cross drilled? slotted?

[Mustang5L5]

So the 911 turbo, corvette Z06 and other supercars all have drilled/slotted rotors. It's just for show?

Yes and No.


The deal with crossdrilled rotors is the release of gases created when brakes are applied. Now, modern car pad materials DO NOT release gas. SO that means crossdrilled rotors on a street car are useless and just for show.

But, modern supercars sometimes run more aggressive race style pads that DO release gas, so they are needed in that sense.

Also, these cars all run 13" and 14" brake systems. The crossdrilled holes are there to eliminate weight from these heavy rotors. Since the brakes are so big, they can afford to lose a little mass.

WIth normal cars, we deal with puny 10" and 11" brakes. Crossdrilling the rotors removes mass which is used to cool the rotors down. WIth less mass to absorb the heat generated, the rotors warp and crack and you have problems.

Baer and Brembo do cast good crossdrilled rotors fur the use of aggressive street pads.

Anyway to make a long story short, on street cars, you can run crossdrilled...especially the 13" rotors. There is enough rotor to stop your car, but don't expect performance gains from it. In race applications, stick with quality solid faced rotors.

 

[5.0zone]

How much do you want to spend? So if I read this correctly you have an 04 GT that you have worn the rotors out already? You must do some hard driving.
You may want to consider the Baer kit with 13" rotors front and rear, I think it runs about $1100. This setup uses the new larger PBR caliper up front with 13" rotors and the stock caliper in the rear with an adapter and 13.25" rotors.
I'm running the Baer rotors 13" front/13.25" rear but with Bullitt calipers in the front. All this plus new brake lines in front and new pads for the rear ran less that $1000.

 

[timeless2]

Cobra upgrade is the best for your application, in my opinion. I don't like perforations of any sort in a piece of hardware that is designed to slow me down with its surface area.

 

[Mustang5L5]

The thing about the Baer 13.25" rear kit is that it's a solid style rotor and not a thicker vented style rotor. It does a great job on a street car filling up 17" and larger wheels, but it isn't really ideal for performance braking. It's thin (only about 1/2" thick) and any serious heat will warp it. Baer is the only place to get new rotors and i'm not even sure they sell them separate.

Also, some guys have expeirenced losing the power with their e-brakes due to stretching the cable for the larger rotors and also problems with noise and chatter with the calipers extended so far out.

The Ford FMS-2300-M Cobra disk kit is cheaper ($190) and uses a vented Cobra 11.65" rotor that will outperform a solid style rotor. The kit also reuses the stock rear calipers.

Baer does make crossdrilled rotors for the Cobra in 1 and 2 peice versions. You can pick up the set of 4 Cobra crossdrilled rotors for about $450. The 2-peice versions will run you about $950 front and rear.

 

[04gtdrop]

all very good info here. thanks a bunch guys, looks like it will be time to make a descion very soon.

the deal is she was bought back in march of 2004 and she has 26...ehh almost 27k miles on her already. she is a DD and during the day, i hit a lot of stop and go traffic on the freeway. some times you really get moving... then BAMM.... you gotta stop cuse the fool in front of you. or the jack@$$ in front of him slammed on his brakes.

so i need something that will stop me FAST but still be able to put up with the heat... thats why i thought about the slotted only.

my commute to work is about 4 miles one way = 5-10 min.

my commute to school is about 28 miles one way = 45 min to an hour during the day and like 20-25 at night (no traffic at 11pm heh)

so im trying to find a good balance.

since im tight on cash i think my options are limited, i only have about 400 ish (maybe 500, but thats pushing it) total. this will include all four rotors, pads and S/H charges.

i thought about power slot and baer. but i dunno.

i wish i could do an upgrade, but i dont have the funds to do so right now.... that will have to get put on the back burner along with everything else

thanks again SN

 

[Silvr04GT]

k, well since your front brakes do most of the work here's a kit that should fit your budget hand selected by me!

Calipers - http://www.stangsuspension.com/store/comersus_viewitem.asp?idproduct=262 ($229.95)

Rotors - http://www.stangsuspension.com/store/comersus_viewitem.asp?idproduct=554 ($169.95)

Brake Lines - http://www.stangsuspension.com/store/comersus_viewItem.asp?idProduct=920 ($59.95)

Grand Total - $459.85 + shipping

The install on front brakes is supposed to be very easy I've haven't done it yet, but that should get you right under the $500 budget.

EDIT - The calipers come with pads already.

 

[Mustang5L5]

You can use your original front brake lines if you are on a tight budget.

All you need are rotors and calipers.

I agree that the front do most of the work so don't worry about upgrading the rears.

 

[04gtdrop]

hey why are the bullit calipers better than the gt or cobras? what size are they?

now im wondering if i should hold off and get new calipers?

 

[Mustang5L5]

Bullitt calipers ARE Cobra Calipers.


Cobra/bullitt calipers must be used with the 13" Cobra rotors.

They are better because 13" Brakes are bigger than 10.9" Brakes

 

[tomustang]

add - most of those big 13-14 inch performance systems (ie: porsches) run complete ceramic brake systems slotted/cross drilled.

 

[wms004]

There is a lot of debate over slotted vs. drilled vs. drilled & slotted. Drilled rotors have a tendency to crack (between holes) more than a slotted, which is how I made the decison to put slotteds in the rear (even tho the rears only do about 15% of your braking anyways). Slotted rotors have a different way of keep the rotor cool by escaping head build up as well.

Anyways, I am against slotted and drilled because you are losing too much friction contact space. The pad has less to grab onto. Sure they may fade less, but if you think about it, a rotor with more surface area to grab should provide better braking characteristics in normal driving situations.

Here's my combo.


Cobra Kit w/ 13" Brembo

Brembo Slotted Rears and Hawk HPS Pads (no noise)

-Wade

 

[04gtdrop]

ok, so i got bullit calipers up front with cross drilled/slotted rotors (and pads) for 375 shipped. was that a good deal? i thought it was, next time i have a few extra bucks i might upgrade my rear rotors to slotted. but i was able to stay with in my budget. i'll let ya know how the install goes and how they fell after i put them on.....thanks for all the input guys i really appreciate it. SN came through once again....





EDIT: the only thing i didnt get was the new brake lines, but are those really that important? how will new lines help out? sorry if i sound like a newbie... but i dont know that much about brakes and suspension

 

[Silvr04GT]

ok, so i got bullit calipers up front with cross drilled/slotted rotors (and pads) for 375 shipped. was that a good deal? i thought it was, next time i have a few extra bucks i might upgrade my rear rotors to slotted. but i was able to stay with in my budget. i'll let ya know how the install goes and how they fell after i put them on.....thanks for all the input guys i really appreciate it. SN came through once again....

Good stuff bro! Did you get the stuff from StangSuspension or did you end finding somewhere else?

 

[04gtdrop]

was gonna go with stang suspension, but i ran a cross an auction on ebay. just happened to have 2 hours left with no bids, so i was like what the heck, ya know?

im excited though, my brakes have been going south really fast the past like 2 weeks. im glad you guys gave me the idea about the new calipers, i never would have thought about that on my own, plus i thought they would cost more....

well i'll let you know how it goes. one last time.... thanks guys. have a good weekend (whats left of it)

 

[Mustang5L5]

Sounds like a good deal.


When it's time to do the rear, the Cobra upgrade kit is only $190

 

[04gtdrop]

yeah thats not too bad, but i heard that people had issues with the r brake line reatching?

 

[Mustang5L5]

I think that's with the baer 13" rear brake kit that guys have issues with the e-brake stretching.

The Cobra kit only moves the caliper out about 3/4" or so from the factory spot. It uses factory parts that fit together right.

 

[DerekStangGT]

i thought Kilgore would be in here by now, telling us all how much of a waste aftermarket brakes are.

 

[pitch]

Take a look at these. www.ssbrakes.com. I am seriously considering putting these on. Great looks and from everything I've heard they are quality performers.