Short answer:
Oh... I really don't know if your lenses can be useful for shooting a motorsport event, except, of course, in secondary, detail shots showing people on the side of the track etc. I'm afraid that you really cannot shot the race itself with these lenses except, of course, a very general plane with some cars in the middle.
Generally speaking, Your focal length(s) and AF speed is not enough to fully cover such an event.
Long answer:
When shooting action sports, action-stopping shutter speeds are usually a top priority (1/500, 1/1000 or higher). A specific example: I usually use 1/1250 (or faster) for soccer photography. A wide aperture is usually the key to get these fast shutter speeds. Outdoor sports are often played in bright daylight conditions where even f/5.6 max aperture lenses will work fine, but fast/wide aperture lenses are still a big advantage. Wide apertures can blur the especially distracting sports venue backgrounds and can yield the fastest shutter speed/lowest ISO setting combinations.
When cloud cover moves in or the sun is below the skyline, I seldom want a lens with a max aperture narrower than f/2.8. Even at f/2.8, very high ISO settings can sometimes be needed. And if you are shooting outdoors under the lights, you will probably think that f/2.8 is too narrow.
Getting the right focal length is, as usual, very important for selecting a sports lens. Many outdoor sports participants cover a wide range of distances from the photographer's position.
Professional sports photographers shooting big events will usually be using at least three camera setups simultaneously - to make sure that they have the right focal length available all the time. Probably two of those lenses will be zoom lenses. Zoom lenses are great for getting the framing right for each opportunity - and for delivering a wide range of views and perspectives. But, due to narrow aperture issues, The ultimate sports lenses with focal lengths over 200mm are prime/fixed focal length lenses - with wide apertures.
If you are shooting track and field, with full access to the venue, any focal length from 24mm through 400mm or even 600mm can be useful. But if shooting from outside of the fence or from the bleachers, you are probably going to want 200mm - 400mm depending on your subject distance.
Autofocus performance is a big differentiator between lenses when action sports are the subject. While most lenses can capture a distant subject running perpendicular from you across a field (a constant focus distance), it takes a good lens to be able to focus-track a fast-approaching or departing subject at close distances or with tight framing. Economy lenses will not typically be up to this challenge.
Image stabilization, a feature on many of the lenses I recommend, is not a big advantage for many types of action sports photography. The required shutter speed for handholding sports lenses is not usually a concern as the shutter speed required to stop action is usually fast enough to stop camera shake. IS is, however, a very useful feature that you might use for alternate subjects at an event (people in the stands, players on the bench).
Many IS lenses have a panning stabilization mode (Mode 2) available. You might find the panning mode helpful for certain action sports subjects - it is especially effective for capturing motorsports and other flat-track wheeled sports (cycling for example) with a motion-blurred background.
