Performance Friction has established itself as a top braking supplier in motorsports brakes. Its caliper technology and rotor designs have won countless numbers of races in most disciplines of road racing. This success and attention to detail is what attracted me to the PFC product in the first place.
If you’re looking to upgrade your S2000 brakes, PFC has you covered with a range of options. You can opt for a two-piece rotor upgrade for use with your stock calipers, a complete streetworthy big brake kit, or PFC can design and provide you with a turnkey motorsports-grade setup. These latter are available off the shelf for cars such as the Porsche GT3 and BMW M3, but not for the S2000. It really depends what your demands call for and what your budget will allow.
For project S2000, I wanted nothing but the best. However, the cost to have the custom kit developed by PFC was out of reach for my budget, so I scoured the Internet and found that many circle track teams are using the motorsports-grade calipers and replace them long before the caliper has reached end of life. Originally I intended to use this setup with the factory ABS, so matching piston sizes was critical, but it’s difficult to find an exact match, as caliper manufacturers only offer so many piston sizes and configurations.
One thing to consider when switching from a production tire the car was designed for, which may offer, say, 0.9 g of braking force, to a competition tire, which may offer 1.3 g of braking force, is that an increased load transfer from the rear tires to the front tires will be experienced in braking warranting a slight increase in front brake bias. We have compensated for this with the selected piston sizing and slightly upsized front rotor diameter. Now that project S2000 is fitted with an AP Racing pull-type pedal box, we will be able to fine-tune the balance with master cylinder sizing and balance bar position.
The ZR22 and ZR24 calipers are both monobloc construction (made from a single piece) and feature aluminum pistons with stainless steel noses and ceramic insulators. These stainless noses reduce heat transfer from the backing plate to the piston and fluid, reducing the chance of boiling brake fluid and a soft pedal. The ceramic insulators further help reduce heat transfer.
The calipers are also available with antiknock-back springs to prevent the pads from being pushed back as a result of hub deflection when cornering or impacting curbing. Knock-back creates a long pedal the first time you go to stop after a corner/curb sequence; limiting this effect increases driver confidence and can eliminate the need to “tap up” between corners.
As our calipers were used, we disassembled, installed new seals, lubricated everything with PBR rubber grease, and installed the antiknock-back springs. Also, the leading/trailing piston orientation was incorrect on the front calipers for a rear-mounted caliper orientation, so the bleed fittings and crossover tubes were removed and flipped from top to bottom.
Next up was rotor selection. The ZR22s are designed for a 323mm rotor and the ZR24s for a 284mm. PFC has the best rotor drive on the market, so sticking with PFC rotors was an easy choice. The Direct Drive technology uses a steel drive dog that bolts to the rotor hat and sets the right amount of axial float to allow for thermal expansion, reduced knock-back, and minimized running drag. The best part of the Direct Drive is it greatly increases the life of the rotor hat compared with any other drive system on the market, all while simplifying rotor hat manufacturing.
Next comes the tricky part: designing and manufacturing the rotor hats and brackets. As an experienced race engineer, this is within my skill set and I was comfortable carrying out the task. However, if it’s not something you are experienced with, keep in mind we’re talking about your brakes here. Your best bet may be to contact PFC and have the company build the necessary hats and brackets to make your system safe and complete.
Once the brackets and hats came back from machining, a quick test fit revealed everything was to spec and fit like a glove. While it would be possible to use everything in bare aluminum, anodizing provides scratch resistance, corrosion resistance, and an excellent appearance. Consequently, I had West-Tech Finishing Inc. apply a black-anodized finish to all the brackets and rotor hats. The parts turned out great and look fantastic.
The final piece of the puzzle was the brake flex lines. The PFC calipers use the same M10x1.00 thread as the OEM calipers, so using off-the-shelf brake lines was not an issue. Goodridge makes an excellent brake line that meets DOT requirements and features an extra coating around the stainless braid for further wear/abrasion protection. Goodridge carries out the necessary testing to ensure its hoses will not fail when used properly, so don’t let your calipers dangle off your lines when changing pads and you’ll be good to go. Goodridge’s hose kit features everything needed for installation and allowed for our custom brake kit to bolt on with ease.
With everything in place, our brake setup is ready to be bedded in and tested out. With the adjustable balance bar, we will be able to fine-tune the setup and get the most from our seriously capable race brake setup.