Moving the bar up hits the tire harder and quicker. It also doesn’t keep the tire planted as long.
Moving the bar down will hit the tire softer and slower. It also keeps the tire planted longer.
Lack of bite can be as simple as shock adjustment, too little front end travel or stuff binding up.
The biggest thing I see is being over sprung. On the stuff we are talking about, you need to be able to pitch rotate the chassis. That means do a wheelie.
If you are over sprung in the front, the chassis can’t transfer weight to the rear tires. The higher (stiffer) the spring rate, the more power is required to get the chassis to pitch rotate. A lower spring rate will allow the chassis to pitch rotate easier.
If you have a 100 pound spring, it takes 100 pounds to compress the spring one inch. It’s the same in reverse. You have to remove 100 pounds to get the spring to extend an inch.
If you have a 100 pound spring and it compresses two inches at ride height you know you are putting 200 pounds on it.
What if you drop the spring rate to 50 pounds? That same 200 pounds will compress the spring 4 inches. Now the vehicle is too low. So we can with torsion bars or adjustable coil overs raise the front back up.
We still have our 4 inches of compressed spring storing energy. And the reverse is still true. If you remove 200 pounds from the front end (like at launch) your front end will separate 4 inches, assuming you are not changing anything else like shock settings.
Once you get the front going too fast, you use your double adjustable shocks to control how quickly the front end comes up.
Works the same for the rear.