Mine was also a FFDynamic fan... hmmm, maybe it's just an FFD issue? Inadequate CFM like OhioVX stated.

I noticed my engine temp was creeping up on the interstate at 75 MPH cruising with the outside temp only in the 70's. I didn't want to chance keeping it installed for the summer and risk getting stranded.

I'd like to go back to a electric fan as the throttle response was noticeably better.