My rath is directed more at Wilwood than PST but they aren't doing themselves or their customers any favors selling brake kits more suited to a 3000 lb race car than a C-Body that can be upwards of or over 5000 lbs.
A caliper and bracket kit that used stock 11.75x1.25 rotors would have been a much better fit for that particular niche market IMHO.
Kevin
Here's my .02 (will probably be $1.50 before I'm finished):
I agree it would be obviously better if the rotor was thicker, but it was probably based on other 11" kits, and the ~.75" thickness is a common 'lightweight' rotor size. From a mfg perspective it makes sense, change the brackets and hubs/bearings and you have a whole new car application. Regardless of any claims of increased braking capacity in a brake system, the rotor
must be able to dissipate the heat without warpage, and unless special rotor vent/vane designs are used to 'pump' air more efficiently, the thinner/lower mass rotor would be more likely to warp under the same heat load. HOWEVER - this rotor is a bolt-on, and looks like it could allow some expansion capability at the mounting bolts, possibly reducing the likelihood of warping. Is it sufficient??? Who knows. How robust is this rotor in C-body applications??? Who knows.
Is this kit effective enough for a C-body? Perhaps. This is a comparable rotor size to OEM Hemi B/E body, which can tip scales at over 4000, and some lighter Slab C's are right there. So we cannot simply say a brake is suitable or not simply by chassis designation -- more consideration should be done. Probably good enough for a SB Slab without a lot of options, probably not enough for a Fusey sedan with lotsa power options. Driving habits will be a major factor too.
Second even though the rotor is a .25" smaller Wilwood has made that up with the clamping force of a four piston caliper compared to a single piston caliper. The four piston set up has more piston contact surface area.
The rotor is .75" smaller in dia, and that .75" is a bigger difference going from 11.75 to 11 than it would be going from, say 13.75 to 13". And I'm sorry, the comment that the caliper is larger and therefore compensates for the smaller rotor dia vs OEM is a marketing statement. We follow the rules of physics on this site, and force = pressure x area. If you double the piston's area, the force on that piston cuts in half. Make your pad twice as big as stock -- same thing happens (although your pads might last longer as the heat per area is cut in half). The picture above does not show any MC or booster (which is the pump for the whole system) so we must presume its output is unchanged. Multi-piston calipers *can* provide advantages (more even pad application, larger pad size, less heat and gasification of the friction material - although our smaller OEM pad could be less likely to deflect). However I believe those design features do not necessarily translate into better braking performance, they are more for durability.
The ways to increase braking performance are to add more leverage on the pedal (more input), increase a booster's output (more input to the MC), increase rotor diameter (more braking torque), or increase friction coefficient of the pad/shoe material (more friction for same pad pressure).
Now I don't want to knock this kit, I agree it has a major convenience to it - no sourcing spindles, nor dealing with old balljoints that might spin in their sockets when you try to remove/install the nuts. If your susp is serviceable, this makes a disc swap much faster with less likelihood of a snowball effect. But for some folks wanting to keep 14" wheels/hubcaps, there's the ECI kit which fits behind disc-compatible 14" wheels - with the same rotor diameter (and with the same marketing about bigger-piston calipers). So you can keep your stock 14" hubcaps with ECI. Both of these 11" kits seem like they should provide better braking than the original drums -
but whether they perform as well as the factory 11.75" discs requires back-to-back testing/data, not marketing hype. Ideally we'd have 3 tests - drums (repaired/'certified' to be at 100% operation), factory OEM discs (same repair requirements) and the aftermarket kits. Haven't seen that type of info published very much, if ever.
I've simplified my comments here a bit (I've ignored the complication of brake fade, for instance) but if I've said anything incorrect or confusing I am willing to clarify and learn from any solid rebuttals.