renvagn

Hi, I just had a fellow club member shake down my new car ( he is an instructor and had a Rothmans Cup car) and he said my brakes are awful. I plan on getting new rubber lines. The front rotors have been cut once and there is an 1/8 "- greater, lip at the top and bottom. The rears are smooth and the pads are 7,000 miles old. I think I need new front rotors and pads.

Do I go with the factory OEM...Zimmerman X-drilled (do these spider crack around the holes?)..... or bite the cost for Brembo's which I have been told are cast with the holes? As for pads....Hawk HTS + have been mentioned by many more knowlegable than I at this point. Your input is appreciated.

Epic2112

I'm pretty sure the zimmerman are cast with the holes.

Oddjob

Unless you have a reason otherwise, I would recommend going with the OEM solid rotors. If you order them from the discount dealers that advertize in Excellence and Pano, you can get the TS rotors for under $100 each, and the Porsche spec rotors are arguably better quality than the aftermarket Zimmerman.

What is your application? Street, mostly street with some light DEs, mostly DEs? Pad choice will depend on what your use will be.

A lot of things can give the feel of "awful" brakes. Soft pedal, no grab, vibration? Before spending a lot of money on pieces and parts, try to narrow down what is causing the bad feel. If you have a soft pedal, go with a good fluid flush and bleed first, then check the brake lines, master cylinder, abs pump etc. If you have vibration, check the rotors and pads (what is the current compound/brand?).

Fishey

Take rotors to machine shop + Buy new pads + Bleed brakes...

I bet that fixes the problem..

Matt H

If he has a lip that he can feel and measures as 1/8th of an inch turning them is not the proper answer. You can almost be sure that 1/8th of an inch will be below the spec. Rotors are cheap/throw away items.
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smokey

Your rotors are worn beyond spec if you have an 1/8" ridge. I've had good results with Zimmerman rotors, and Vertex sells them for about $75. Get the solid ones: the "holey" ones have no advantage, and crack anyway. I believe that Porsche rotors are Zimmerman, with painted hubs. For street and light track use, Hawk HP+ pads are good. Also for track use, the 968 M030 brake ducts are the best solution for cooling. Oh, and racing brake fluid for the track. When you change rotors, it's a good idea to put in new wheel bearings if this is an unknown car. Aftermarket bearings are cheap.

Z-man

I totally agree. OEM solid, vented rotors are your best answer, IMHO.

-Z.

Ken D

FWIW, here is an excerpt from the Technical Regulations for the Northeast Region PCA. Regarding brakes:

"No cuts or abrasions on lines, no cracks in drilled or slotted rotors. Only cars originally equipped with drilled or slotted rotors, or OEM purpose built drilled or slotted rotors are allowed. No after market modified rotors. Drilled rotors in particular are prone to cracking from heat stress. Cracks going from "hole to hole" or "hole to edge" or "hole to hub bolt" are cause for failing the car. Solid manufactured rotors cannot be drilled or slotted without compromising their safety. "

sweanders

Time to kill the myth of cast holes in rotors.
Check out this picture from Zimmermans website, who produce Porsche OEM rotors.



For pads I recommend the Pagid pads, I use the orange ones and they work great.

944Fest (aka Dan P)

Yep.. NOS rotors, cheap and one of the real parts bargains on our cars. Paragon will get them to your door asap, with a smile. If your brakes suck now, you are in for an extremely pleasant surprise once you get them bled/fixed!

Oddjob

I ordered a set of rotors from an aftermarket supplier several years ago. One showed up in a Porsche OEM box, the other in a Zimmerman box. The Porsche rotor did have the zinc coating on the hat and disc edge, the Zimmerman did not. I used this pair on an 89TS track car.

Over time, the Zimmerman rotor showed much more severe stress/heat cracking than the OEM rotor. I spoke with Bill Groeschen of the Cyro/Frozen rotor company, and he had experienced the same thing. That the Porsche OEM rotors are better quality than the Zimmerman rotors.

If Zimmerman makes the OEM rotors for Porsche, Porsche must be imposing a higher material quality spec, that Zimmerman does not meet when they sell their rotors to the aftermarket sources.

Your choice. But I would pay the extra few bucks just to have the zinc coating, let alone a better rotor. I hate rusted rotor hats, and its not worth my time to mess around painting the uncoated ones.

Epic2112

Nevermind then!

renvagn

Thanks for the help. I just canceled my Zimmerman rotors and ordered thru sunset. $5.00 dollar difference and will have the zinc coating. I am looking forward to the massive deceleration forces of the new rotors. pads and lines.

ninefiveone

don't forget to bed your pads and rotors in. It only takes a little bit of time and it makes a big difference.

luckett

I second the recommendation for HP+ pads. They can be a bit noisy on the street, but they are a great dual purpose pad and they are a great value.