Hi !
So, your stopping off at one of my favorite places in the world ... the Salt!
There won't be any racing going on. Speedweek is in the middle of August every year. This year Speedweek is Aug. 18 - 24.
Check out Speed Week's Sponsoring Organization Site
I noticed your headed to my old stomping grounds when you leave Craters Of the Moon.... the Tetons. I don't know what route you planned to get to Jackson. But...If you drive to Arco and then go to Mud Lake you can pick up Route #33 and it will take you thru Teton Valley with an awesome view of the Idaho side of the Tetons.
Then 33 will take you over Teton pass with another awesome view. Of the Jackson Hole country.
If your planned route has you driving hiway 26 out of Idaho Falls you might think of taking hiway 31 out of Swan Valley over Pine Creek Pass to hiway 33 at Victor and then hand a left (North) about 12 miles for a scenic view of the Tetons. You can then backtrack on 33 over Teton Pass.