Tight vs Loose Torque Converters

[andyf]

I chewed it and tried to swallow but it came up. How do you know your driveshaft rotational RPM?

Driveshaft speed sensor.

 

[33 IMP]

While on the topic. -- The Guy at My trans shop wants to have a convertor made, (for My 306 - 370 HP Ford -- AOD transmission), with the damper removed. -- He says that "it will still be a lock-up convertor. -- Comments on this ? -- Thanks

Lock up converters are a whole different deal.

Hughes performance has a tutorial on lockup converters, episode #2, on you tube. Many others as well, all informative!

 

[Moparfiend]

Driveshaft speed sensor.
View attachment 932337

Right a new one for me!!!

 

[wyrmrider]

or use your speedometer and know your driveshaft rpm at certain speeds

 

[andyf]

Right a new one for me!!!

My dashboard has a driveshaft speed tach next to the engine tach so I can watch them both. I can also data log them so I know exactly how much converter slip I have in each gear. I also data log the line pressure in the transmission as well as the fluid temp. That way I can have an intelligent conversation with the transmission guy when it comes time to make changes.

 

[dvw]

With all the discussions and comments about "tight" and "loose" torque converter operation

I thought that the term was Stall RPM, or stall speed, defined as: where the engine rpm was increased (converters pump or impeller rpm) to the point where the converter's turbine section begins to rotate, with the stator locked to provide maximum torque multiplication.
BOB RENTON

Stall speed is often commonly rereferred to flash. Engine torque, weight of the vehicle, overall gear ratio, and the method used to hold the vehicle stationary drastically alter this number. Just because a converter flashes to 5000 rpm doesn't mean the engine speed (impeller speed) needs to go to that to move the turbine (trans input shaft). True flash will show as the rpm the engine falls to on a shift. I've driven 5000 rpm+ converters on the street plenty. With 4.10-4.30 gear they are quite tolerable. They don't overheat the trans fluid either.
Doug

 

[66Satellite47]

The Turbo Action 10" "tight" that came with my Satellite would flash about 5000 IIRC. I was a very nice street convertor that did just fine at the dragstrip. Thought I broke it, so got a Lupo Dynamic 9 1/2". Turned out I wounded the motor not the 10" convertor. The 9 1/2" Dynamic drives real nice on the street too, great at the track. Not sure what the Dynamic flashes at behind my 512 motor, I'd guess about 5200 - 5300 RPM.
As others have said the "stall speed" has many variables. The top convertor builders have a pretty good idea of how to match to a given combination.