Yeah, the dif. is a chaincase in the EFI R vs. the Diamond Drive in the EFI. Supposedly the chaincase models have more top end. In any case, I have the 06 F7 EFI R and, yeah, it is fast as hell. LOL I don't know if it would beat an Apex, but it's fast enough for me. I've seen 114 on the speedo. It goes 0-100 pretty damn quick. The first couple rides took a little to get used to, going from a 603 lb. 90 HP longtrack sled to a 470 lb. 140 HP sled, handles way dif., have to lean on corners more, etc. But now that I'm used to it I love it, I'm real happy with it.
I know from first hand experience just how quick an F7 is, I rode from Glenwood to Sauk Center and back with guy who had one last year (28 miles one way) all ditches, and the only thing I had on him was top end (on the couple stretches we could open them up) and that was with a 150+ HP Ultra, the F7 is an insanely quick and fast sled!! If and when I jump ship I'm gonna have an F7 parked in the stable 
The apex has more power but firecat is much lighter, 4stroke versus 2stroke. So i know both are fast because i know people with both but i guess id lean on the yamaha too. And how far are they going???? drag racing lake racing top end???
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