When my Viking Exhaust arrives I'll try some of the tors, RamAir downloads but I hate popping. To me, backfires means your bike isn't tuned correctly. This said, most motorcycle manufacturers retard the timing in their bikes. And over the years I've installed may TREs in different makes and models along with intake and exhaust upgrades and I've never fought decl pops like I had on my 09 rocket. However, back then there were active members who would help. They would take the tunes and tweak them and make needed adjustments. Apparently they've moved on. So, I too might have to invest in a PCV for a good fual/air mixture and tune. I don't want to but it's my bike. My problem.