you would need to check with the supplying dealer, sometimes if the are not very good they will try to void you warranty if you do not use HD oil, my dealer here has fitted Short shots, a fuel pak and a KNfilter and not voided the warranty.
I just extended my warranty and I talked to the service manager. Before I bought it I asked him if my warranty would be voided because of my Sampson pipes and stage 1 (Big Sucker). He said NO!
Funny thing here is that if you called a bunch of dealers and asked the same question, you would get mixed answers in return.