Brakes, Cross Drilled and Slotted?

[seanm173]

I am looking for a new set of rotors for the front of my GS. I was wondering if people who have aftermarket rotors could tell me thier opinion of the ones they got. I hear powerslot and KVR rotors are good, but I also found these on E-Bay do you think they are any good? Has anyone used these? <p>heres the Ebay link: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=33564&item=2426974452

[Custommx3]

Please do a little searching. This has been posted many times.
And I had powerslot x-drilled, had a hell of a time getting them turned. But I liked them.

[seanm173]

i've done searches, my biggest question was about the Ebay rotors. I haven't seen these before or heard anything about them.

[Custommx3]

http://www.mx-3.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=001098<p>http://www.mx-3.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=1&t=002495

[seanm173]

Thanks for your help Custommx3. I however am still interested in hearing if anyone has used these rotors, and what they think of them.

[C-MX-DA3]

posted by CustomMx3"And I had powerslot x-drilled, had a hell of a time getting them turned"
yo barry! what do you mean by getting them turned? is it true that slotted or drilled rotors sometimes cause vibration when braking?

[JasonH]

In general, the claims made in that auction (and by most other sellers of cross drilled and/or slotted rotors) are false.<p>Decrease your braking distance
They simply won't do that. It's impossible. Larger brake pad to rotor contact surface will decrease braking distsnces. When you drill holes or make slots in a rotor it decreases surface area. It's simple physics.<p>Increase the life of your rotors and brake pads
No again. Brake pads last longer on smooth surfaces. Slots are actually made to cut some brake pad off to prevent glazing. Drilled holes in your rotor, no matter how expertly drilled, will introduce stresses not found in solid rotors. Solid rotors will last longer.

Dissipate heat, debris, and water away from your vehicle
Although the holes slightly increase the surface area exposed to air, and therefore will make the brake rotors cool off faster, this benefit is offset by the material that is lost when the holes are drilled. This material would normally be used to absorb heat while braking. So while they can dissipate faster, they cannot absorb as much heat. This negates most of the benefit. Yes, if you drive through a lot of water, they will get rid of it faster than regular rotors. I don't know what kind of debris they're talking about, but if you have debris in your brakes you probably have bigger problems.<p>Perform up to your expectations under a variety of conditions
I expect them to perform worse than good non-drilled or slotted discs. They will perform up to my expectations. If you expect them to be better, they will not.<p>If you're buying them to look cool and don't care about decreasing performance to do so, by all means, buy them.

[lazzyie]

^^^^ I applaud that post

[seanm173]

If having cross drilled or slotted rotors is only an apperance thing. Then why do race cars have them where the only thing that matters is performance?

[seanm173]

I retract my previous statment. After doing a little research I found this on the Wilwood Faq section of thier website.<p>Q: Why are some rotors drilled or slotted?
A: Rotors are drilled to reduce rotating weight, an issue near and dear to racers searching for ways to minimize unsprung weight. Drilling diminishes a rotor's durability and cooling capacity. <p>Slots or grooves in rotor faces are partly a carryover from the days of asbestos pads. Asbestos and other organic pads were prone to "glazing" and the slots tended to help "scrape or de-glaze" them. Drilling and slotting rotors has become popular in street applications for their pure aesthetic value. Wilwood has a large selection of drilled and slotted rotors for a wide range of applications <p>So, I have to say well said Jason, thanks for your help.

[JasonH]

Thanks, guys. Nice to see I'm not just boring people to death .

[playaa]

Wow, JasonH just educated me in that post.. ::Applaud::

[MazdaManiacMx3]

Do they make oversized rotors for our cars ?
Also what would you have to change if you use oversize rotors

[JasonH]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by MazdamaniacMx3:
Do they make oversized rotors for our cars ?
Also what would you have to change if you use oversize rotors<hr></blockquote>
There are two ways to do oversize rotors:<p>1)The rotors can be larger but you keep your stock calipers. There is a benefit to this as you have more swept area on the rotor and also a larger rotor mass, but you're keeping the stock caliper and same size pads. You would have to swap the rotor as well as obtain a spacer (the red things below) to move the caliper farther away from the center of the rotor. It looks something like this:<p><p>2)The rotors and calipers can both be larger. This will improve braking more than a "rotor only" swap as you will have substantially more swept area and larger pads, as well as the larger mass of rotor to absorb more heat. The four-piston calipers should also provide more clamping force and better heat transfer properties (to help keep your brake fluid from boiling.) It looks like this:<p><p>These images are Protege kits from Precision Brakes. I believe they will fit the MX-3, but I'm not sure.<p>I would recommend solid vented rotors over the flashy drilled and slotted ones, of course.<p>[ August 16, 2003: Message edited by: JasonH ]</p>

[fabius]

Here here nice to see some serious chat about this, yes X-drilled and slotted are only for show on road cars but what nobody's mentioned in CAST IRON DISCS. Yes they're extremely hard to get for cars but having been riding bikes that have had these fitted try and get them, if you cant, get em made. Not sure why but on bikes there's an average of 40% less braking distance less and less wear but be warned they have to be warmed up first. If I find a source or an engineering firm to do it I'll post they're details