if the reason for cross drilled rottors is to reduce heat... and by using them backwards, they accually build up heat, thus getting hotter...

so while one side is accually cooling down, the other side is heating up...

the brakes would be less effective wouldnt they? because they are hotter...

soo... because brakes on one side are being less effective, thus giving a loss of control...

AIR COOLING
Most of the enormous amounts of heat generated during deceleration must be dissipated into the free air stream.

Most high performance (and/or heavy) cars today use some variation of the "ventilated" brake disc in which air entering the center or "eye" of the rotor is forced through the interior of the rotor by the pumping action of the rotating assembly. The most efficient practical way yet devised to accomplish this is through the use of the "curved vane" ventilated brake rotor originally designed for the LeMans winning Ford GT 40s in 1966. In this design the interior vanes are curved to form an efficient pump impeller. They also stabilize the rotor from distortion and serve as very effective barriers to stop the propagation of cracks due to thermal stress. In laboratory testing STOPTECH's innovative design developments in the 48 vane rotors have increased air flow through the rotor by an astounding 61% over some OEM rotors and from 10-15% over racing rotors of the same size. This results in a cost effective but very stable direct replacement rotor that runs typically 15% cooler than stock and 7% cooler than racing designs.

Which is better, slotted or drilled rotors?
StopTech provides rotors slotted, drilled or plain. For most performance applications slotted is the preferred choice. Slotting helps wipe away debris from between the pad and rotor as well as increasing the "bite" characteristics of the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage. Many customers prefer the look of a drilled rotor and for street and occasional light duty track use they will work fine. For more severe applications, we recommend slotted rotors.
How do I tell what direction the rotors go on the car?



(Driver's perspective looking forward)

The StopTech AeroRotors® are directional. If they are not installed on the proper side of the vehicle, airflow will be restricted and cooling will be severely diminished. The vanes on a rotor act like a centrifugal air fan, drawing air from the inside of the rotor and flowing it to the outside. The vanes of a directional rotor should arch back like arms on a pinwheel. On the top side of the rotor, the vanes should curve toward the back of the car.


(Driver's perspective looking forward)

The slots on StopTech AeroRotors are cut in the OPPOSITE direction of the vanes. The pattern on a drilled AeroRotor also has the same appearance. The direction of the slots or hole pattern should not be used to determine what side of the vehicle to place a rotor. Different manufacturers may have different strategies for slot and hole patterns.

The only correct way to determine what side a directional rotor goes on is the internal vane direction.