That and the calipers are from their racing line and racer list is 580 each.

 

Nice, You could install 2 on every wheel.

 

FI pushes you out of bounds because in theory (and practice) you have to burn off more speed in every brake zone. If you're going 5% faster at a corner then you are going to use that much more brake to slow you to your corner entry speed which isn't going to change.

Multi-piston callipers are designed to spread the pressure to the pad more evenly. They don't change the total amount of pressure being applied.

I think what triv is saying is that the wilwood rotors have less total mass thus weight but the mass is taken from the hat area and not the contact surface. The hat area doesn't participate in energy absorption and dissipation.

 

Yes you have to burn off more speed, the question is whether or not that speed is more than stock can handle. Out of the 3 of us, I'm the one running FI and for the most part they seem to be working just fine.

And the hat portion would be a part of the mass too. No reason to assume heat doesn't get stored there too.

-Ry

 

Actually there is reason to believe the hat doesn't participate significantly in heat absorption, your aluminum wheels melt at 660C which is close to the normal surface temperature of the rotors under braking. The hats are in direct contact with both the wheels and the spindle and bearings. You can argue successfully that having a significant heat transfer from the rotor contact surface to the hat is not a good thing.

You want the heat absorbed by the vented rotor surface and then quickly dissipated to the air via the vents. You certainly don't want it stored in the hat/wheel/knuckle.

 

You would have to transfer a lot of heat to start a melt down on a wheel. That aluminum wheel can dissipate an enormous amount of heat from the hat, if it ever got there. Prior to that happening pretty much everything else around the rotor would be toast.

 

On a side note:
could i get a link to a place to purchase the willwood 4p setup? The price seamed right and lighter calipers are awesome. Willwood's website doesn't list any applications for our car.

 

Wilwood themselves doesn't make the kit for our car. It's kind of a custom solution. PM "Partshelper" (Spugen)

 

I have the Wilwood 4 piston kit, braking is about the same as stock, benifit is the weight loss, the looks and the pad selection.

 

My point exactly. There isn't a great deal of relative heat transfer from the friction surface to the hat. Most of the heat in the rotors says in the friction area. I'm not saying there is no transfer, I'm just saying there isn't enough to justify the added mass of a solid cast iron rotor hat. A steel or steel alloy hat and iron friction surface does just as good a job of heat management but at a lower weight. Not all mass is created equal. If you have a pyrometer with a brake probe you'll see this quite clearly.