Once again, sounds like VVT overlap from the OFT tune.
Happens at 4s-5s, 7s-8s, 12s, a little at 24s, 38s-42s etc. right?
If you want to get rid of it you'll need to change your current tune to a custom map (you could pay Shiv at OFT for remote tuning work, he should know what to change to get rid of it which will likely result in some power loss in that 3.5k-4.5k range) or go back to stock. Don't believe me? Drain the tank, put 93 octane in it and flash back to the stock map on your OFT, noise gone. You can even flash to OFT's stage 1 map and hear it come right back. I believe most tuners say it is harmless, whether you trust that is up to you.
Once again in case you didn't bother to read it the first time I linked it for you.
http://www.ft86club.com/forums/showthread.php?t=59475