Brake Caliper placement off of spindle, Does it matter?

[TXCumtrensh]

I work at a shop, and the more and more different cars i dissasemble, the more i wonder to myself

Is there any sort of benefit to having the brake caliper mounted towards the rear of the rotor,

in comparisson to the front



Just wondering if there is ANY difference what-so-ever if using the exact same caliper, just mounted in a different position, if it would make a difference.

Discuss.

[eddiec]

i think not. mounted differently due to component locations.

[RyanAwesome]

lower center of gravity. though it is nitpicking. thats how formula 1 rolls iirc.

[AmoebAssassin]

No there is no appreciable difference for a street car -- the only pro is lower CG, as RyanAwesome mentioned, but this is only noticeable in racing applications.

The reason most cars have them rear mounted is that most cars have a front-mounted steering rack setup, meaning that the rack is mounted such that the tie rods attach to the front upright (knuckle) ahead of the spindle (the machined boss on which the hubs and wheel bearings ride). This means there is usually a protrusion from the knuckle, pointing to the front of the car, for the tie rod to bolt to the knuckle.

This creates a number of engineering concerns, the two most important being packaging issues (difficult to package a large caliper close to tie rods and tie rod mounting points on the knuckle), and stress concentration in the knuckle (steering forces and braking forces are both considerably large -- concentrating both steering and braking forces on one side of the knuckle leads to increased stress concentration in the knuckle and is generally poor engineering practice).

Thus, most manufacturers package their calipers across the spindle from the tie rod mount arm. Therefore, most cars with front mount steering racks will place the caliper on the back of the knuckle towards the aft of the car. Nissan uses rear mount racks for some reason, so the calipers are more often placed on the front of the knuckle, towards the fore of the car.

[eddiec]

mounted differently due to component locations.

[RyanAwesome]

He was just elaborating.

[Defiant]

Rolls-Royce either tested or actually used two calipers on a rotor, and found that more pads can't pull any more heat than one set can.