ThunderDent

Thought I'd take a quick survey to see opinions on what the most popular esthetic favorite look was for slotted rotors.

I am getting them installed Friday.

From what I read, if the internal fins are directional, then you don't have a choice, but if the internal fins are parallel straight up the walls of the rotor (pretty sure this is the case with the Adams rotors), you can pick your direction.

"For slotted rotors with straight internal cooling vanes, the direction of the slots is totally up to you and what you think looks best. In this case, there is no wrong answer."

http://zeckhausen.com/how_to_properl...all_rotors.htm


So if I can get this poll function to work... pick your favorite and I'll see how it stacks up against my own thoughts....

Rotor slots facing toward front

Rotor slots whisping toward rear

ThunderDent

Even though I selected poll option with 2 choices it didn't let me post it that way, so just leave your choice in the note.

I'm pretty sure which way I'm going with already, just wanted to see others ideas

Parsec

Pointing towards the front looks more aggressive (top left), but Pointing towards the rear looks more aerodynamic (top right). Personally I like it pointing towards the front (top left rotor mounted on driver's side front).

ThunderDent

That's my choice as well. Pointing toward the front looks the coolest to me.

johncaravello

I am be no means an expert but I believe the holes are for cooling and the slots are to evacuate the dust. So one would think the most efficient way to get rid of the dust would be to mount them so they look like the top right and bottom left with the slot slanting back when on bottom. I'm not sure if that is even possible at all corners. Just an opinion, I could be totally off. I'd bet a race mechanic would know.

Reisen

Nope. Both are for heat. I have also heard, however, that cross drilled / slotted rotors can also provide more initial bite, because even though they have less pad contact area, the edge of the slot or hole can "bite" into the pads. This, of course, wears pads faster.

Not sure if the second is correct, but I can say both cross drilling and slotting is done to reduce fade due to heat build-up.

ThunderDent

I've read differing opinions and claims:

Cross drilled have potential for fracture, if not cast that way, but dissipates heat the best.

Slotted gives you better stopping efficiency out of all the designs (although some state you only see it on the track vs daily driving).

Slotted will eat you brake pad lining 20% faster, but vents the brake gases better.

Dimpled dissipates gases much less than slotted, but is easier on the brake pad lining. It's more for esthetics.

Both dimpled and cross-drilled are noisy and make a popping sound (esp dimpled) when gas is trapped in the dimple.


It's hard to say what is the best. I'm sure they all have their risk/benefits.

Reisen

FWIW, I've always just gone with standard rotors on my cars. I might spend the extra money if I had a high performance coupe / sedan (something like an M3 or S4/S5), but it would be mainly for looks.

Also, I vote slots facing back.

ThunderDent

Yep, I'm going for looks more than performance. Several articles state performance is really only seen in a track situation anyway.

Parsec

I think at around 365 HP and about 395 ft-lbs torque, his Q5 is already way more powerful than an S4/S5. He needs a bit more tweaking to catch up to the M3 though