I've heard that when you shif the 700r4 automatic tranny manually through each gear(when drag racing/full throttle) it will actually cause a lean fuel mixture. Is this true, or will i run quicker e.t's by shifting it myself so i can better pick the shift points?

thanks in advance for the help.

 

I have the T5. But I just cant see how shifting an auto tranny manually can not hurt it.