Zimmermann Cross Drilled Rotors

[Robbie325i]

Been running Zimmerman X-Drilled front and rear for 3 years. No cracks. Includes two track days, lots of hard driving, and half a dozen 70-0 test fade sessions.

Rotors are wear parts, when they're worn they will crack, this doesn't mean they are defective.

Don't ask if they crack, ask how long they last before they crack, so far these have lasted as long as the OE.

The bad repuation comes from people machining the holes after they've been heat treated, which causes unrelieved stress concentrations. Not a problem if you buy factory drilled rotors.

The last Porsche I saw had drilled rotors, who do you think makes those? Brembo and Zimmerman, I think they know what they're doing.

[parkerbink]

Actually I didn't ask if they crack, I asked for opinions & I have gotten a huge amount of great info. Thanks!

[MattM20]

i use ate powerdiscs and ebc greens, and theyre a great combo. ive done two track days (one wet, one dry) in the 9months that ive had them and they have performed and held up extremely well.

[mspiegle]

i personally like to learn the hard way.

give them a try and see if you like them. zimmerman has a pretty decent reputation and i'm sure their rotors are fine.

as far as the drilling, you want rotors that have the holes casted in - not drilled. I believe zimmerman has their holes casted in - but someone correct me if i'm wrong.

[Mike 91 318ic]

As I said before use oem, there isn't any advantage going after market on brakes for a E30.

M

[Bryson]

Been running Zimmerman X-Drilled front and rear for 3 years. No cracks. Includes two track days, lots of hard driving, and half a dozen 70-0 test fade sessions.

Rotors are wear parts, when they're worn they will crack, this doesn't mean they are defective.

Don't ask if they crack, ask how long they last before they crack, so far these have lasted as long as the OE.

less than a year

edit: for the record, zimmermans are drilled.. at least the ones we're talking about
others would be referred to as 'cross-cast' rotors

[Bokes]

As I said before use oem, there isn't any advantage going after market on brakes for a E30.

M

unless you are doing lots of track days and auto-x's. but for daily, mike is right, no need for aftermarket.

[M-technik-3]

Brembo's are cross cast correct? I have heard rumur that there are two differant Brembo's floating around out there.

[mph]

I have a set of the actual cross drilled Brembo sport rotors. They are drilled when they ship. I'm not 100% sure if they are drilled or cast, but I can find out.

I have them on my 352ic and have had no problems thus far. I drove the car last winter in the Ohio weather and I have yet to have a problem. I've had mine for a little over a year now.

I would recommend you don't buy the Brembo cross drilled rotors on ebay, same goes for any cross drilled rotor. Most of the sellers drill the rotors themselves. Brembo and Zimmerman have engineers that tested them.

In regards to whether or not they are better than stock rotors, I would say they are. My car seems to stop a lot faster. Only problem is you wear the pads much faster.

Brembos are nice because they coat the rotors so they wont rust anywhere but the braking surface.

[Nick325is]

The powerslots are something like 220 dollars for the fronts.


Nick

[mph]

The Brembo cross drilled sports are $300-400 a pair.