I have an automatic 1997 bmw 328ic with sport mode on it, when I do doughnuts (which already are **** because I have an open diff) and I hold the gas pedal all the way down with asc off and I start spinning, after like 1-2 minutes it’ll start losing power and the revs will drop until I let go of the gas a little and then floor it again, does anyone know why and how I can stop it from losing power?