[Hypsi87]

I know enough about this to be dangerous. It appears that stall and slip are two different things (I kind of have a hard time understanding this). There are efficient and inefficient ways to to make a higher stall convertor. It appears that the larger diameter the convertor the more inefficient they have to make it to get the stall. The convertor is a viscus coupler. Its trying to transfer power though a non solid connection. The fins of one side of the convertor are acting on the tranny fluid and that fluid then tries to "grab"/ force the other fins to move. Now it pretty much is easy to see that fin angles are going to affect how hard the one side pushes on the fluid and also how easily the fluid can transfer the power to the other set. Now from that you can see that there are efficient and inefficient fin angles. Now you got to start addressing the size of the convertor and the fins. Basically since where not solidly transfering the power we are going through (for lack of better words) some kind of squishy / flexing / twisting / slipping kind of deal. Well if your trying to pass lets say 500 hp through this deal it only makes since that a larger one will do a better job because its physically bigger and can handle the power better. Maybe like tires in mud. Tires with small tread blocks can grab mud but it cant grab enough of it to transfer much power. Now you take a nice set of big old mudder tires with the bigger tread block, its going to be grabbing much more mud and therefore do a much better job of transfering the power. This is where the big convertors down fall comes. It grabs to good so you got to put crappy angles on the fins to get the stall speed up. This same crappy fin angles makes the convertor less efficient and makes it slip. This slipping is a total waste of power. Its converted to heat which takes out your tranny, and slows your car down. Yes it allowed you to build boost quicker but then bit you in the ass the whole rest of the track. Now your smaller diameter convertor can use better fin angles more more efficient power x-fer, but they will still stall because like the smaller tires they can't grab enough. This is the better of the two senerios. You can start running into problems if the convertor is too small because even with good fin angles it just its just too small to try to x-fer that much power through it........

I have too much time on my hands

Andy