Advanced Engineering Tech - How does pinion angle adjustments help in terms of traction?

Just looking for an advanced explanation of how altering the pinion angles in the drivetrain increases traction.

It has something to do with how the axle winds up and twists as the pinion
drives the ring gear.

It's pretty complex when you have to consider what the suspension is doing
and weight transfer of the car.

I have no idea what sort of traction increases can be achieved with pinion
angle, but I would imagine it's pretty tiny for a street car set up.

Pinion angle affects the leverage placed on the axle housing/suspension at launch. When you first apply power the axle housing wants to rotate upwards. The angle of the pinion/driveshaft relationship affects how much leverage the housing has during this rotation. As the housing rotates upwards the lower control arms push against their front mounts which helps plant the tire. The torque arm attached to the housing lifts the front of the car via its front mount transfering load (weight) to the rear tires.
After the suspension is loaded the pinion angle should be near zero for the most effective transfer of power and strength. This also reduces any tendancy for vibration.
Cars with bushings in their rear suspension will deflect more and should start off with more downward pinion angle. This is adjustable via an aftermarket adjustable torque arm on an F-body. The best setup is probably a compromise on a street car depending on the tires you run. Too much downward angle can cause the car to vibrate when cruising at speed and acellerate u-joint wear.
This may seem obvious, but you must have some initial hook for your suspension to work. Stick cars are often easier to hook because you can adjust launch rpm to shock the suspension and make it hook. If you can't make your housing rotate at launch and work the suspension it won't leave well. This is a reason why some lowered power cars will spin the tires at the track when much faster cars are leaving hard on the same rubber.

Ladder bar and 4-link cars use a much shallower angle on their setup because their suspension deflects less, but its still important.

on the street, you can make a car hook by just adjusting pinion angle. i had Brian(Madman) here in houston set up a Random technologies torque arm on a previous f-body of mine, and that thing straight hooked. and that was with stock location LCA's. instant center is another thing to look at when thinking about traction. its why adjustable rear LCA mounts work. the lower the rear of the LCA is, the further back on the car the instant center is.

can adding a torque arm to a car that already dead hooks improve the 60' any?

take a stalled auto leaving the line at 3k, cutting dead consistent 1.60 short times, dead hooking, no tirespin. would adding a torque arm make the car any "quicker" in the first 60'? i believe it would help transfer tq to the tires better, as the factory tq arm is flexible and would tend to absorb tq as opposed to sending it to the tires. but if that's the case the whole adjustment issue wouldn't be needed, just a brace, more or less..correct? but i guess adding a better tq arm, resulting in more tq to the tires would demand more attention to the susp., resulting in the need for pinion angle adjustment to compensate for the possibility of overpowering the existing setup. anyone care to elaboratE?

but i guess adding a better tq arm, resulting in more tq to the tires would demand more attention to the susp., resulting in the need for pinion angle adjustment to compensate for the possibility of overpowering the existing setup. anyone care to elaboratE?

i'd think so. if the caar already hooks good, i'd think you'd have to find the sweet spot again with the pinion angle adjustment. with the stock arm flexing(which is eating a little power itself) ever so slightly, its allowing the pinion angle to change. it just so happens that the changes leaves it right where you need it to hook. i think you would benefit in the long run from an aftermarket arm.