Well? :smile:

 

THey channel heat and provide more stopping power... but what to I know?

 

Which mean they heat up faster bringing the disc to operational temp quicker improving braking. Also they have better Bling Bling value.

 

The slots do not chanel heat, but provide a place for the gas that forms between the Brake Pad and the Rotor to escape, the same thing goes for Drilled rotors. This allows better contact between the Brake Pad and the Rotor, which decreases stopping distance.

 

from a purely structural standpoint, I would think that the removal of metal, either by drilling or slotting would have the undesirable effect of weakening the rotor,making it more prone to warpage and diminishing contact area.There is an advantage in cooling the rotor down faster ,and certainly heat is the enemy of good braking.I'm not sure if one cancels out the other, however.For standard road only use, I think it's more the *bling*bling* factor.

 

I like them. I have never had any problem stopping and they feel good, smooth, no fade I can feel.

Got the Power Slots (stage one) from Randy Webb. He is a sponsor on this site.

Earl

 

Just thought you wouldl ike to see a nice close up of the rotors that we have.

 

This picture looks like the slot is more like a 'trough'...wouldnt the gas/dust from the pads escape better if the slot extended all the way to the edge? I've seen other rotors that are designed that way.

 

Just curious Pilo, how many track days have you done with these brakes sofar and how are they holding up?
I installed a set of the Racingbrake rotors. They seem to work well, and I'll be doing a track day next month.
THoughts?

 

That is a common misconception. The Slots are there to "scrape" the gas away from the pad, and very little actually escapes from the edges, when the slot clears the brake pad, the gas is then vented away from the rotor. One reason not to slot all the way to the edge is to aid in preventing stress cracks at the edge of the rotor. I have seen rotors where this has caused structual failure of the rotor.

Regarding the longevity of these rotors, I have done several track and autocross days with this rotor. During one track day, I actually ran out of pad, and had metal to metal contact on the rotor with out damage. I have been very happy with these rotors.

 

Slots are meant to wipe the pad of particiles. Slots extending to the edge would be a good point for stress lines to develope as the metal mass expands and cools.
I ran a set of drilled rotors on my last car mostly street use and never had a problem. To be honest it was for the bling bling look. When it comes time to replace the OEM rotors they will be sloted as shown with no holes.

 

Todd at TCE is a guru on this stuff. From chatting with him, and reading his comentary in that forum, they have the benefit of allowing rotor gas temps to escape, as well being a self-cleaning feature. I suppose for some, bling is a consideration...

And since there is always a balance involved, there are negatives: less surface/contact area (as with drilled), slightly less mass (to some degree more weight can be a positive thing actually), and they are more expensive.

He turned me onto to just getting slotted pads (with the WW Race Kit) .

 

Pilo i did mean to say they Channel heat. But yes they do remove the gas which allows for better contact. Which inturn causes more friction which generates more heat. Is this not true.

 

This is true, but this is a good thing. This means that you are stopping faster. Unfortinatly, the effect of stopping generates heat.

 

Ask yourself why you need to replace your stock rotors.

If you are doing street driving only and only a little autocross or track then the stock rotors will work, especially if you have upgraded the brake pads and or brake fluid to handle heat better.

If you are serious about track and autocross then first check to see that the class you are driving in for autocross will allow for changing your rotors to slotted ones and not bump you to a more competitive class.

Most times a good quality basic stock sized rotor will work. It may not look the nicest but it will function fine. If you press the limits of it's design with hard braking on the track then having slotted rotors might help a little. For autocross you don't need slotted rotors.

If you want the looks of slotted rotors then you'll have to pay a bit more for that look. You do loose some rotor surface area but you do allow for removing some of the boundary gas that forms.

Drilled rotors can be used for street use without too much trouble but on the track with the high heat, a very common eventual problem is cracking at the holes. I've seen it.

If you really want to improve braking then a big brake kit with larger calipers and larger rotor diameter for front and maybe rear brakes would be significantly better.

 

Based upon my experience, I totally second Minihune's very thoughtful and knowledgeable response. I have gone through 2 sets of slotted rotors and have never noticed any improved braking response from slotted rotors. I'm back to using OEM rotors because they're just so much cheaper and they work fine (yes, even at Driver Education events on tracks). For street use only, you would never notice the difference -- the main reason to get them is for appearance. Other than a big brake kit, the best way to improve braking for high performance events is to change to a high end brake fluid and get better brake pads. My .02.

 

I'm with Galaxie500, I'm going back to OEM or Brembo OEM sized rotors, no slots, no holes. I've driven with them all and can't see the added benefit equaling the added cost. I did a lot of track days (18) last year, and will do so again this year. Rotors and pads need replacing frequently in those situations, no matter what. Why spend more than you have to?

 

I bought the drilled/slotted RacingBrake kit from Pilo because my stock pads/rotors were toast and they were very resonable in price for everything (~$400). Hawk HPS pads included.

That said, I will do a track HPDE maybe 1-2 times a year, so I'll have to see how they do, but after contacting RacingBrake about concerns with the drilling and cracking, I'm convinced they will survive a trackday and still be ok. They appear to be very good quality rotors.

I'll be able to report after my trackday Feb 7th.

 

I have sat down with the guys at RacingBrake many times, as they are local to me. Just talking to them has convinced me only to sell their brand. They really know their brakes, and have worked with me to make sure that every thing performs as they expect. We have been very happy with the results that we have been seeing with the rotors on my car.

 

find a pad that has a slot cut into the friction material, and you get the same degassing effect. Any time that you cut a material, you interrupt the grain structure, this weakens it. The cut leaves a sharp corner that is an excellent place for a stress riser, and depending on the microstructure of the material itself (any material with any bainite steel structure has built in stress risers, due to the structure itself). So it really comes cown to the quality of the castings, and any heat-treat processes that reduce internal stress before/after machining.

 

Most of today's pads dont require the degassing that pads of years gone by required. Slots offer a new biting edge into the pad, and may increase the amount of dust.

The width of said slots determine how noisy the rotor will be.
Wider gap, more helicopter like noise. I do agree that treating the face of a rotor does remove material, and inturn decreases structural ridigity.

A sold face rotor is the very best choice for "motorsports" involvement. It will function as the most ridgid heat sink.

If you wish to concider a treatment from "motorsports" Cryogentic treatments have been very sucessful. (its the same advantage as T6, but done in cold, not warm.) More to come in the near future!

Alex