DBA E9X 335 Slotted Rotors, 4000 Series

Improve your E9X 335's brake performance with a set of DBA 4000 Series rotors for serious street and dedicated track use.

Designed specifically for the performance street and motorsport enthusiast, DBA's 4000 Series rotors incorporate a slotted disc face called "6x6 Wiper Slot" for better pad outgassing and increase coefficient of friction. The 'micro-shaving' effect of the slots also serves to de-glaze the pads (this is why the edges of the slots on DBA Street Series rotors are not chamfered or 'radiused'). It also tends to even out the wear across the brake pad faces, increasing the effective contact area and extending rotor life. Another great feature of DBA's 6x6 Wiper Slot design is they are not machined through the disc's face, greatly reducing the chances of cracking at the edges of the slots. This is a serious concern for track use where typical inferior slotted and cross-drilled designs will crack over time, greatly reducing the life-cycle of the rotor.

In the premium 4000 Series, DBA uses a patented hi-tech disc rotor ventilation system called "Kangaroo Paw" (enlarge picture for cut away image). The design features a series of 144 diamond and tear drop shaped pillars and columns, individually spaced between the rotor faces. This system provides two key advantages. One advantage of this design is the ability to cool the rotor faster than ever before. This works on the same principal as an air-impeller, designed to extract hot air. As the disc rotor rotates, aerodynamic turbulence around the individual pillars and columns is generated, increasing the force of hot-air out from within the internal areas of the rotor. The second advantage is the increased dimensional stability across the disc rotor, directly achieved by the individually spaced pillars and columns. These advantages increase the disc rotor¡¯s efficiency by as much as 20% when compared to conventional rotor designs.

Another key feature to the 4000 Series is the thermo graphic heat paint seen on the outer lip of the rotor. This monitoring system has been developed to measure the actual bulk temperature** of the disc when operating at the most extreme condition. In order for this color change to occur, the disc rotor mass must reach the relevant bulk temperature for 10 minutes. This ensures that the color change does occur from the much higher surface temperatures which do not penetrate through the disc material and affect its mechanical properties. The ideal temperature condition for high performance brake pads and rotors is between 450C and 550C which is when the peak friction condition is achieved. This can be verified when the green paint changes to white and the orange paint has not changed or minimal change occurs on the outer edges. If your driving conditions force the orange paint to change to yellow then you should consider more a specialized high temperature pad compound, review the car setup or alter your driving style. When exposed to temperatures in excess of 630C (red paint) permanent fatigue and stress concentration is greatly accelerated which may result in premature cracking or warping of the disc rotor*.

The three paint stripes on these DBA performance rotors are;

Green 458C (856F) Changes to white
Orange 550C (1022F) Changes to yellow
Red 630C (1166F) Changes to white

Applications include all E9X 335s including the 335xi. Rotors are a direct replacement. No modification to existing brake system is required.

*DBA does not warrant disc rotors that have been subjected to motor sport use.

**Bulk Temperature is the temperature achieved through the full thickness of the material rather than surface temperatures that may be much higher but have less effect on the mechanical properties of the rotor material.

TS16949:2002 Certified. Exceeds ISO 9001 and QS 9000 quality standards.

Made in Australia