Project EP3 Civic Si, Improving the Brakes with Fastbrakes, Stoptech and Willwood
In the last edition of Project EP3 Civic Si, we explained how we went about converting our car from 4 lug to 5 lug hubs. We did this for two reasons: one to take advantage of the larger selection of 4×114.3 bolt circle wheels available on the market and the other to take advantage of the larger RSX Type-S wheel bearings and axles to stiffen up the bearing system in anticipation of performance fixed caliper brakes and more power from a possible engine swap.
Now that we have the right underpinnings, it is time to go ahead and do the brakes!
The Dynapro also is available with small pistons and piston area, so our brake proportioning would be very close to the factory. The piston sizes are 1.62″, 1.12″ and 1.12″ for an overall area of 8.08 square inches. The stock front brakes have a piston area of about 7 square inches, so there is a little more hydraulic gain in the caliper than stock.
The increased hydraulic gain makes for higher pad clamping force and the stiff caliper construction gives a firmer pedal feel. Longer life and more fade resistance is obtained by the greatly increased pad area and the increased mechanical efficiency of having a much larger rotor also improves braking power. This gives the brakes a little more front bias but not so much that the proportioning in that out of line with stock, which will helps keep the ABS system happy.
The hats are machined from 6061 T6 aluminum and are hard anodized for corrosion resistance. The lighter weight is due to the alloy hat taking the place of a standard discs iron center. Having significantly lighter rotors gives better braking and acceleration due to their lower inertia. The light weight also means less unsprung weight, which improves both ride quality and handling as well because the suspension will be more responsive to bumps.