Not too close to the frog. Better is further out, closer to the balance point where the hair can bend around the string more easily and grip the string. It is also easier to cross strings there because the bow is in neutral, not fighting you. Closer to the frog the bow works against you and string crossing becomes stiff and clumsy. In the upper half of the bow arm and hand movements become bigger and slower for the same change of angle between strings.
Starting with one note, say A on the G string, work out the length, weight and contact point that gives you a musical sound when minim = 170. The length might only be one or two inches at most, with arm weight resting on the string through the bow. Look down at the string to ensure that each note gets the same bow length and sounds evenly. Movements can be too short (= crushed) or too long (= scrubbed). Don't try and do off- or semi-off string bowing. Then work on simple exercises like (G A B A) 0 1 4 1, 0 41 4, 0 1 2 1, 0 2 1 2, 0 2 4 2, 0 4 2 4. Slower tempos and longer bows at first, to get articulation and timing clear between hands. Have your brain fully accept each task at each stage of increasing speed. Look for a sense of balance between the effort put into each hand but the right hand is the boss.. This helps guide my choice of length.
Remain relaxed and patient and speed will come. High speed is not a brick wall, mental or physical, that you have to smash through. My metaphor is a free-spinning bicycle wheel with no brakes that just gets faster without much extra effort or resistance. You just gradually spend less time on each note.
Does your conductor really want you to play this at 170?