I know this is something that's been discussed at length in various forums, but, here we go again...
Most people say it can't be done. Some people say it's because the motor itself is made from such lightweight materials that it can't withstand high (or even ANY) boost. Other people say it's because the N52 has Valvetronic and they couldn't get it to work properly with forced induction.
Now, excuse my ignorance, but I believe the current M5 has an engine that has Valvetronic and uses twin turbo charging - the S63TU I believe is the engine code. Surely Valvetronic wouldn't be the culprit in trying to boost an N52, any thoughts?
