Slotted/Cross-drilled Rotors

[DLTARNU]

I've been reading about slotted and cross-drilled rotors trying to find out if they offer any performance advantage.

The best I can find is that slotted rotors help channel away water from the surface so there isn't that second of "oh crap" when you hit the brakes in the rain.

I've been thinking about getting the Eradispeed rotors if they offer a performance advantage, but I get the feeling it's almost, if not entirely, an aesthetic upgrade.

Does anyone have real-world tests between stock Gen II rotors versus the aftermarket rotors? 60-0 distance, 100-0 distance, etc.


Thanks!

 

[Bill B]

I have the Eradispeed's on my car. They take the track abuse allot better than the stock setup. The primary reason for slots are to vent hot gases.

 

[Bob D]

I had a set on my car for a couple thousand miles and went back to stock. I didn't like the rough feeling they had on hard braking.

 

[Chuck 98 RT/10]

I don't think you'd notice much stopping distance advantage between rotors. The advantage performance rotors give is primarily in cooling.

 

[Janni]

And get slotted - NOT drilled. Drilling weakens the rotor. It's a poser mod. (Unless the holes are CAST into the rotor - and FEW manufacturers do that....)

 

[DLTARNU]

Has ayone tried the EBC Dimpled and Slotted rotors?

Parts Rack has them:

http://partsrack.blastmart.com/customer/product.php?productid=615&cat=98&page=1

I'm wondering how they stack up against Eradispeed; not too sure how that color will look, either.

Janni, if what you say about crossdrilled rotors is true, the same shouldn't hold true for dimpling, should it?

Here is what I want out of new brakes, in this order of importance:

1) Reduced brake dust (already bought EBC Greens)
2) Better stopping power (stock rotors seem to heat up too quickly - anyone else notice this?)
3) Improved looks (I don't think stock rotors look bad, but if not giving up function for form, might as well look good, too)

While the stopping distances of the stock brakes are good enough for me, I wouldn't mind a little distance shaved off my ZYX-0 time.

I was out at the roads around Homestead race track goofing around with a friend and I did a 100-0 brake slam. Worked great the first time; gum almost came out of his mouth

But I tried again maybe 30 seconds later and the braking distance was considerably worse. Then again, I'm not a racer, so perhaps this should be expected. Any trackers care to clarify?


Thanks!

 

[CitySnake]

And get slotted - NOT drilled. Drilling weakens the rotor. It's a poser mod. (Unless the holes are CAST into the rotor - and FEW manufacturers do that....)

Interesting point Janni. Can you name any of "those" manufacturers?

 

[Bill B]

[/QUOTE]
Interesting point Janni. Can you name any of "those" manufacturers?

[/QUOTE]

Porsche is one of them.

 

[Chuck 98 RT/10]

Here is what I want out of new brakes, in this order of importance:

1) Reduced brake dust (already bought EBC Greens)
2) Better stopping power (stock rotors seem to heat up too quickly - anyone else notice this?)
3) Improved looks (I don't think stock rotors look bad, but if not giving up function for form, might as well look good, too)

If you want #1 then you'll have to sacrifice #2. The single most effective thing you can do to reduce stopping distance is pad upgrade. EBCs are the best pad on the market for reduced brake dust. Unfortunately they are probably the worst pad for stopping. I run EBC on my street car. PFC01 on my track car. If you want to stick with EBC add steel braided lines for a little more stopping power. Not sure how much you'll notice it though.

Get your EBCs from Steve Pasztor GreatBrakes.com 972-743-9443. His service ranks up there in Tator and Levin status. I get my PFCs from Larry Macedo 407-246-6511 - another great service tuner/supplier.

If you go with #3 pleeease get a two-piece rotor that at least looks like a track rotor and not a bling job. But it's your car, do what you wish.

 

[Mike 99ACR]

I have the Eradispeed rotors and like much better than stock. When I track the car I use Motul fluid, cooling ducts, EBC yellows, and the car has SS brake lines. Once these pads heat up they seem to work fine.

I will admit I did get them for the looks. With my ACR wheels they just look like the type of rotor that should be on the car. In fact I had the hats on them anodized blue which for the front was kind of a waste because of heat fade.

If your going to track the car alot I would suggest 14" rotors and larger calipers with the very best pad for your fastest lap times and to be much more competitive.

 

[DLTARNU]

Do the Eradispeeds make braking rougher, as a previous poster stated?

 

[Bill B]

It's more the pad than the rotor.

 

[Chuck 98 RT/10]

I will admit I did get them for the looks.

Nah, you track it Mikey. Sebring Aug 28???

 

[Sniper]

I've got the Eradispeeds with EBC greens and I didn't notice really any difference one way or the other.

Negatives = 0

Positives = 2 No brake dust
Looks awesome, makes stock look sick

And as far as weak rotors, just check out their warranty, speaks for itself.

WAR POSER HATERS

 

[Chuck 98 RT/10]

WAR POSER HATERS

LOL. Matt, be quiet, sit back and take it like a man.

 

[Mike 99ACR]

Do the Eradispeeds make braking rougher, as a previous poster stated?

Not on my car, if so I would have replaced them before I used them braking at 130-135 mph at Sebring.

 

[Tom F&L GoR]

Ummm.... I'll argue that stainless braided lines don't help stopping power. They may reduce the time for initial pad-rotor contact or improve pedal feel by reducing brake line ballooning, (allowing you to modulate better) but they don't assist the pad-rotor friction, heat rejection, or tire-road friction.

 

[luc]

Janni is 100% right, some of the manufacturer of cast holes are mostly from Europe,as Porsche,Ferrari,Audi,some BMW and Mercedes,etc.

To understand the benefits and drawback of slotted or "holed" rotors, a quick explanation of the way pads and rotors work is nessecary.

Obviously, when you push on the brake pedal to slow dow a car, friction is created between the pads and rotor with heat being (beside slowing down)the result of it.

During this process, pads will be "gasing out" meaning a layer of hot gas will be created by the rotor/pad heat and friction and this layer being between the pads and rotor, it is easy to understand that you don't have a "full" contact between the pad and rotor and friction is reduced.
Good for bearing or piston rings, bad for braking.

The slots in the rotor are designed to scrub and remove this layer of gas.
Most racing pads also incorporate at least 1 slot for the same reason.

"holed" rotors serve a triple purpose, to remove this layer of gas, to help in cooling the rotor and in removing unsprung weight.

Slotted rotors have no drawback that I know of but "holed" rotors have a major one, those holes reduce the surface aera that is available for contact between the pad and rotor, less surface = less friction = less braking.

On a street car, save for the "look" factor, nobody really need slotted or "holed" rotors, on the Autobahn in Germany, with no speed limit, I could see how they could be helpfull,after all, there is a reason why most of the cars that have them from the factory are Germans,save for the Ferrari.

Luc.00GTS

 

[Chuck 98 RT/10]

I tend to agree with you Tom. That's why I said "Not sure how much you'll notice it (steel braided) though."