slotted vs cross drilled rotors

[blueillusion97]

slotted vs cross drilled rotors. Which would be better for street and some track/autocross? Also can either be resufaced like regular flat rotors?

[Gary in BR]

For the past 2 years i have used the cross drilled. From my understanding either will work on the track very well, the cross drilled would work better in wet conditions.

[racer_d]

The drawback to cross drilled is there tendancy to develop hairline cracks. Rule of thumb is once the cracks link one hole to another, the rotor is done. Slotted rotors don't behave this way and would likely be a better choice for your needs.

People don't re-surface rotors much anymore.

Also consider that a change of brake pad compound and brake fluid bleeding can have a greater impact on braking than simply changing the rotor.

[insite]

Originally Posted by racer_d

The drawback to cross drilled is there tendancy to develop hairline cracks. Rule of thumb is once the cracks link one hole to another, the rotor is done. Slotted rotors don't behave this way and would likely be a better choice for your needs.

People don't re-surface rotors much anymore.

Also consider that a change of brake pad compound and brake fluid bleeding can have a greater impact on braking than simply changing the rotor.

agreed. there's very little differenc in performance between flat, slotted or drilled rotors. there is, however, a HUGE difference in performance between pad compounds. if you REALLY want to stop well, realize that the weak link in your braking system is usually your tires, so upgrade those.

if you go to the track a lot, consider getting your rotors cryo treated. it's about $30 per rotor and will keep them from warping. they will also last much longer.

[drburton]

I don't really know much about this, but for heavy use on the track isn't there an advantage to the drilled b/c of airflow and cooling.

[insite]

Originally Posted by drburton

I don't really know much about this, but for heavy use on the track isn't there an advantage to the drilled b/c of airflow and cooling.

supposedly. i don't think that the airflow issue matters much as essentially all high performance rotors are vented anyway; this provides the primary means of convection cooling. i DO think that drilled or slotted rotors help w/ green fade or with transfer buildup by giving escaped gasses, brake dust, etc a place to go rather than between the rotor and pad.

i don't think you can install a drilled rotor on a car and really tell the difference between a solid one. if it makes a difference, it's secondary, and it carries an added risk of cracks and an added disadvantage of reducing swept area. i DO know that plenty of race teams opt for solid rotors.