Internal Body Aerodynamics

[phantomjock]

rtj - Once again - "You made me look!"
You'll have to bring the receipts. I can't find a credible reference.
I did a dive on TOO many links to be convinced. - As we'd say: Prove me wrong!/Change my Mind!*

EXCEPT for one case. That would be; INBOARD brakes mounted to the CHASSIS.
In that circumstance the load would be transferred directly to the chassis and would have some impact.
Front brakes are largely located for chassis weight distribution (aft location better), cooling (a plumbing issue) and front/rear steer (the rack and spacing).

Now, I do have inboard brakes on the rear CV axles, so would like to see the analysis and be happy - or sad.
But for the front - I'm happy to have the calipers FINALLY mounted. Now to work the steering... It is currently rear steer and front mounted calipers.
So any dive/anti-dive is from the double-A Arms mounted to the chassis.

Cheers - Jim
*RIP: Charlie

 

[BBShark]

AI gave this, but I will try to find the full article.


“
The position of the front brake affects anti-dive because it changes the
braking force vector's interaction with the suspension geometry, specifically the location of the instantaneous center (IC) of the front suspension.”

That silver vet from Europe had this mod.

I'm not sure how the rotational forces due to braking would result in a linear force acting on the A-arms. My guess is that it's the same regardless of the position of the caliper.

If you think about the caliper as a coupling mechanism, the tire/wheel, rotor, caliper, spindle are one body, with rotational forces (during braking) countered by the upper and lower ball joints.

 

[rtj]

The disk has a force exerted on it opposite rotation, so the force on the caliper is opposite. This has a vertical and horizontal component. The vertical component depends whether the caliper is front or rear mounted.

I was hoping to find a paper on it, but haven’t so far. But, did find this.

“
berkeman said: Summary: Does the placement of the calipers make a difference for braking performance in sports cars? (like anti-dive characteristics under braking Would that be it? Front braking tends to lower the front (raise the rear ). Putting the calipers on the advance side of the disk for the front wheels seems to me that the situation would be aggravated, with the braking torque driving the frame downwards. Similar argument for rear braking.

Source: https://www.physicsforums.com/threads/placement-of-disc-brake-calipers-for-best-performance.979033/”

Seems to be a lot of different theories. Actually, AI gives opposing answers.

I had found a better physics discussion thread, and will keep looking for it. An SAE paper or other refereed publication would be best.

 

[rtj]

I’ve found numerous claims that the caliper placement impacts bearing load when braking, so they are positioned to reduce bearing load in high performance applications. But, this was posted on discussion boards, so again, may be speculation.