MXA TEAM TESTED: QTM-BREMBO OVERSIZE 270mm ROTOR:
WHAT IS IT? An oversize, full-floating, 270mm QTM/Brembo rotor with a billet bracket and slider pin.
WHAT’S IT COST? $299.00.
CONTACT? www.qtmi.com or (714) 575-5000.
QTM did not reinvent the wheel with their 270mm oversize front rotor kit, but they have added an incredible amount of quality control to the process. An oversize front rotor is the quickest and easiest way to get works-style braking?thanks to the advantages of physics, leverage and swept pad area.
WHAT STANDS OUT? Here’s a list of things that stand out with QTM’s oversize rotor kit.
(1) Tech. Common sense might lead one to believe that oversize rotors stop because they have more swept brake pad area per wheel rotation. This is true, but it’s not the whole story. Although surface area plays a part in the overall stopping picture, the main component in oversize braking systems is leverage. The larger the rotor the farther the caliper is away from the center of the hub and the more leverage there is on the spinning wheel. The bigger the better when it comes to leverage, but there is an upper limit in terms of strength, vulnerability and warpage. QTM’s 270mm full-floating rotor uses a specially prepped, high-friction rotor mated to a CNC-machined, hard-anodized, 6061 billet bracket (with caliper slider pin included).
(2) Installation. The QTM rotor installs directly to the stock mounts, using the stock bolts and nuts. Before installing the new rotor, take some contact cleaner and wipe any contaminants off the new rotor (to avoid contaminating your brake pads). When mounting the rotor, use a medium-duty Loc-Tite on the rotor bolts. Some rotors are secured with nylon lock nuts?they don’t need thread lock compound.
(3) Performance. The QTM brake delivered a very solid and powerful feel. When coming into turns hot, the ability to modulate braking was good, but going from 240 or 250mm to 270mm does increase the pucker power enough to require more concentration. Where the QTM shined was in overall feel. It upped the braking power significantly and did it across the complete friction curve?-which means that there was more power at low speeds and a lot more power at high speeds.
(4) Pads. We ran the stock OEM brake pads with the QTM/Brembo rotor. They worked great and were a known quantity. Once you become more comfortable with the increased braking power, you might want to switch to higher friction aftermarket brake pads, but we doubt it.
WHAT’S THE SQUAWK? No problems, but break-in is essential. As a rule, MXA takes the new rotor and pads out to an open space and slams the brake on as hard as possible about ten times. After each stop we wait about 30 seconds for the brakes to cool. Do not break-in the brakes by dragging them.
This is a no-brainer. The keys to better stopping are new brake pads, high-quality materials and the biggest rotor that you can justify. In our case, the QTM/Brembo 270 kit meets our criteria.