I am new to photography and recently traded a 5th scale car for a nikon D4 with a tamron 28-75 lens. does anyone knwo the appropiate camera settings to shoot 5th and 8th scale on road?

thansk in advance,

VG

you would want to use the sports setting for the camera, which will stop the car in the scene.

Putting the camera in shutter priority mode is usually quite good for action.

To freeze RC cars you will need a shutter of about 1/500th of a second at minimum (depending on the class and camera angle this could be lower or higher), Aim for somewhere around 1/800th to 1/1600th if there is enough light around.
Panning shots can be done from 1/20th and upwards, this is useful when there is not much light around and you don't want the camera to automatically put the ISO up too high which will cause the images to be very grainy.

If you want to go full manual, set the f-stop as low as your lens will let you (within reason) , then choose a ISO, if you don't have a telephoto lens and you will be cropping your photos, 500-640 is about the maximum i would use. Then using the light meter in the viewfinder, set the shutter speed according to that.
This should get you in the ball park, light meters aren't perfectly accurate(might adjust to the wrong area), so you may have to adjust some settings if your shots are coming out overexposed or underexposed.

Assuming your lowest f-stop is f5.6 i would start with these setting
-ISO 400
-Aperture f5.6
-Shutter 1/1000th
Choose and one setting and make it your variable to change as the light changes, Id choose shutter or ISO, you just need to choose what is more important

-Frozen motion
-Depth of field
-Low amounts of visual noise for using high ISO

Have fun!!

Josh