Brake guys, check my math.

[flyinlow]

Stock Mopar floating caliper   2.75 inch piston  , 3.14 x R squared..... about 5.9 square inches


Wilwood  120-6815 4 piston fixed caliper  1.75 inch pistons  2 per side X 3.14 R squared.....9.6 square inches


So about 50% more clamping preasure?

[John_Kunkel]

When computing the clamping pressure of rigid multi-piston calipers you only use the area of one-half of the pistons on each wheel.....I know it's counterintuitive but that's the way it actually is, one set of pistons only acts as a backup for their opposites.

Floating calipers OTOH use the measured area minus a few percent for friction losses in the caliper-to-bracket interface.

[flyinlow]

Yea , that's what I was wondering about.  

[John_Kunkel]

The surface area of two 1.75" pistons is 4.81 cu. in.

If you read caliper specs on Wilwood's website they only count two of the pistons surface area in their specs. IE, they call a 4 piston caliper with 1.75" pistons a 4.80" caliper.

Bottom line, the factory 2.75" floating caliper has more clamping force than the Wilwoods. Some would argue that the two pistons on each side give a more even application of force on the pads but even that is debatable.

[flyinlow]

So I can only count 4.8 sq. in.

That means the stock Mopar caliper clamps harder than the Wilwood. Who would  of thought.

[flyinlow]

Thanks John,  I guess I need some Cordoba brakets to use the 11.75 rotors with stock floaters.