussing this subject.
Smoop
 

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Excellent writeup, Smoop :ro)
 

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Discussion Starter #10
thank you smoop, I understand now and that did answer my question. I appreciate it when a vendor can get on here and explain their product to us lay people and the point is understood. Also I tend to give more respect to a vendor when he/she can explain their product with out slamming a competitor.

Well Done :thumb:
 
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