[TransamGTA350]

It sounds like you just need to slow down with your shifts. There’s no need for lightning fast shifts on track. 3-4 or 4-3 are easy to do quickly. 2-3/3-2 or 4-5/5-4 are easier to miss a gate, so just be deliberate, do it a bit slower and make sure you’re in the right gear before letting the clutch out. You’ll never money shift if you do that.