Slotted Rotors

[426 Wedge]

Time to do the brakes and want to install slotted rotors. Who sells decent ones. I want to stay away from the "China" stuff!

[WildBillyT]

Powerslots seem nice. I have a set but haven't run them yet.

[Rich189]

Powerslots are nice so are Wilwood and Baer. I had powerslots and Wilwood on my mustang a couple years ago and both were great (wilwood was better but also more expensive). Right now on my ta i have the cheap ones from ws6store and they arent as good as the other ones but half the price and they are holding up well

[EchoMirage]

keep in mind slots are just for looks. dont do anything to help you stop better.

[Predator86]

Originally Posted by EchoMirage

keep in mind slots are just for looks. dont do anything to help you stop better.

very true...and stay away from drilled rotors if u can

[cdacda13]

Originally Posted by EchoMirage

keep in mind slots are just for looks. dont do anything to help you stop better.

Wait, I thought drilled rotors were for looks mostly?(besides allowing air to go though the rotor thus cooling the rotor, which isn't really necessary on street cars.) I was under the impression that slotted rotors help the pad 'catch' the rotor better.
Have I been lied to my whole life?

[SupermanX24]

yeah I thought drilled rotors were good. They kept cooler and are lighter than OE. Guess I was told wrong? lol

[EchoMirage]

drilled and slotted are both useless for actual stopping. read up on the stickies on tech. years ago, 10 or more, pads were made differently, and produced gasses when under heave braking. the gas would actually build up between the pad and rotor like a cushion, called outgassing. thats when drilled/slotted rotors worked. now, pads, ALL pads (at least high performance ones) are made completely different. they dont make the same gasses which produce outgassing. now, all holes/slots do is take away from the surface area that you need for maximum braking.

the holes are prone to cracking, unless the holes are actually cast into the rotor, as apposed to just drilled through. the slots take away from surface area, hence reducing the effectiveness of the pads. the most youll see in actual race cars are some very slight, very shallow slots, or a wave pattern around the circumferance of the rotor. this is only to help clean the pad/rotor, or something to that effect.

case in point: when i went to the IROC auction, they had rotors on shelves. the short track rotors, made for constant braking from 100mph down to 40, over and over again, were solid, blank rotors. carbon fiber, yeah, but solid blanks.

[SupermanX24]

so what kind of brakes would you recommend once I start my road racing project?

edit: sorry 426 Wedge I kinda took over without realizing. lol

[Tru2Chevy]

High quality solid blanks....Brembo makes 'em for a pretty good price.

- Justin

[EchoMirage]

Originally Posted by SupermanX24

so what kind of brakes would you recommend once I start my road racing project?

depends on your budget and what you want to do with it. id highly suggest brake ducts, regardless of rotor choice. anything is better then nothing. i made some out of nothing but 2.5 in. wetvac hose and zip ties. it helped when i did the e-town HPDE. this winter when i do the C5s, ill try and improve on it.

you could get brembos, with ducts, and be done with it. or; you could get cheap rotors, with or without ducts. use them once or twice (per road course day) and toss them. you may end up with a warped rotor....never know. if you warp a brembo, youre out a decent amout of money. if you warp an autozone special, youre out alot less, and get brand new rotors with each swap.

dont forget the pads also, theyre more important then the rotors. if you want one pad for driving/track, go with either hawk HPS or HPS+. if you dont mind swapping pads, bleeding brakes for every track day, then get a dedicated racing pad, like ferodos or the like. check out FRRAX and the roadrace section of ls1tech for more info.

[SteveR]

I ran powerslots for a few years and loved em. Never had a problem with them.

With the drilled rotors, the holes have a tendency to crack and brake over time. Good for a race car where you see limited use and you change them often. They keep the brakes cooler when racing, but no need on the street.

[Fast92RS]

If drilled is not good then how come I see a lot of Mercedes coming stock with them. How are they different?
I ran powerslots on my old truck they were good but dont have them resurfaced when its brake time. I resurfaced them when I worked at the dealer and only took off a minimal amount and after a little bit of driving they warped and I had to replace them with new ones.

[1QWIKBIRD]

Originally Posted by EchoMirage

......if you want one pad for driving/track, go with either hawk HPS or HPS+.....

I run this combo on my firechicken. C5 conversion up front with HP Plus upfront and HPS pads out back, both on factory type rotors. They perform double duty quite well. Cold braking is excellent and I've never had a problem with them while auto-xing. I have yet to do a track day event with this combo, but that is in the near future. The HP Plus pads do dust quite a bit even in normal driving and the dust is kinda tough on wheels so you gotta keep them clean. The beauty of the C5 upgrade is the almost limitless brake pad compounds that exist for them, so choices are plenty. The upgrade is easy, straightforward and uses all factory parts, so getting replacement parts is easy. There are several different companies that make the conversion bracket. Downside to the C5 conversion, weight. Its a heavy combo and requires 17" wheels.

I have the TrackBrackets and its a very nice setup, there are 2 or 3 other suppliers that provide brackets for C5 conversion. Here's a link to get you started http://www.ls1tech.com/forums/showthread.php?t=353903

To give you an idea of the kind of temps you can see on a track day, the previous owner of my car 2MCHPWR (on this board, maybe he will chime in) melted the WS6 center caps out of the front wheels on my car at Pocono when he first started doing track days, that was prior to the C5 upgrade.....That's a lot of heat.

Chris

[sweetbmxrider]

that is an excellent read. thanks 1qwikbird!

[Jam]

china rotors should only be used on cheap cars. I'm installing them on my sisters Chevy Malibu. You can't even get those rotors shaved off if they warp; they'll just crack.

[Jam]

Originally Posted by sweetbmxrider

that is an excellent read. thanks 1qwikbird!

yeah great information .

[Jam]

Originally Posted by EchoMirage

keep in mind slots are just for looks. dont do anything to help you stop better.

slotted rotors actually dissipate heat faster than standard rotors. SLOTTED ROTORS FTW. cross drilled IMO is just for looks. They tend to crack easier and due to our new technology of resin brake pads the need for a CD rotor is obsolete. Also, CD rotors limit the amount of contact that the break pads have on the rotors creating less of a stopping power. I'm sure there are some great CD rotors that do not crack, but I would just stay away from them in general.

[BonzoHansen]

Originally Posted by Fast92RS

If drilled is not good then how come I see a lot of Mercedes coming stock with them. How are they different? .

Just because an OE runs something that is easliy visible doesn't mean it it effective on the street. Just see wings for an example. Or 19" and bigger wheels. It's blingalicous.

[Fast92RS]

Originally Posted by BonzoHansen

Just because an OE runs something that is easliy visible doesn't mean it it effective on the street. Just see wings for an example. Or 19" and bigger wheels. It's blingalicous.

I kinda figured that but do they have the same problems with cracking or do they use good quality. Even my buddies Mecedes has them stock and his is one the cheapest mercedes they make. Im just wondering.

[BonzoHansen]

I am told that some rotors have the holes cast and some are drilled, and that makes a difference, with drilled being prone to cracks. I cannot confirm that.

[sweetbmxrider]

Originally Posted by JamZ28

slotted rotors actually dissipate heat faster than standard rotors. SLOTTED ROTORS FTW. cross drilled IMO is just for looks. They tend to crack easier and due to our new technology of resin brake pads the need for a CD rotor is obsolete. Also, CD rotors limit the amount of contact that the break pads have on the rotors creating less of a stopping power. I'm sure there are some great CD rotors that do not crack, but I would just stay away from them in general.

you obviously didn't read that link. slotted/drilled rotors suck now-a-days. they used to vent off-gas from the resin used on old pads. now, it is just for "looks". just read the article and learn some!

[BonzoHansen]

Just one of many related articles out there on the web…

http://www.stoptech.com/tech_info/wp...lections.shtml

DRILLED VS SLOTTED ROTORS
For many years most racing rotors were drilled. There were two reasons - the holes gave the "fireband" boundary layer of gasses and particulate matter someplace to go and the edges of the holes gave the pad a better "bite".

Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages.

...some related notes...

…The brakes don't stop the vehicle - the tires do. The brakes slow the rotation of the wheels and tires. This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use - which, in the case of aftermarket advertising, may or may not be the ones originally fitted to the car by the OE manufacturer……....In order to brake effectively, the tires must comply with and grip on the road. Your braking system is no better than your tires and suspension. The best money that you can spend is on really good tires and really good shocks.

...my 77 is a prime example of this...despite the 12" rotors and Porterfield pads & shoes...it is severely under-tired with heavy wheels...

INCREASING DISC DIAMETER
The problem with increasing the effective radius of the discs is that, since the designers used the largest rotor that would fit inside the wheel. Typically, increasing the rotor diameter means increasing the wheel size. The expense involved is only one objection. A major issue is the impact on of the OE suspension geometry.

The camber curves and roll resistance characteristics of any proper suspension system are designed for tires with a specific sidewall height and stiffness. Increasing the wheel diameter means decreasing the sidewall height and the compliance of the tire. Carried to an extreme, this will hurt cornering capability and might actually result in a loss of braking traction due to "edging" the front tires under heavy braking. And although technology is making possible ultra low and stylish tire side wall heights, it does not necessarily result in ultimate performance, just take a look at the sidewall height of Formula One and Indy cars.

...like I mentioned, going bigger than 18" (or even 17s) is a point of diminishing returns due to wheel weight and tire design/dynamics....

[wretched73]

I heard that slotted rotors actually held brake dust and what not and cause the rotor to crack.

[WildBillyT]

Originally Posted by BonzoHansen

Just one of many related articles out there on the web…

http://www.stoptech.com/tech_info/wp...lections.shtml

This should be required reading in this section. There is plenty of great info on here, especially regarding things like warped rotors, fluid type, pad area, etc. I think the author worked on the GT40 teams back in the 60's so he's been around...