Midnight Hour

Every thread I read about upgraded rotors you all tend to downplay the cross drilled rotors saying they aren't necessary since they were designed for expelling gases from a heated brake pad, which isn't a problem now since the pads are made of a different substance. Most of you also say they're more fragile and they're very prone to crack.

However, the Aston Martin Vanquish, MB SL500, Lamborghini Murcielago, all Porsche's, Saleen S7, BMW M3(maybe M5 also??), and many other top end cars have cross-drilled rotors...a lot of them being routinely track-driven types of cars.

If these are so prone to crack, why would the put them on these types of cars? I'm sure MB, BMW, Porsche, and other auto makers wouldn't want customers complaining that their rotors keep cracking. That would just be absurd. C'mon what's the deal guys?

jdhuegel1

I run them. Course I don't race... But I like them and have had no problems. Unfortunately, my hawk pads are noisy as hell though....

powermalex

I have them all the way around. No problems I hear about 50/50 about X-drilled vs sloted. You can make anything crack, break etc. if you drive hard enough!

Turbonut

iTrader: (1)

Just my thoughts. I believe if the cars mentoned are engineered, from the factory, with the cross drilled rotors there wouldn't be any problems. Of course they are a lot bigger (dia) then 7's. I would think cost would be exhorbitant for these rotors also. I don't think we can compare a factory size cross drilled/slotted 7 rotor for @ $60 to the exotics.
I personally don't think they would be a problem unless you hammer the brakes. My '89TII 158,00 miles has the original rotors, like new, and on only the 3rd set of pads. I'm thinking of putting them on 'cause I like the looks. Whats the worse that can happen? Put them on and try yhem out.

rynberg

First of all, the rotors on the exotics are not drilled, they are cast with the holes. BIG difference.

read here about Chris Regan's drilled rotor experience:

(scroll halfway down)

http://reganrotaryracing.tripod.com/gcmande.htm

Midnight Hour

Are the big brake kits such as Brembo, AP Racing, Wilwood, and the others not cast with the holes in them? I'd assume so since all of the kits cost upwards of $2k, closer to $3k.

rynberg

I don't think you can generalize that much. Some kits may and some may not. I haven't seen ANY of the good quality kits for FDs come with vented rotors to be honest......all the ones I've seen are slotted or solid.

As far as brake upgrades go, you could do what SleepR1 did and get the 99-spec Rs/Rz brakes. He said they work great on the track, even with OEM pads. They do require 17" wheels like most upgrades. Check out the stickie.

maxcooper

Drilled, stock sized rotors + track = crack.

Big drilled rotors might work fine, but drilled rotors in the stock size are very prone to cracking on the FD RX-7 IF YOU TRACK THE CAR. If you don't take the car to the track (and don't ever plan to), get whatever rotors you like the best.

I am not sure if the big brake component manufacturers drill or cast the holes in. Lots of companies make rotors, so perhaps they use different techniques. Most (all?) rotors in big brake kits are standard race rotors with custom hats for installation on the RX-7 hubs. I know that Brembo makes a Gran Turismo kit with "cross-drilled" rotors for the RX-7, but I don't know if the rotors are drilled or have cast holes. Some pads work best with solid, slotted, or drilled rotors, so you can often get a few different rotor configurations for a given size. They also differ in mass, cooling vane configuration, material quality, and hot/cold treatments.

-Max

kdxer200

Anyone seen the pierced rotors on Ebay? Drilling causes a stress point and therefore cracking, which I would think piercing would also, but I guess they dont. The people selling them said they were like 4x stronger than drilled.
Just my .02c.

Silver Ninety Three

We are running the Brembo/Ikuta crossdrilled and slotted rotors on several of our cars with no problems. This includes street and track use.

Mazderati

iTrader: (3)

Perhaps you meant that you haven't seen certain kits with cross-drilled rotors.

Kyle

Dyre

Using cross-drilled rotors isn't going to kill you on a street car, it just doesnt DO ANYTHING.
They don't help performance, they add anouther possiable falure point, and cost more money.... all for a little bLiNg BlINg...

JadedX

lol so r mine