Depends on power level type of tire. weight distribution power level. The lower bar on a bias slick will probably be some where close to parallel with the ground. The upper bar will be pointed down in front to intersect the imaginary extended length of the lower bar some where around 40-45" out. the spread of the bars on the brackets makes a difference.
This may help you. https://www.youtube.com/watch?v=nU4PXWg2Dg8
Doug