I'm considering buying brake discs for my stang which is a daily driver and I'm looking for advice. What's the difference between slotted discs,cross drilled discs and discs that have both? I know what they are and how they look but what's the difference performance wise? Is one subject degrade faster? Is the myth that cross drilled brakes are weaker true? What do you have and what do you recommend?

 

slotted and crossdrilled rotors just allow the brake pads to stay cooler.

some say crossdrilled crack often because of the rotor being weakened from all the holes in it.. often times they do crack. It depends on how you drive.

slotted help keep the pad cooler and dont crack

I'm going with powerlot slotted rotors when the time comes.

 

Cross-drilled rotors help heat escape during hard braking. Slotted rotors help remove gasses from building up during braking, giving a better clamping force between the pad and rotor. Rotors that have both, do both.

Cross-drilled rotors ARE weaker... they have to be... less material. But in a daily driver situation? No, they are fine. The Rotorpros rotors have both. Do they help? Maybe. I don't care, they can't hurt. I'm sure they help some heat escape, and I'm sure they help with the gasses building up, which should help with more even pad wear.

They look a HELL of a lot better than the stock brakes... and they are a HELL of a lot cheaper then other aftermarket brake kits.

Get a quote!

 

How much are the rotopros and do they rust like the stock ones?

 

Click the link above to get a quote for all 4.

I got mine with Powder-coated black hubs and vents. They rust where they were not powder-coated and where the pads don't hit. So, before putting them on, I painted these areas with high-temp brake black paint and they still look good.

You'll have to ask Bill if the Zinc coating he got is rusting. Zinc coating is $30 more, I think.

 

The problem (or risk associated) with crossed drilled rotors is the holes can create fatigue stress risers ... so what you eventually see develop is fatigue cracks, which is different from failure due to weakness. The actual casting design can play into how fatigue resistant or lack there of pans out. There is no doubt, slotted rotors work well and are very reliable (if done correctly).

I would presume reliable manufactures that sell cross drilled rotors have made some rotor design considerations to mitigate stress riser effect ... as opposed to buying a white box generic rotor and having your favorite machinest cross drill it for you. The former are going to be held to federal and industrial standards and requirements, the latter not.

 

Thanks for all the info.

 

I'll echo what has already been said above. Lots of people will tell you that cross-drilled rotors are weak and will crack, but the fact is that unless you take the car to an autocross/road course and track it you shouldn't approach the limits of a cross drilled rotor, and should be fine.
That said, I'll throw in my $.02 and give a vote for Stop-tech rotors and kits. They range from $399 to $2100 for anything that wouldn't be overkill for a daily driver. Brakes are one area you don't want to try to save money. Do it right the first time and you'll end up ahead of the ballgame in the longrun.
Zinc wash will help prevent rust, but the swept area of the rotor will eventually wear off and probably rust if left for any extended period of time. There should be a few threads on brakes in here somewhere, just do a search. Also "Lokius" is very knowlegable about the subject, try shooting him a PM.

 

My turn...

Rotorpros are the best deal around. You don't necessarily have to spend alot to get quality rotors. Just Google Rotorpros and see what others have to say about them.

I paid $330 delivered (in CA) and included color matching the hub for an addt'l $20 (otherwise the hub would come powdercoated in black).

They Zinc plate the entire rotor and then custom high temperature coat them any color. In my case, I had them painted silver to match the Zinc coating.

btw- No rust anywhere yet.

 

Sorry for my ignorance on the subject but is "the hub" that smaller disc in the center? Is that smaller disc even visible once the tire is on?

 

Yes and yes (depending on wheel design).

 

Yes and Maybe...lol. Yeah the "Hub" is where your axle studs connect through the rotor. For higher performance brake kits this is a good place to save weight, so they tend to use an aluminium "Hat" that is then connected to the rest of the rotor by studs/bolts. This also allows the rotor to "float" freely (or expand and contract) as you heat it up.
The hub will show through on most wheels. To be honest, for most people a brake upgrade is primarily a "dress-up" item vice purely performance. A nice set of cross drilled and/or slotted rotors that can be seen definitely give a performance look to a car.
It really depends on what you want to do with your car. Like I said, ask around and find out what companies are preferred in the price range you want to spend.

The Stage II kit shown in the link below, I think is one of the best "Bang for the buck" kits out there:

http://www.brenspeed.com/mustang_2005/brakes.html

Frank