[Dave-ROR]

Originally Posted by D K

Im not sure exactly but I definitely wouldnt label those as cosmetic.

They have a different.design for rotors and that allows them to be thinner.

On the FD (same size I think) they were fantastic.

Really intrigued with this kit

They might cool a LITTLE better if you run ducts. The center mounted design is to allow for cheap hat production. The way it center mounts has to create a crapload of turbulence though..

One of the rotors primary jobs is to pull heat away from the calipers and hold it until it can be removed. Heat removal is NOT the primary job. Because of that, an INCREASE of thermal mass is always going to be required if the OEM size doesn't have enough mass (which depending on the driver/car/track, it may not - for me at Sebring for example it definitely does not). This kit doesn't increase it so to me, there is basically zero functional difference between this and stock except for what I already noted.

For the FD3S (with a different hat obviously) then this would be a larger rotor than OEM... so there's an increase in thermal mass in that case...

If they work any better on track in a car that has reached or passed the limits of the OEM rotors with good pads/fluid, great, but call me extremely skeptical.... A BBK for me will always be focused on fixing a problem. That problem will always be a need for additional thermal mass. More efficient cooling, weight savings, consumables, and a few other items are secondary and of varying importance.

Speaking of consumables, are any of the excellent pad choices available for these calipers? What's the pad shape? If not that would eliminate it even if it were the best brake system ever... but I have to assume that it's a common pad? I hope? Also the calipers are 6061-T6 alloy, from what I recall that's not the most ideal alloy for calipers.