WhiteSSP

I was doing some research at work today, and I found out that c5 corvettes, while having nearly an inch larger rotor than 98+ F body's, the pad area on them is nearly the same, being only .04 inches wider and .06 inches taller than an F body front pad. Here's some of the specs I found out:

93-97 Formula/Trans Am
5.81" x 2.66" (inner)
8.37" x 2.61" (outer)

98-02 Formula/Trans Am
7.19" x 2.42"

97-04 Corvette
7.23" x 2.48"

And just for ***** and giggles:

Ferrari F40/F50
5.18" x 2.64"

Now, I do realize that pad shape also plays a large role, however, all of the Fbody/GM pads had nearly the same shape (the LS1 F body and the c5 had EXACTLY the same shape). The F40/F50 pad was suprising though, as it is nearly an inch shorter lengthwise than the Vette pad, but i'm highly doubting that the Vette can stop anywhere near as good as the Supercars (The Ferrari's pad was nearly square in shape however, unlike the elongated arc-shape of the Vette/F body pad).

So basically, how much does the pad size affect stopping power/distance?

mitchntx

iTrader: (14)

Anytime you increase swept area, either by increased pad siz, increased rotor size or a combination thereof, you will see an increase in braking performance.

Your research didn't factor in each car's rotor size nor the pad compound.

That is good digging, though ....

trackbird

iTrader: (4)

Actually, piston area is critical. The pad can be huge, but if it has a single, tiny little piston on it (1/4 square inch?), it is not going to do much. The "clamp load" on the pad (and therefore the rotor) is dependent on the pressure in the brake system and the area of the pistons in the caliper. If you have a piston that is 1 square inch in area and have 1,000 psi, you'd have a 1,000 lb force on the brake pad. Now, add a second piston for a total of 2 square inches. Keep your 1,000 psi hydraulic pressure. 1,000 lbs per square inch, times 2 inches (2 square inches) will equal 2,000 lbs. The Corvette uses a slightly smaller piston in its front calipers to help offset the extra brake torque provided by the larger rotor. So, adding the corvette calipers to an F-body is really not an upgrade, you will lose brake "force" (clamp load) and shift the bias towards the rear of the car (LS1's already have issues with this). But, if you keep the caliper the same and increase the rotor diameter, you'll add brake force to that end of the car (the larger rotor can apply more torque on the lug studs (for ease of explanation) to slow the wheel. It's like getting a longer wrench to break a bolt loose. Make sense? So, when they added 1" of rotor diameter in the Corvette, they removed some piston area to keep the total force (at the wheel) in line with the requirements of the vehicle.

I hope you followed my ramblings.

The small, single piston I mentioned at first (1/4 square inch) would only produce 250 lbs of clamp load for a 1,000 psi pressure. See the relationship?

DONAIMIAN

iTrader: (18)

So lets say the C5 upgrade was done on an F-body. Would be it better to retain the F-body caliper while using the C5 rotor, rather than the C5 rotor and caliper. Asside from the C5 caliper being stronger.

trackbird

iTrader: (4)

Probably not. GM reduced the piston area to help keep the brakes from being "too much" when coupled with the larger rotor. It's a balancing act. I'd use the 'Vette parts as a set.

TooSlow02

Having a larger swept area or "firepath" gives the rotor extra thermal capacity, but doesn't improve the car's brake torque. Having extra thermal capacity helps on vehicles that are heavy or have inadequate rotor cooling, since the rotor is able to absorb more heat. It doesn't make you stop shorter per se, it helps keep the brakes from heat fading as quickly. If the rotor has adequate cooling or the car is relatively light, then a large swept area isn't needed. This is why aftermarket brake systems like those from Brembo, Baer, Wilwood, and StopTech have a smaller swept area and shorter pad height than some of the OEM brake systems they replace. The rotors are designed to cool quickly, negating the need for more thermal capacity, so the rotor can be made with a smaller face to reduce weight. As Trackbird said, piston area is critical to brake torque. Pad compound and rotor diameter are big factors as well.