x-drilled Vs. vented...or both???

[Eurolook71]

I'm working out ideas for my future eurolooker, and have been thinkin about brakes. Tell me, who doesnt like the look of x-drilled rotors(uhhh no one), but whats the real benefits vursus vented rotors. I know most hi-perf rotors, (ex. posche, duh) but lots of companies offer either or. I've been looking at CSPs kits, and they offer...

x-drilled, NOT vented, 4x100 (the PCD I'm wanting) for $525
vented, NOT x-drilled, same PCD, for $538
-or-
x-drilled/vented kit for $667, thats another $70 for x-drilling each rotor!!

I'm trying to budget this all out, and still get what I want, but I'm curious, what would you guys go for??

[Sandeep]

If I had to choose between solid, x drilled and vented, I would go with vented. They will cool alot better than a solid disk. The principal behind a vented disk is that as the disk rotates, air can move from the center of the disk to the outer perimeter of the disk internally. This aids in cooling dramatically over a solid disk with must radiate the head (radiation helps with the vented disk also...)

my .02c

Sandeep

[lightning bug]

I'll second that. Also... I wouldn't do with a rotor that has been drilled afterwards. Porsche rotors are cast with the holes there already. Drilling afterward may weaken it.

[kdanie]

Who doesn't like the looks of cross drilling? Me! That's becuase I don't care for the "WOW" factor if it doesn't help. Cross drilling does not cool the rotor, when it is turning almost no air can go through the holes! The holes were intended to get rid of the gasses pads emit when heated by hard braking that can actually cause the pads to be forced off the rotor. Here's the problem with holes....they are blocked on the opposite side by the other pad (on solid rotors) and the gasses really can't go anywhere! It does work on vented rotors. Slots are the way to go if done correctly so that there is always a slot under the pad with an exit for the gasses. Drilled rotors often crack between the holes in hard use, slots are less likely to fail.
ken

[Sandeep]

Ken,

I agree with the slots helping dissipate the gasses during hard braking...but dosn't the slotted rotor wear way brake pads quicker than drilled ?

Sandeep

[Eurolook71]

Cool. So in reality, drilling or slotting is pretty much pointless for a daily driver. I think I'll just go with the vented kit, and keep my drums out back, of course until I can afford some rear discs. Thanks guys.

[dgluyas]

I have got 944 discs at the rear that have been cross drilled and slotted.Some say it weakens the disc. I got mine done by a very reputable v8 racing car group and they heat treat the disc and do it properly. The disc they assured me would be fine. The gas slotting helps too in their opinion. Having driven the discs before and after the only comment I could make is that they look way cool!! I personally love the look of cross drilled slotted/ventillated discs. I have not had any problems with hard braking on this setup. Pad wear is fine.

[kdanie]

Sandeep, Slotting will not wear the pads faster it it is done corretly, if it is done with a sharp edge, yes. I saw some rotors that were cut with two eliptical cuts around the hub, looked cool and did the same as the radial cuts.
ken

[lightning bug]

BUMP!

I used to cross-drill brake rotors in the early 1970's for Ducati 750GT motorcycles (180 holes in a 3/2 repeating pattern). The reason was twofold: to lighten unsprung weight and squeegee off water in the rain. Hole diameters should be equal to or less than minimum rotor thickness for solid rotors. Pad wear did not increase noticeably, but once drilled the brakes make a "chirring" sound when applied. IMO definitely vented for front and cross-drilled for all.