the stall on my upgraded trq converter is pretty much the same as stock... big difference is the internal vains...The pieces inside the upgraded converter are furnace-brazed, which makes the converter stronger and more efficient. Under heavy loads like wot,the fins inside a stock non-furnace-brazed converter will flex. When that happens, the converter loses efficiency and less power is put to the ground, while an upgraded trq converter will put more power down under heavier loads like wot ...and i can def feel a diff now at wot

 

No way does it cost any peak power. If anything the ten pounds of rotating mass saved will help peak power a little.