Front Fork Spring Advice ...?

[fallzboater]

It used to dive every time I hit the front brakes but it no longer does.

But isn’t that what the suspension is supposed to do? The greatest load on the front end is hard braking; you should expect near or full compression under hard braking. Otherwise, what is that suspension travel for? You are not going to be creating a larger load via a bump in the road than you will be by braking.

On the street, I don't think you should be too close to using the full travel just under braking (usually <1g max). Bump forces can be significantly higher than 1g. This can happen from the inertia of the bike in a g-out (dip), or hitting a bump that's near the height of the (remaining) suspension travel. Bottoming is not good for traction.

On the track, the surface is usually quite smooth, so the bikes can be set up to use most of their front suspension travel under braking, or full cornering g's. You can definitely see this in pictures.

Good damping is important, too. If you've got enough low-speed compression damping in the front (and rebound damping in the rear), your bike won't seem to dive on the brakes, even with fairly soft springs (and vice-versa for squat under acceleration). On the other hand, too much high-speed damping will make the bike feel harsh and is not good for traction. Most stock suspension is too soft on the low-speed, and too harsh on the high-speed (and the spring rates are whacked).