///Rage said:
peddy said:
I've heard they're good considering the price you pay. What are you going to get on the rears then? 286 or 304 discs?
Ill see what they recommend...prob 304. My understanding is that rear brakes are less important since im less likely to be trail braking
Stupid question but do more pots = larger caliper size or just more even 'bite' ?
On hold again... so, found this:
Most of the aftermarket performance brake kits use fixed calipers rather than floating calipers. This is done so the calipers can squeeze the pads evenly from both sides. But this requires changing the caliper mounts and carefully aligning the calipers to the rotors when they are installed so the pads wear evenly. If a fixed caliper is not perfectly parallel to its rotor, the front and rear edges of the pads will not wear evenly.
There are several reasons why most aftermarket performance brake kits use multi-piston calipers instead of single-piston calipers. One is to multiply brake force. The amount of clamping force the caliper applies to squeeze the pads against the rotor depends on the surface area of the caliper piston and the amount of force generated by the master cylinder. If hydraulic pressure from the master cylinder remains the same as before, then increasing the surface area of the piston by using more than one piston multiplies braking force.
The amount of clamping force generated by a caliper can be calculated as follows: First, calculate the surface area of the caliper piston. You can do this by multiplying the diameter of the caliper piston times itself, and then multiply by 0.785 to get the total surface area. Or, use the formula 2 x 3.14 (pi) x half the diameter of the piston (the radius).
Once you have the piston area, multiply that by the line pressure generated by master cylinder needed to lock up the brakes (typically 800 to 1,400 psi, depending on the weight of the vehicle, the brake system and tire traction).
Let’s say the stock brake system has single-piston calipers with 2-inch pistons, and the line pressure from the master cylinder is 800 psi. In this case, each caliper will generate 2,198 lbs. of clamping force at the rotors.
If you replace the stock single-piston calipers with dual-piston calipers, the pistons are smaller (1-1/2 inches), but there are now two pistons instead of one. So the clamping force is now the surface area of each piston times two, times the line pressure. Do the math and you’ll see that a dual-piston caliper with smaller pistons actually generates more clamping pressure at the rotor than a single-piston caliper with a much larger piston: 2,471 lbs. versus 2,198 lbs.
If you upgrade the brakes even more and install a set of four-piston calipers, the clamping force doubles again (four pistons now vs. two). The four-piston caliper with 1-1/2 inch pistons now has a total piston surface area of 7.06 square inches and generates a hefty 4,942 lbs. of clamping force with the same line pressure. That’s why race cars and true performance cars have multi-piston calipers.
Another reason for using multi-piston calipers is to reduce pad flex for better clamping effectiveness and braking friction. If a caliper has a single, large piston and a relatively short pad, pad flex is usually not an issue. But if a caliper has longer pads (to increase the friction surface area), applying pressure only in the middle of the pad with a single piston may cause the ends of the pads to bow up slightly, with the most force being applied in the middle. So to ensure the full length of the pad contacts the rotor, two or more pistons are used to more evenly distribute the clamping force along the entire length of the pad.
To even out clamping force, some multi-piston performance calipers use different-sized pistons, typically smaller diameter pistons on the leading edge of the caliper and larger pistons behind it.
Source:
Performance Brake Upgrades