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914World.com _ 914World Garage _ What Rotors to use

Posted by: 914_teener Oct 31 2009, 09:20 PM

I had a couple of rotors turned today. This is the second set of rotors I have been through.....stock rotors.

Maybe this has been covered in previous threads....I couldn't find any so excuse me if it has. In every ones experience what are the best rotors to use. It seems like the stock rotor steel is too soft and I am on my third set. I like driving the car in the local mountain roads on the weekends but after a while the rotors seems to ridge ( particulary the front) prematurely. Sorry no sexy pictures but it just seems like the stock ones go bad to soon.

Rob

Posted by: sean_v8_914 Oct 31 2009, 10:20 PM

something is wrong here. I flog 914s without mercy. been doing it onteh track and street ...never seen that to be true. what else is going on in that system

Posted by: john rogers Oct 31 2009, 10:25 PM

If you have stock brakes then stock rotors are about the only choice. Pads can make a big difference though and throughout my later car life I have used the Metal Master or Axxis (same company) semi metalic pads and they gave even wear, low dust no rotor problems, etc. The front end is the same as an old VW 411 if I remember correctly and there used to be some hot rod stuff made for them but not any longer.

The next step is to either convert to 911 5 lug or get Brad Robert's alloy hubs that use the vented rotors and M calipers and keep the 4 bolt wheels.

Posted by: 914_teener Oct 31 2009, 10:38 PM

Ok.... thanks for the feedback.

Wonder if it is because they are used rotor's . Most of the driving is mountain driving. I am on the same set of OEM recomemded pads nothing special. I have been through two sets of stock rotors from the PO. The first set was worn past .354 so I turned a second set. I know the AX guys rip these but I am wondering if the weight transfer is different for what I drive.

The guy that turned the last set today said that the steel for teeners and some Mercedes is too soft to turn and doesn't last too long and they rarely get turned twice.

BS or what? Thanks

Posted by: sean_v8_914 Oct 31 2009, 10:41 PM

OK so same pads with 3 sets of rotors...is that right? no, it would be wrong.

Posted by: davep Oct 31 2009, 10:49 PM

It may depend on the brand of rotor to some degree. I have always used Zimmermann. They are cast iron, not steel per se. The stock rotors do not have much wear allowed from original thickness to throw away. To improve on the wear characteristics you could have them cryogenically treated.

Posted by: Cap'n Krusty Oct 31 2009, 11:18 PM

Right. They're cast iron, not steel. With the prohibition on asbestos in brake pads, pads are much harder and more abrasive than they were when our cars were designed. Gone are the days of effectively "lifetime" rotors. Having been in the biz for 36 years, I can tell you honestly that there are 911s and 914s out there that are running the original rotors, and as long as my rapidly shrinking stock of NOS 1970s pads runs out (pretty soon now) they'll join the ranks of a pads and rotors brake job, just like all the newer cars. We don't even TRY to surface rotors any more, as they're always so close to the minimum it's not worth the time. Rotors are cheaper now, too. Live with it, just like everybody else.

The Cap'n

Posted by: 914_teener Oct 31 2009, 11:20 PM

Sean..

Not exactly.... when I bought the car the pads were new and the rotors were out of spec, past .354. I had a spare set so had those turned. Drove on them weekend driving...mountain roads...fun, and about 5,000 miles later, those were past spec.

So I quess that means two stock rotors to one set of pads.

I am doing the front end this Winter and am pondering if the "frozen" or cyrogenically treated as our friend from the Great North suggests is the better bet? Or is there something in my set up that is potentialy wrong? Maybe it is just my foot

Anyway, thanks for the feedback.

Posted by: 914_teener Oct 31 2009, 11:23 PM

Ah...thanks Capn for chiming in...that is what I am hearing.

Ok.. think I will go with the modern rotor alloy.

Rob

Posted by: jt914-6 Nov 1 2009, 07:32 AM

Although I'm using Carrera slotted rotors with C2 calipers on a five lug set up and not a stock 4 system I had my rotors "frozen" when they were new. I built the car for street/track use and wanted a good brake system. Since finishing the car in March I don't have enough miles yet to tell about wear. I do have two DE's with them using race pads and several thousand street miles using street pads. At one time I used drilled rotors for street/track usage, but started to get heat cracks in them. Went with slotted this time and I think it was a good choice. Here is where I had mine done...... http://www.diversifiedcryogenics.com/index-2.html

Posted by: 914Sixer Nov 1 2009, 08:34 AM

Make sure you use the Zimmerman rotors. For a while there were rotors made in South American that were crap! They were out of round and out of balance. The original Textar pads show up from time to time on Ebay. Keep the parts original German for best results.