This is a topic that always seems to raise questions. You may have already heard it – GTO owners are using C5 brake pads in their GTOs. It is a simple drop in mod. From what I have found, C5 Corvettes and GTOs all have brake pads that share a common interface. Stated differently, they all use a similar backing plate, which allows them to be interchangeable. This should also be the case with the new C6s. The amount friction material on GTO and C5 pads is significantly different, however. The pressure the caliper applies does not change, but the area to which it is applied does. The larger and wider area of the C5 pads results in better performance and less fade, especially for 04 GTOs. The C5 pads wider sweep area means you need to install them on a fairly new rotors or have your rotors turned since the increased pad area of the new pad will be touching areas not previously worn down by the GTO’s OEM pads. I did have to remove the C5 pad wear indicator to prevent interference with the GTO’s caliper bracket. The other advantage of C5 pads is that there are more choices, better availability, and you will pay a lower price. For reference, the GM part no. is 88909667 - Description: 97 to 04 C5 and Z06 Corvettes Front Ceramic Pad Kit.
The compound the pads are made of is also important. If you will be performing multiple high-speed brake applications, it’s critical. I’m still learning in this area and believe high quality pads that can operate over a ride range of temperatures are a must. They need to work well when they are cold or during normal street use but also have to be able to stand up to the heat generated from high-speed haul downs. Dedicated racing requires pad compounds that can sustain high temperature operations. Racing pads actually have to be heated to their higher operating temperature before they work effectively and would be dangerous to have installed for everyday street use. Using normal street pads in racing conditions or at the triple digit speeds the GTO is capable of can result in pad failure and or pad compound forming deposits on the rotor surface giving you a “wrapping” effect. This will cause your steering wheel to shake when the brakes are applied. If this persists, you will need to turn or replace your rotors. I currently am using Raybestos QS Ceramics, Part# PGD731QS. They are quiet, low dust, and have operated successfully at 100 mph on the track during some cool weather but I’m not sure how effective they would be if the heat generation was greater. There are a lot of performance pads out there. Make sure you do your research including using the search function on the forum.
After installing C5 brake pads and flushing my brake lines with Valvoline SynPower in my 04 GTO, I had noticeably more brake authority and the anti-lock braking system would frequently engage on dry pavement, i.e., the OEM BFG KDWS tires were now the limiting factor. I found the 2004 brake set-up adequate for normal street driving situations, but not for triple digits haul-downs or track days. I also was not satisfied with the firmness of the brake pedal. With hard brake pressure, the pedal would continue to move toward the floor (remedy for this is in the last section). The 05 and later GTO brake systems are much more robust, stand-up to the occasional track day, and have a stiffer pedal feel.
