low or high stall torque converter for towing

[CLT2005]

Now that I got things squared away on my engine and it's running great I'm wanting to do some upgrades to the transmission and drivetrain. I'm also going to install 4.10 gears to help out with towing my 5th wheel. Since I have 35's this should get it close to stock.

When looking at torque converters it seems like most people go with a stock to higher stall to help spool the turbo, but with my gearhead tuning I'm not having any lag issues with my powermax. I know that I don't want to go with a higher stall, but I've seen low stall (1,200rpm) advertised for towing.

Does a lower stall really help with towing, or would this make my daily driving suffer and create a lag issue? I'm looking into a new converter just to freshen things up since I have over 230k on my transmission. A full build is in my future I'm sure, but for now lower gears, a new torque converter and better transmission filtration is where I plan to start.

 

[junglejoe]

I've never heard of a higher stall converter for towing..? Seems that would be the last thing you would want.

 

[mandkole]

not sure why you'd want that... it would really build heat.

 

[CLT2005]

Ok, let me 're phrase... I don't want a "high" stall converter. I'm asking is there any benefit to the extra low stall torque converter vs the factory converter. Maybe my converter is just weak, but if I put my foot into it it seems to rev up to about 1,600 rpms before taking off like a rocket.

I'm going to upgrade to a billet converter, and just trying to understand if the low stall 1,200 rpm option would be better. I read that factory converter can stall to 1600 rpm. Maybe what I read was inaccurate and that is what is causing confusion.

 

[CLT2005]

"The Ford Power stroke Diesels' engine produces so much torque that the factory torque converter stalls as high as 2000 RPM. *Our torque converter stall at approximately 1400-1900 RPM, which is right at peak torque. *This torque converter will increase fuel economy, reduce transmission temperature, increase low-end power and top-end acceleration."

Any merit to this statement?

 

[junglejoe]

So an aftermarket converter will lock up sooner. That makes sense. 1200 rpms is really low! I'm no expert on "low" converters, but that's just 600 rpms off idle. Seems that would cause more of a bog??

 

[PsRumors]

So an aftermarket converter will lock up sooner. That makes sense. 1200 rpms is really low! I'm no expert on "low" converters, but that's just 600 rpms off idle. Seems that would cause more of a bog??

Stall and lock up are not one and the same. Think of stall with power braking. Step on the brake and mash the go pedal to the point the engine starts to overpower your brakes, that is getting close to the stall of the converter.

 

[junglejoe]

Stall and lock up are not one and the same. Think of stall with power braking. Step on the brake and mash the go pedal to the point the engine starts to overpower your brakes, that is getting close to the stall of the converter.

I know what a stall does.. I'm semi retired drag racer, :fustrate: It will never fully leave me I don't think. What does the lock-up part do? never fully understood that part

 

[PsRumors]

I know what a stall does.. I'm semi retired drag racer, :fustrate: It will never fully leave me I don't think. What does the lock-up part do? never fully understood that part

In a lock up converter there is an actual clutch that gets engaged (lock up) when certain parameters are met so as to get 100% power transfer through the converter.

 

[junglejoe]

In a lock up converter there is an actual clutch that gets engaged (lock up) when certain parameters are met so as to get 100% power transfer through the converter.

Ohh.. ok gotcha! Makes sense.

 

[Mark Kovalsky]

"The Ford Power stroke Diesels' engine produces so much torque that the factory torque converter stalls as high as 2000 RPM. *Our torque converter stall at approximately 1400-1900 RPM, which is right at peak torque. *This torque converter will increase fuel economy, reduce transmission temperature, increase low-end power and top-end acceleration."

Any merit to this statement?

Yes.

So an aftermarket converter will lock up sooner.

No, it will not. Lockup is computer controlled, not stall RPM related.

What does the lock-up part do? never fully understood that part

There is a clutch inside the torque converter. When the computer commands it the clutch applies and eliminates all slip in the converter. Input and output speeds are identical with the clutch applied.

 

[junglejoe]

Yes.


No, it will not. Lockup is computer controlled, not stall RPM related.


There is a clutch inside the torque converter. When the computer commands it the clutch applies and eliminates all slip in the converter. Input and output speeds are identical with the clutch applied.

Ok, so it doesn't "lockup" , it "engages". it IS sooner and seems it would cause the truck to bog.

 

[Mark Kovalsky]

The torque converter is engaged any time the engine is running. The term you are looking for is "stalls."

 

[CLT2005]

Thank you for the info, I'll probably go with a billet Converter using stock or slightly lower stall.

 

[CLT2005]

Also, as far as different years/versions go, was the 5r110 upgraded throughout its production?
Could I use a transmission out of a 6.4 in my 6.0 if I were to buy a good low mileage transmission with warranty?

 

[sootie]

yes and yes. you will need the correct TC for whichever engine you are putting it behind.

depending on which revision-you may need to swap pans

 

[CLT2005]

What were the main upgrades done?

 

[Mark Kovalsky]

The gear train was made a little stronger in '05, and again in '08.

There was only one pan change. It was a running change in 2008. The internal filter was greatly improved and the pan was enlarged a little bit to clear the new filter. The newer pan won't be a clearance issue in any year truck, the change is not huge.

At the same time the external bypass filter was eliminated.