TC Stall Speed?

[TooMuch03]

So, I am gettinga new torque converter built with my rebuilt tranny. I haven't found awhole lot of difinitive information about stall speeds here, so I was wondering what kind of stall speed would be best, higher, lower, or stock? Or maybe not what's best, but what are some pros and cons of going higher or lower than stock?

[TooMuch03]

Any thoughts guys ?

[DoubleDpsd]

I read some good things over on psa about rcd's 6.4 converter having a 1600 stall and people with that converter were chiming in how much they liked it. I'd call jard @ rivercity for the breakdown.

I'm interested in info on this topic also, bump for ya.

[windrunner408]

IIRC I believe that there really wasnt any benefit of going with anything other than the stock stall. I would really like someone to confirm that for me but I do remember hearing that. I know if/when I get a built transmission, I am going with the stock stall speed. I definitely have not heard of any specific stall speeds that people have been raving about so I am inclined to think stock is still the best. Hope that helps.

[windrunner408]

Originally Posted by darsey715

I read some good things over on psa about rcd's 6.4 converter having a 1600 stall and people with that converter were chiming in how much they liked it. I'd call jard @ rivercity for the breakdown.

bump for ya.

Good call man. I agree. Give Jared at RCD a call.

[TooMuch03]

Well, I ask because the shop that is building my transmission (Automatic Transmission Design in Germantown, WI) has built a lot of transmissions for performance cars and trucks, including some pulling trucks that are owned by guys I know. And, they are recommending that I get a slightly lower than stock stall speed, which is 1800 I think, to help with drivability and towing. But, I have read a little that higher stall speeds should help with spool-up

I am going to go talk to them more about it today, but i just was looking to get some input/information for from you guys if anyone has been over this already.

[windrunner408]

I say screw it and stay stock. That's my story and I'm sticking to it.

[fordfan30]

A lot will depend on your turbo. A vgt should stay stock but a non vgt might benefit from a slightly higher stall I would think

[TooMuch03]

ok, so I talked more in depth with the guys at ATD today. They said that they like to build torque converters for diesels that are designed to be more efficient, the by-product of tightening the veins up will be that the converter stalls at a slightly lower speed. The idea is to get more of the diesel engines low end torque to the ground faster. They also build lots and lots of converters for drag cars with much higher stall speeds. I was told that the higher stall speeds make the converter less efficient, which would be less useful on the street, especially when towing. The drag racers apparently don't care as much about efficiency and are more concerned with being able to get the engine up into its power band before engaging. He said that stall speed is not very important at all with a diesel since the tuning is so flexible, and can be adjusted to make even very large turbos streetable. He said that the efficiency of the converter is significantly more important because there is so much torque and a highly efficient converter is needed to take advantage of that.

I just condensed a half hour conversation into a few sentences, so hopefully, I have paraphrased him accurately. This does make sense to me with my limited knowledge of torque converters, so I will let the experts work their magic and see how I like it