Anyone here shoot motorsports with an XT-2? I shot an event (HPDE circuit) a few weeks ago using my XT-2 and the 100-400, I had the shutter speed locked to 160th and iso locked to 200, but left the aperture at auto. It was a bright day so most of the shots ended up around f/10-f/14... I had the camera set to continuous auto focus (single point set to the largest) with the auto focus mode left on 1, and drive mode set to 8fps... I was also using the 95mb/s Sandisk cards...
It was the first time shooting motorsports with my Fuji gear and regrettably I didn't think to take along the battery booster grip. I found my frame rate dropped in times I didn't expect it to... I know it probably can't compare to my experience with the 5D3 and 100-400mkI, but I felt it the XT-2 could have done a little better... This is by no means my normal genre so I don't expect to have the perfect setup for this type of shooting. I mostly shoot wildlife with the 100-400 and even landscapes believe it or not. Shooting birds in burst does feel the same as shooting a fast moving car and I feel the Fuji system does fine for shooting birds...
I had bursts of 8 frames and didn't experience any slowdown (where it felt I could have kept the shutter pressed longer), but I also had times where it felt like I could barely get more than 3... I am thinking the autofocus might have been the issue, but unsure as it didn't appear to be hunting...
I am going to shoot another event in the fall and debating if I should invest in the faster UHS-II cards. But I am not convinced the cards I have now are the bottleneck.
The "barely get more than 3" moment" was this after doing a long burst? I'm not sure if my 5dmk3 or 5dmk4 has deeper buffers if you rattle off many actuations. Also the 5dmk3 is rated 6 fps but it's not really intended to be a sports camera.
The XT3 is definitely where the XT2 should have been as far as AF speed/body performance. The X-t2 is good as far as a Feb 2017 body but the September 2018 release of the X-t3 is a refreshing fast body.
The Sandisk extreme pro UHSii writes 260MB/s vs the your current card of 90MB/s. If the buffer isn't filled the card "might" be the bottle neck.
Using my X-t2 at the ice rink with my kids I documented my youngest skating for the first time. My 50-140mm combo worked well be I even felt a sluggish lag at times. I'm also using the same Sandisk SD cards you have. Oddly later that month I used my Sony A73 with Gmaster 70-200 and it just didn't slow down at all using identical SPEED SD brand and speed cards. I think the body, in body processor and slower cards collectively made your experience sluggish.
In your area there maybe a "Fuji Try and Buy" program where you can borrow a body/lens for 3 days for free. Your next event I'd suggest looking into such programs and use the xt3 as an actuation pig during your next event and see how the X-t3 performs vs our aging x-t2.




Hope all works well on the day.

