Cross Drilled?
 

OK, I know this has been discussed to death, but now it's ME who's buying them and I want fresh opinions.

I need new rotors before I do my first high-speed DE in March (my birthday present to myself, btw). I love the look of the cross-drilled zimmermans, but I'm reading they should not be used for the track.

Here is my list of questions I'd like answered:

1) Is a DE event as rigorous on brakes as actual "track use" of the boxster?

2) Can I safely buy the cross drilled and not have to replace them too soon?

3) What pads should I buy for regular city and country driving with a DE thrown in now and then?

4) Should I replace the brake lines (originals on the 104k mile car now) with SS ones?

If you smart wrench-turners can help me out here, I'd appreciate it!

[1/7/08 Clarification: My pads and disks are worn and need replacement. So, this isn't a desire to upgrade for the sake of upgrading alone. I just need to get new brake component and wondered if going to cross-drilled would be ok considering I'll be doing a DE soon]

This is not specific to the 986 but based on my experiences including my 944's.

1) DE is not a race, you should never drive 10/10. So no, it is not AS stressful as a race. However, you will get those things nice and warm.

2) In all honesty, cross drilled will not increase performance enough to be worth the money. I would just buy regular stock rotors. It's not like Porsche makes weak brakes from the factory. With stock rotors you won't even have to worry about cracks. One less thing to deal with.

3) I'm a fan of Hawk pads... I've run HP+ on the 944 with great success on street and for DE use. Excellent wear and durability without eating rotors. For our Boxster S, I just installed Pagid Sport RS 4-2-1 pads. No DE on those until I get a chance to get it out this spring.

4) SS is not necessary... not as good for road use as it makes them difficult to inspect. You may just want to install new factory lines, along with a good fluid flush with something like Ate Super Blue.

If your car is only going to get light DE use, you'll be fine with new factory parts, and some upgraded pads.

They aren’t really going to do anything special. If you’re after the look go for it. The drillings have a cheese grater effect on pads so they will not last as long. Doing a more fade resistant pad would help you at your event as well as allow the pads to last longer. Remember rotors on Porsches wear with the pads so shoot for keeping the pad life long. Pagid sport pad part # Front T5106, Rear T5105(or similar compound) would work best for your situation. If you are switching compounds in the rear you will probably have to do something for the fronts as well. High speed straights that lead to tight corners are what test your brakes the most. So if you have a lot of those, an aftermarket drilled rotor in stock size will probably eventually from small cracks. All those drill holes add up to a reduction in over all rotor mass, and the more material that is on that rotor, the better it will be at dissipating heat. SS lines will make a huge difference in peddle feel.

I switched to SS lines on my 2000S and it made a big improvement on the pedal feel. It made the brakes feel like they engaged firmer at a shorter point in pedal travel. The pedal never comes anywhere near the floor now. Along with that, modulating the brakes is easier because it takes less pedal travel. BTW, I switched to ATE blue at the same time. Got a brake bleeder? It makes the job really easy.

Since this is your first DE event don't worry about having to "upgrade" anything in the car. It will be a while before the car needs to be improved because it's holding you back.

Make sure your stock brake system is in good working order. Stock pads / lines / rotors in good condition will be just fine. If your worried about the age of your brake lines you should replace them... street or track the last thing you want is one to let go. If you are flushing the brake fluid there is no harm in going to a high temp fluid like ATE Super Blue, just keep in mind you will have to flush the system more often. The stock brakes on any modern Porsche would be considered an upgraded system on just about any other car, so don't worry about it, go enjoy your first DE experience.

Marc

Re-read what Marc just posted because he's right on. If this is your first DE, you won't be held back by the limitations of the car. Cross drilled rotors are an upgrade in almost every respect. They lower unsprung and rotational mass, and the holes actually dissipate heat faster because of the airflow and additional surface area of the metal (the heat does not have to travel as far to escape the rotor). The holes also allow the gases created by the friction and extreme heat between the pad and rotor to escape easier, making braking more effective. There is the risk of cracks developing between the holes, and they are generally more expensive to replace. It's a trade off, but for now, I would say that the stock brakes in good working order will be more than enough.


And, of course, everything I just said is always heavily debated, haha :cheers:

Thanks for all the input!

After weighing the risks and rewards (wanting to satisfy that cross-drilled look for the car) I went with the following today from an Ebay seller in Toronto:

Cadmium-plated Zimmermann cross-drilled rotors ($370/set of 4)
Pagid pads ($205.00/all four wheels)
SS brake lines ($120/set of four)
Sensors ($39.95/set of 2)

A buddy will help me do the swapping out and bleeding the system. He loves to turn a wrench and does this sort of stuff in his sleep, and he's a good teacher.

I'll post pics here when I am done!

The most important thing for your FIRST DE is to make sure the car is up to it. What does that mean? Make sure your brake pads have over 50% of their available pad remaining. Also, make sure you have FRESH, NEW DOT4 brake fluid. Some prefer ATE (Blue or Gold) others spend more for Castrol SRF.

As mentioned, you will be the limiting factor in your first de.

Now, if in general your brakes haven't been reconditioned recently, it certainly wouldn't hurt to get new DOT rated stainless steel lines. Perhaps some "performance" pads (vs stock), fresh brake fluid (see above) and if you need to replace rotors, I would suggest SLOTTED over cross drilled. They are just as capable of venting away the gas build up, but they don't succumb to cracking as easily as cross drilled.

For reference, I am a PCA instructor who runs in either of the top two run groups (predicated mostly by region). For my Non S, I replaced Pads and Fluid and found the brakes better than the upgraded brakes on my previous TRACK ONLY 911.

You did EXACTLY what I would've done.

Who makes / sells slotted rotors for a non-S 986?

Check to make sure the sensors work with you new pads. Over the years, as you do more and more track/DE events, you will learn to inspect pads almost naturally and frequently and wonder why the car even came with sensors - its about being an active owner ;)

For slotted 986 non-s try frozenrotors.com. Seems like a pretty damn good price. I just paid 90$ for 4 ebrake springs, and a total of 425.00 for just the ebrake parts.

Looks like frozenrotors uses Power Slot for the 986. Started a new thread rather than completely hijacking Randall's

http://986forum.com/forums/boxster-general-discussions/14951-power-slot-rotors.html

Hi, Randall I bought the rotors from the same guy, no Cadmium-plating just got them painted silver, here's some pics, not to many holes on them just enough to quench my thirst :)

http://i167.photobucket.com/albums/u...r/Photo103.jpg
http://i167.photobucket.com/albums/u...r/Photo100.jpg

Franco, I do hope mine are directional like the ones in your pics. Another poster on the forum ordered Zimm's for his S and they are the wrong direction on one side on the front, which was surprising to me. :eek:

Hey Randall,
Good luck with that! Enjoy!! I have the Zimms crossed drilled and slotted---painted each of the hats and the brims black as a rust retardant. I bought them last year---just waiting for my brake pads to wear out and I will change them all out at once. :cheers:

P.S. Been sick with the flu since New Year's Eve! I feel like crap! :( Anyway, hope you and your family tried to make the best of the holidays! Best wishes again to you, your dad, and your fams!!