A motorcycle weight close to 500lb with a rider yet the front rotors are often larger than the ones on a car. Pads are smaller though. Comparing that to a 3,400lb car only means the bikes brake need to work ~6 times less hard than the ones on the car... More intense ?

Plus, the cost of one bike rotors is often more than a full set of good rotor for the Z...

 

I don't think its necessarily apples to oranges. Your statement that slotted rotors produce more dust had no caveats in it...it was as general, and broad of a statement as you can get. As such, my reply, though annecdotal, was similarly broad based. My Z should have the propensity towards more brake dust by your theory, based on the fact that its got a far larger pad than my Audi, slotted rotors (vs solid on my Audi), and pads that generate a far higher coefficient of friction vs the stock pads on my Audi. Yet the brake dust produced by my Audi in a 100 miles of use is equal to what shows on my Z after roughly 400 miles. My point is that yes, of course a slotted rotor produces dust - as does a solid rotor. However I disagree that given similar pads, and similarly compounded rotors, one produces more dust vs another. You can't make that type of statement without knowing the properties of each material involved. It's the nature of two materials, especially those designed to cause friction, rather than prevent it, rubbing together.

My only bone of contention (for lack of a better phrase) is you seem to be saying is that your way is better. It works for you...cool, more power to ya. Your going a bit further than merely "this is what I run and why". You are insinuating your way is better, but its based largely on your opinion, which I don't think any data shown to date, necessarily proves. Your links and opinions have shown that yes, your way is working for you, given your set of circumstances. Others posts have shown that there are other setups that work too. Which works better? That would be quite an involved "test" so I don't think it's likely we'll ever get those results. There are different ways to skin a cat.

My ITS BMW runs slotted rotors and Hawk Blue pads - I change pads 1 x per year, and have not changed rotors in 2 years. I wonder why I get such great rotor and pad life? My guess is the car weighs the minimum amount (I have to add weight), and runs Hoosiers.

I think you are taking disagreement too similarly to personal attacks - no one is personally attacking you at all.

 

x2

I don't think that slotted is the only way to go with a rotor on a track car, obviously some track cars are using drilled and some blanks. If blanks work for you that's fine, I just don't feel a blank is superior to a slotted when it comes to the track. Some of my theories may be wrong, but I'm on this board to learn, and if I come back learning just one more thing about brakes it makes this all worth it.

 

The whole discussion is focused on the use of slotted, drilled and plain rotors.

I agree that the system has to be taken as a whole at some point. But since the current discussion is focused on the rotors themselves, there is no reason to bring different uses and application in perspective when comparing "dust production capabilities".

I would find it hard to believe that in a "dust test", if such a thing did exist, performed on one car in controlled condition with plain vs slotted rotors, the dust production would be equal... Common sense and general consensus points to that too (ie slots are better because the clean your pads). You can't accept one without the other!

Of course I think the direction I've taken is the best for me. What sort of a stupid person would I be otherwise?

Hey, anything can "work". Nobody on the street ever use their brake system at 100%.

It's my understanding that your Audi is a track car? And that you run solid rotors on that car? Interesting...

 

No one is saying they wont dust more, but you paint the picture you will be going through pads like a woman at that time of the month, which isn't true. Several people who have run and are still running slotted rotors have straight up said there is barely in difference in pad life/dusting. I had slotted rotors on my prelude back in the day and had no problems with decreased pad life. I'm putting a set on my z soon, and I will see how long they last.

 

No, my Audi is my daily driver (dd)

Again, I didn't bring the dust issue into it, you did. I simply was sharing my annecdotal experience, just as you are, between my daily driven Audi, with a complete OE setup using solid rotors and Audi's OE pad, to my often driven Z, with a big brake kit (bigger pad), using slotted rotors, and pads that are considered (by the manufacturer) to be both street friendly, and track-able (I have not tracked the car yet with these pads).

My previous setup (a different BBK) used both slotted AND drilled rotors, and I experienced no compromise in pad life (used both DS2500's and Porterfield RS4 (or R4S...I always forget the name). In fact, that first set of brakes was used (on a Z32 twin turbo), and had gone through quite a number of track days even before I got them, yet I never had a crack in any of the holes (not using any cooling ducts either), and did quite a number of track events myself.

My other car, and older Datsun (with a bunch of power) uses x drilled rotors at present, with this pretty funky pad (that is no longer made unfortunately), and while I never tracked it, it's gone 5 + years without ever cracking a rotor (the stops I do on that car tend to be from 120 + down, as it's really a top end type of setup).

 

Why do you guys not want me to say that plain rotors are better overall? They are!

Pad matching is of the outmost importance. That is what will affect the feel and performance of the brake system the most.

The discussion slid toward dust production. But please, remind me again what the advantages of running slots are? I'll be surprised if "Run the right pad" doesn't cancel the issue/performance gain we might get with the slots each time...

Evacuating gases? - What gases if the pad is designed for the temperature range?
Deglazing pads? - What glaze if the pad is designed for the temperature range?
Cooling? - Over heating won't be an issue if the pad is designed for the temperature range.
Better initial bite? - I have more than enough with the pads I use.
Better drying after driving thru water? - A slight brake pressure will fix that

What else?

The OP asked what we preferred. I prefer plain for the reasons I gave.

 

Better initial bite: You are admitting that slotted offers better bite. Saying you don't think you need it because you have enough as is doesn't change that.

Drying: Adding brake pressure will fix it, but you have to worry about it less with slotted. Once again, doesn't matter if you think it's important or not, slotted does it better.

 

Does the drying power of the slots enough to eliminate the need to dry the rotors? In other words, do you still need to tap the brakes? I certainly would, regardless of the rotors I use.

Initial bite, I say I have enough because I can lock the wheels if I brake too hard before the height transfer is initiated. There is zero gain on my application in that situation. I'd still have to wait for the car the settle itself before I can maximize my braking.

These certainly don't justify, IMO, the extra expense of slotted rotors. The extra wear on my already short lived pads is not wanted either.

I've said it before, other applications can work. The main reason most people eventually go with drilled or slotted is aesthetics. Which is perfectly fine. An other one, for slots, seems to be to extend the performance envelope of a inadequate pad. That's ok also I guess.

 

I can't help but think that if I had said "Slotted rotors are the best thing eva'", nobody would have said anything against me...

Certainly no comment in the lines of "Well in certain situations, plain (or drilled) would be preferable"...

lol

 

I read a recent review of the ipd volvo s40 in SCC that complained of a whooshing noise from the brakes. They attributed this to the addition of slotted rotors. Any truth to this?

 

I read the whole thread; good info. Thanks guys.

 

GREAT INFO NOT GOOD INFO !!

 

Good post. I didn't mean to attack you before, just diagreeing with some of your reasoning and adding a little humor - my apologies if it came across that way.

 

This issue is always a toss-up IMO. My next set will most likely be a quality set of drilled rotors.

I would just recommend you stay away from EBC rotors from my experience. They are slotted and dimpled, but make a ton of noise. Most notably while driving.

 

slotted rotors FTMFW all day. its been proven that drilled rotors crack under track conditions. =D but if you just drive your car on the street and dont auto x then who cares. imo slotted

 

no, what's been proven is that no name rotors by no name manufacturers, no matter slotted, drilled, or solid are not trackable...and that a quality rotor, from a quality manufacturer, is. Please lets not get into a slotted vs drilled debate...there are plenty of cars....track cars, that use a drilled rotor, plenty of factory sports cars that come with them, where people track them, and aren't cracking rotors left and right.

Stick to a known brand, and get pads that will play nicely with the rotors you intend to use, and you'll do just fine

 

+1

I have all drilled on all 4 rotors, but it's for show only...

 

The "Porsche 911 Story" by Paul Frère states otherwise, "...these drilled discs ran cooler, were noticeably lighter and provided better wet weather response, as any water was forced into the holes at the first application of the pads." He also said, "Instead of being part of the disc casting, the holes were drilled and their extrememities recessed for better evacuation of brake pad dust which was prone to be baked and to clog the holes."

Therefore, Porsche does not include drilled rotors purely for looks and the holes in their discs are drilled, not cast.



People are quick to point out that drilled rotors crack. Actually, all rotors are prone to cracking. Above is one of my own rear non-Brembo 350Z rotors. I replaced my rotors around 52,000 miles. Notice the giant crack through the drum area, obviously damaged by heat from the emergency brake. Drifting is hard on e-brakes.



Here is another image of cracks on the contact area of a plain rotor. People are quick to point out that drilled rotors are prone to cracking. However, what do you think the specific threats of a cracked rotor really are? Exploding rotors? Instant wheel lock up? I doubt it. Probably a little extra brake lining wear. Whoopty doo.

 

Are there any "drilled" rotors where the holes are actually cast not CNC drilled?