Anyone have a line on the best place to save money on Zimmerman rotors?

While we are at it, anyone use somthing different you think is better than Zimmerman?

(I'm looking for pretty cross drilled 911 disks for my 5 bolt conversion and Boxter brakes on a street driver)

S.

zimmermans are the best buy for the money and all of the local suppliers have factory cross drilled available. The cryogenic guy freezes them as well, for an additional charge. Brembo is the cheaper one. Typically the cross drilled sell in the near 100 price range each.

Just read this regarding the use of drilled roters on the street from one of my favorite web sites at the moment (http://www.carbibles.com) :




Is this true?

Yep for the most part it's true. The task of the rotor is to shed heat from the friction of the pads being applied. The more material in the rotor the better it will shed the heat. When a rotor is drilled you are removing heat shedding material so in theory you have made the brake performance less. And some experts say that drilled rotors will eventually start cracking from the holes outward. There are also rotors that have the holes cast in them, the theory being that the holes are there during the casting process and are less suseptible to cracking not sure if that's true or not. So why do race cars and some street cars have them? For race cars there is a tradeoff between performance and saving weight. And because rotors are a throw away maint. item cracking is not a concern. On street cars there is the " bling " factor that people are looking for. Remember the OEM manufacturers do not warrant brake rotors as these are " normal wear items " so they don't worry about them cracking either.

Edited: Just realized you were looking for 5 bolt rotors, but this info may be useful for someone reading this post looking for 4 bolt applications.

I can't say that I'm "in the know," but I just compared a few places to order rotors all around for myself. If anyone has comments on the service of these vendors, please share for all of us to know.

I have ordered and received parts (not rotors) from getcoolparts.com once before with no problem, and they have the zimmermans for $55/each for fronts and $46/each for rears. I think they are in AZ.

I have also had luck with www.porsche-parts-direct.com, which are a couple dollars higher but closer to me on the east side of the country.

I have never ordered from them, but GPRparts.com is in CA and they have them for 65/ea fronts and 51/ea rears.

Most of these places offer free shipping for orders over $50. You may find better prices on ebay for new parts, but check the shipping costs to see how the totals compare.

Pelican had only fronts available for around $60/ea.

Hope this helps a little.

Shawn

Makes it sound like your rotors are going to disintegrate out from underneath you... total

I have drilled rotors on both my cars. It simply helps vent the gases from under the pad. "That's" what the holes are for. Under the extreme braking conditions of racing you will probably eventually see small fractures around the holes... but then again, we're back to talking about race cars.

The writer also makes it sound like the big evil "performance suppliers" are out to take your money with total disregard to life and limb. More The fact is, the margin on rotors sucks. I could care less if I sell them or not and I could care less if they have holes in them. Personal preference. I'm a supplier... I'll mention the fact. "They can get little cracks in them (eventually, over a long period of time)." Big deal.

Drilled rotors are just fine. I know a certain automobile manufacturer that uses them on quite a few of their cars. Brake rotor failure... give me a break...

The reason I mention a street car application is that I have seen cross drilled rotors break (shatter)at the track....this is where you are always on the limit and everything is at it's greatest stress and heat levels....(or you're not going fast enough). I only use slotted rotors at the track....

BUT, my 914 will have a generous braking system (boxter derrived, thanks RICH) and as a "weekend warrior" on the street it will not get anywhere near the workout it would in a track situation...therefore I want the "look" to go with my slick brake caliper system and suspension work....I doubt if even the small cracks will develop in this situation.

Thanks for all the info on suppliers...

Cheers,

Sean

The best 'cross drilled' rotors to get are those with the holes cast. I believe late-late-late model Porsche rotors are cast with the holes.

Besides, you would have to be using and re-using cross-drilled rotors with some serious braking to make a rotor break. I've seen solid rotors develop tiny fractures whereas all the cross-drilled rotors i've seen have not, albeit this was street use not track.

I'm notorious for remembering snippets of information but never remembering the exact details. Also can never remember where the info comes from. That said ...

I read somewhere that the 'danger' in cross drilled rotors had to do with how they were drilled. A completed rotor that has been drilled after manufacture is prone to failure where a rotor that was manufactured with the holes in them are ok?? Sounds a little hokey but maybe something to do with the heat of drilling them?

Well... I'd just like to play myth busters.

There is no danger in Zimmermann cross-drilled rotors. Just a bunch of internet bla, bla, bla. I'm not saying Sean's story about a rotor shattering at the track isn't true... it's just that there had to be some EXTREME extenuating circumstances before "anything" like that would happen (like worn rotors that should have been replaced years ago, zero pad material, stuck caliper, etc.)

Frankly, I think they're a good thing if you're going to be autocrossing or even DE events with your car. Again, those holes vent extremely hot gases that build up under the pad during hard braking.

Go take a look at the rotors on any 914 on the HSR series. These guys brake their cars harder in 20 minutes that most of us would in a lifetime. Report back.

Add some good ducting to vented and cross-drilled rotors and you will see the benefit if you're riding the brake pedal at go-fast events.

I bought 4-lug front crossdrilled Zimmermans here:

Auto Parts Warehouse

Nope, they are in Washington - Thats my brother-in law. Great guy, I let him marry my sister....

As far as my 2 cents on the rotors:

I raced street bikes for years - I have never suffered any ill effects of having tiny holes in my rotors. On my car I use the slotted cryo rotors, they work fine. I have brembo rotors on my Mercedes and they also work fine. I would tell you that IMO - whatever you put on there is going to be fine. Don't believe the hype....

You should be more concerned with pads - pads are where people often make mistakes. You must match the pad with the rotor for optimal performance and longevity. I like EBC greens with both of my setups. The main reason - they make less brake dust, which equates to less cleaning, which equals more free time. Its simple mathematics....

Thanks all,

I have ordered my Zimmerman cross drilled "sport" rotors from a trusted source and at a good price.

I am not worried about shattering these on the street....and I think they are exactly what I need...I don't know how good brembo's are but I'm sure they are good too....From what I can tell there is no evidence of anything better than Zimmerman for our applications.

Cheers,

Sean

In the past I have purchased my rotors for 964, 944 and 911 SC from Weston Motorsports.

http://westonmotorsports.com/

Good guy to work with, and an enthusiast!

Its all about mechanics. Solid rotors which are drilles are silly in application. Solid rotors are best kept solid for a maximum surface area for the brake pads, period. For drilles holes to work, the center of the rotor has to be hollow and fined for air to be charged by the fins which capture air thus preasurising the center opening between the brake surfaces and traveling out the holes in the rotor thus cooling it. If you want cooling on solid rotors, then you need to duct fresh air to them. I'm not certain of your application but going with drilles rotors would be best if you upgraded to a 911 front end and breaking system. The original breakes are said to be good for street use. The key is to slow down if there is such a thing.


Drilled rotors=15 visual HPs