Previa sometimes loses power, smell burnt rubber

[f18cmech]

Hi all,
Need your help on an issue. Sometimes, randomly and for about 5 minutes of driving, the van loses about half of its power. Also, during hard acceleration or times like the loss of power, I can smell what seems exactly to be burnt rubber. Any idea what could be the issue?
Thank you...

[pdgizwiz]

Could it be that your supercharger belt is slipping, or that you supercharger is binding up (maybe run out of oil)?