[Cloud9...68]

<!--quoteo(post=76262:date=Jul 28 2009, 09:31 AM:name=Jim Child)-->QUOTE (Jim Child @ Jul 28 2009, 09:31 AM) <{POST_SNAPBACK}><!--quotec-->I use regular non drilled, non slotted rotors on my race car. I tried drilled rotors, and quickly developed severe cracking around the holes, so much so that I was not comfortable running them. Plus they cost more, and provided no benefit that I could detect.

I also tried a set of slotted rotors. One of those developed the most severe crack I've ever had - a giant crack from the hat all the way to the outside edge. Luckily I felt it in the pedal right away and got off the track. I can't directly attribute the crack to the slotting, but it left a bad taste in my mouth. Besides, I couldn't detect any benefit from the slotting and they cost more.

Since then I've come to the conclusion that for me plain old non-slotted, non-drilled factory 944 Turbo S rotors are the way to go. For those of you who have seen any of my videos you know that I don't have any problems making aggressive passes under heavy braking. I view braking as one of my car's primary strengths. Why should I pay more for rotors that don't last as long and provide no detectible benefit?<!--QuoteEnd--><!--QuoteEEnd-->
Because they look kinda cool? [img]style_emoticons/<#EMO_DIR#>/blink.gif[/img] Kidding - you make very valid points, and your results speak for themselves.

Partial Post: Please Login or Register to read the full post.

[flash]

i spent some time today in a parking lot looking at cars with drilled rotors - i found quite a few - 911s, vettes, bmws, yada yada - not one cracked rotor

but again, these were street cars

next time i'm at the track, i'll do the same thing

i think a lot of the problem is the weight of the car and the size of the rotor - heat buildup is serious on these big heavy cars, and our rotors aren't very big, and have very little ducting to help them - they also are straight vaned and not directional - none of that helps things much

Partial Post: Please Login or Register to read the full post.

[Scott Collins]

I have drilled rotors, front and back, with the OEM Porsche pads. The box says Pagid. Crazy dust producers, but I think the car stops better then anything else I have ever driven on the street. It's phenominal! I clean them once a week because the rims get black. But, a few months ago, I had the same rotors but was using Metalmaster pads. Our Toyota Avalon had better braking performance, and that's not modified in any way.

So for street, I have to believe that the pads are what make the most difference. And having paid more for the drilled rotors, I sure hope they are just a bit better than anything else...

Partial Post: Please Login or Register to read the full post.

[Lord_Galva]

Wow!

Didn't think that this post would attract so much attention. [img]style_emoticons/<#EMO_DIR#>/tongue.gif[/img]

You know what? I really wanna do a brake test during the next 968 gathering.
We can do head to head brake set ups.
0-60-0 tests, comparing brake pads and brake set ups to see if we are getting our moneys worth out of them.

Partial Post: Please Login or Register to read the full post.

[flash]

that would only work if we could get cars that are the same weight, and have the same wheels, and tires

Partial Post: Please Login or Register to read the full post.

[333pg333]

I too had a set of OEM drilled rotors for a Turbo 964 mk II, and they cracked to the point of them being dangerous within 3 trackdays. I will say that having the holes vs stock certainly helped in terms of improving the feel and helping the gas buildup escape. I am going to use slotteds next.

Partial Post: Please Login or Register to read the full post.

[SeanD]

I am currently running OE 993 RS cross drilled but would prefer to use slotted as I think they last an perform better on track. Probably going to swap to Alcon slotted which I use on my 911s this winter. However if you keep good cooling on cross drilled and you are not doing endurance racing you will probably not notice the difference.

Partial Post: Please Login or Register to read the full post.

[Julian Allen]

When I raced 6 or 8 events a year in the 944 turbo S I used factory 965 rotors in the front (drilled) and M030 rears (drilled). Four inch ducts to shaped aluminum hats for cooling the front. Pagid blacks and silvers. Lots of small 3-4 mm cracks, none worse than that, and I tossed the rotors when the pads grooved them so new pads wouldn't bed easily. I was pleased with them.
The new car has somewhat larger brakes, but the initial rotors I'll try will be Brembo drilled racing rotors. Probably will also try the Brembo slotted ones. We'll see.
By the way, on the front rotors, the vanes are curved and the rotors are therefore directional.

Partial Post: Please Login or Register to read the full post.

[mattipuh]

<!--quoteo(post=76262:date=Jul 28 2009, 05:31 PM:name=Jim Child)-->QUOTE (Jim Child @ Jul 28 2009, 05:31 PM) <{POST_SNAPBACK}><!--quotec-->I use regular non drilled, non slotted rotors on my race car. I tried drilled rotors, and quickly developed severe cracking around the holes, so much so that I was not comfortable running them. Plus they cost more, and provided no benefit that I could detect.

I also tried a set of slotted rotors. One of those developed the most severe crack I've ever had - a giant crack from the hat all the way to the outside edge. Luckily I felt it in the pedal right away and got off the track. I can't directly attribute the crack to the slotting, but it left a bad taste in my mouth. Besides, I couldn't detect any benefit from the slotting and they cost more.<!--QuoteEnd--><!--QuoteEEnd-->


This was new stuff to me, that slotted can also break..! I planned to get slotted 2-piece design discs, just to save weight...
Then again, if car is often tracked, one must be more cautions with the disc condition. I have currently small cracks in front rotors aswell, but don't think they'll cause any problems if not seriously tracked. We'll see how they change after DE on 2nd weekend on Sept.

Partial Post: Please Login or Register to read the full post.

[wjk_glynn]

<!--quoteo(post=76350:date=Jul 29 2009, 12:07 AM:name=Lord_Galva)-->QUOTE (Lord_Galva @ Jul 29 2009, 12:07 AM) <{POST_SNAPBACK}><!--quotec-->Wow!

Didn't think that this post would attract so much attention. [img]style_emoticons/<#EMO_DIR#>/tongue.gif[/img]

You know what? I really wanna do a brake test during the next 968 gathering.
We can do head to head brake set ups.
0-60-0 tests, comparing brake pads and brake set ups to see if we are getting our moneys worth out of them.<!--QuoteEnd--><!--QuoteEEnd-->

One thing to bear in mind between "stopping" tests (like 60-0) and "braking" tests (e.g. track fade) is that tire adhesion is typically the limiting factor in stopping tests, and not overall brake capacity.

Karl.

Partial Post: Please Login or Register to read the full post.

[wjk_glynn]

<!--quoteo(post=76126:date=Jul 25 2009, 07:27 PM:name=Lord_Galva)-->QUOTE (Lord_Galva @ Jul 25 2009, 07:27 PM) <{POST_SNAPBACK}><!--quotec-->...Now finding slotted disks for a 968 is another problem. [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]<!--QuoteEnd--><!--QuoteEEnd-->

Paragon Products has them: http://www.paragon-products.com/porsche_92...discs_s/256.htm

Karl.

Partial Post: Please Login or Register to read the full post.

[firefish]

I'm fitting (as soon as my lines arrive from Pete) S4 rotors. They are not drilled and the vanes are curved. In addition to this I have mounted brake cooling hose mounts from Lindsey at the spindles (Ferrari uses the same design and I am yet to drive a Ferrari with bad brakes). This should take care of my brakes. If not the next upgrade would be to score a set of ceramic rotors to keep the unsprung weight at a sensible level.

Partial Post: Please Login or Register to read the full post.