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Zimmerman failures?


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Hi all,

Since I'm about to change pads, I've decided to do some other things too (notably change the rotors too - for same-size, preferably cross-drilled). I've seen that a lot of people seem to like the Zimmerman rotor upgrades, but I was wondering if anyone had actually heard of any failures using these rotors, especially the cross-drilled ones? I'm not sure how Zimmerman construct these (can't find a manufacturers website for them!!), and whether they drill or cast the holes...

Also, it seems to be "general knowledge" that some German automakers use Zimmerman for their OEM rotors - notably Porsche and BMW - but does this mean that their aftermarket rotors are built to the same OEM quality standard? Or do manufacturers only use Zimmerman for their "low end" rotors, and someone like Brembo for their high-end rotors (effectively implying that Zimmerman aren't the best quality)?

Ultimately I will be using the car for spirited AND lots of track driving, so I don't really want the rotors to end up cracking on me... I've heard that Zimmerman does heat treat their rotors for stress relief, and also chamfer/radius/countersink the holes to remove sharp edges, but this is unconfirmed (and looking at a rotor I could only tell if they were chamfered, but not if they were heat treated)!

The other concern I have is that, although I don't want to spend huge amounts on rotors, the Zimmerman cross-drilled rotors are pretty darn cheap (generally around $112/each)! So, I'm not sure if this reflects on the quality at all...

Anyway, comments/suggestions welcome! If someone has a website for them, that'd be great too!

Thanks!

Shash

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Hi all,

Since I'm about to change pads, I've decided to do some other things too (notably change the rotors too - for same-size, preferably cross-drilled). I've seen that a lot of people seem to like the Zimmerman rotor upgrades, but I was wondering if anyone had actually heard of any failures using these rotors, especially the cross-drilled ones? I'm not sure how Zimmerman construct these (can't find a manufacturers website for them!!), and whether they drill or cast the holes...

Also, it seems to be "general knowledge" that some German automakers use Zimmerman for their OEM rotors - notably Porsche and BMW - but does this mean that their aftermarket rotors are built to the same OEM quality standard? Or do manufacturers only use Zimmerman for their "low end" rotors, and someone like Brembo for their high-end rotors (effectively implying that Zimmerman aren't the best quality)?

Ultimately I will be using the car for spirited AND lots of track driving, so I don't really want the rotors to end up cracking on me... I've heard that Zimmerman does heat treat their rotors for stress relief, and also chamfer/radius/countersink the holes to remove sharp edges, but this is unconfirmed (and looking at a rotor I could only tell if they were chamfered, but not if they were heat treated)!

The other concern I have is that, although I don't want to spend huge amounts on rotors, the Zimmerman cross-drilled rotors are pretty darn cheap (generally around $112/each)! So, I'm not sure if this reflects on the quality at all...

Anyway, comments/suggestions welcome! If someone has a website for them, that'd be great too!

Thanks!

Shash

I've been using Zimmerman rotor since January. So far I have no problem and with lots of street braking..

One thing I noticed is it cools down much faster than solid rotor. Using good quality pad is also PLUS+

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Thanks Jeff... So it appears, pretty accurately, that Zimmerman are NOT the OE suppliers for Porsche anymore, and many (unscrupulous or misinformed) vendors claim that they still are so they can pedal their wares...

As for SHW, I guess we'll find out if we can get aftermarket rotors from them... Maybe in the meantime Brembo are the best source for a "quality" rotor, although a lot of people seem to be having no problems with Zimmerman - even with heavy on-track use.

Still, some good concrete statistics for Zimmerman failures (even better would be vs OE vs Brembo vs AP vs etc) would be useful...

Thanks!

Shash

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After 7 year of Boxstering and having seen messages on the boards and from vendors, claiming that Zimmermann makes the rotors, I had some doubt. Also, check out this PCA article. http://www.pca.org/tech/tech_qa_question.a...3-30B2B010D1D5}

Last year we discussed the rotor vendor issue on a German Boxster board. There is some issue and I am not sure if it has to do with their TUV approval, or Zimmermann is no longer a vendor, or Zimmermann is not the same quality, or they produce an A rotor and a B aftermarket rotor.. http://www.staunet.de/phpBB2/viewtopic.php...ighlight=#44293 You may have to register to see the German Boxster board link.

The guy on rennlist claimed they are made by the German based company SHW. I sent SHW an email 2 months ago and got no response. The rennlist poster was going to check into it, but so far no new info.

Then there are the claims the rotors are made by Brembo.

Since Porsche makes nothing, I think they are made by the lowest bidder in China. :D

http://www.autonews.com/assets/PDF/CA410515.PDF

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These people are claiming to have cross-drilled rotors for the 986 (non-S):

http://www.evoms.com/p_box%20brake%20upgrades.htm

So, who would like to bet that this supplier is "misinformed"?

OEM Grade X-Drilled Rotors: These direct replacement cross drilled rotors are manufactured by the OEM supplier to Porsche. Offers better braking power and brake cooling at a price that is less expensive than Porsche replacement rotors. Why spend $490 for a set of 4 OEM rotors when you can have better equipment for about 20% less. NOTE: Porsche upgraded the Boxster to X-drilled on the S in 2000 for the same reasons as stated above: BETTER BRAKE PERFORMANCE. Sold in pairs.

It looks like a pair of Zimmermans to me - and the price seems to support that theory...

Thanks!

Shash

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The picture in the link may not be what they are selling. Just a stock picture of a rotor.

Zimmermann does sell cross-drilled rotors for the base Boxster. Easy to find on ebay, and the picture below is from ebay for the front base Box.

Zimmermann and SHW have sites.

http://www.otto-zimmermann.de/english/page...wirueberuns.htm

http://sprimag.de/web-de.nsf/Webstart-ENG-Master?OpenPage

post-4-1147676873_thumb.jpg

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One thing to note - Porsche OEM rotors have a grey rust proof paint on the hub. Zimmerman does not. After a few weeks, you can see the rust on the zimmerman hubs through the wheel trim - a bit ugly. I heard one suggestion to paint the hubs with high temp rust paint. I haven't done this - interested if anyone else has and what brand they used and what prep they needed to do. I don't need the paint flaking off at the wrong moment.

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  • 2 weeks later...
One thing to note - Porsche OEM rotors have a grey rust proof paint on the hub. Zimmerman does not. After a few weeks, you can see the rust on the zimmerman hubs through the wheel trim - a bit ugly. I heard one suggestion to paint the hubs with high temp rust paint. I haven't done this - interested if anyone else has and what brand they used and what prep they needed to do. I don't need the paint flaking off at the wrong moment.

http://www.renntech.org/forums/index.php?act=ST&f=104&t=8861

I had to paint my zimmerman rotor with VHT high-temp paint.

Looks great now.

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