Hey there guys. So what I want to know here is are we talking about doing a tranny upgrade with upgraded step by IPT or Levelten for the reason of purely being able to handle more horsepower and torque?? Or are we talking about doing this for that mainly but also being able to get more of that fly wheel generated HP to the actual wheels. I have a 330Xi with $15K in just the engine work alone and have long since contemplated doing this with my step, but it wouldn't be fore handling more horsepower just for putting that 340HP more to the wheels, instead of losing 100 of it to diastolic loss. I know that each time in physics when you re direct power so with an AWD another differential as well I will always lose around 15% or so, and with a slush box with a step around another 15% .
So how much more power from fly to ground can you get with a step upgrade?? That is the question. Our trans case for Xi's are from X5's and can tow, so they can handle over 2500 ft lbs of torque on the case, now the box etc. is rated tops around 340 HP, so that is a problem!! For me I am right at that level, tracking a few times a year and no issues yet. Ok let me know guys. I await anxiously.