Looking at upgrading my brakes in the far distant future and I was wondering if anyone has ever heard of cross drilled rotos cracking? I've heard numerous people say that they are prone to shattering but if this is the case then why do people buy them?

Your comments are appreciated

Robert

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1987 IROC-Z Auto (LB9)
Black/grey interior with the stance of a streetfighter
I like to think of her as Arnold Schwartzeneger in a dinner suit

Mods
Custom exhaust. 4 Inch pipe from the headders all the way back to a single muffler at the rear. No Cat. K&Ns, AFPR and Air foil.

Future mods:
Cam change
New torque converter
New heads (maybe corvette L98)
Strut brace
Sub frame connectors
Ram Air

Current G-Tech times
0-60mph 6.26 seconds
1/4 14.74@100.2mph

 

I've heard of it. Why do people buy them?

1. Because they look cool.
2. Because if they're good for the track they must be good for the street.

[This message has been edited by Apeiron (edited April 09, 2001).]

 

You could use a slotted rotor...

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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

 

You should use a GOOD QUALITY rotor... whether it's slotted or cross drilled.


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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

check with the pad manufacturer and see if its even necessary to drill the rotors (unless weigth is your deal). We ran rotors on the TransAm cars (SCCA TransAm series) that weren't even slotted, per the pad manufacturers advice. (PFC pads, alcon rotors).
The fact that a rotor is drilled should have no affect on whether it will crack or not (when they get hot, they get hot).
I'm not sure what the advantages are and how the racing stuff differs from street applications, so I'll shut up now


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Clem
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1983 Z28 with LG4, 5 speed, and (unfortunately) T-tops
1983 Z28, NO T-tops, (unfortunately) Auto Transmission---FOR SALE---
Looking for a V8, preferably 4 or 5 speed Camaro with NO T-tops (wanna trade?)

[This message has been edited by clemsparks (edited April 09, 2001).]

 

I have heard that the process that the holes are made effects the life of a drilled rotor. If the rotor was cast with the hoels in it, it will live longer than if the holes were drilled after the disc was made. Sounds like a valid reason to me. I guess the drilling could make small microscopic cracks in the metal around the hole, and eventually spread.

 

Cross drilling/slotting reduces brake swept area. 99 44/100 of all race cars use full face rotors

 

Look here: http://www.ws6.com/cryo.htm

Doug

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'91 Z28 - 50,000 miles. All power options leather. 350 TPI:
K&N; Fastchip; Airfoil; Custom 'Ram-Air'; SLP Headers; Slp Runners; Borla Catback 50% open; Dual factory Cats; Poweraid TB spacer; March underdrive pulleys; Accel Extreme 9000 wires, Accel coil; Hypertech rotor & cap; NGK platinum plugs; manual fan switch; TB coolant bypass; Pirelli P7000 Z245/50/R16 all season tires; Energy suspention motor mounts; smog pump delete.
S Cobra Radar Detector; Z28 SS Floormats

 

I have had Powerstop cross-drilled rotors since March 2000 (a little over a year now) with just under 20,000 miles of occasional spirited driving on them, and they're not cracked or in any way deficient.

Just one experience. Take it how you will.

 

Cross-drilling the rotors was mainly to give the gases generated by heating the pads (stepping on the brake....) someplace to go. the problem you run into is on the inside of the swept area (between the disc faces) the drilling process leaves burrs. This is a good place for cracks to start. Most pads manufactured today use compounds that significantly reduce out-gassing of the pads, so cross-drilling is not really necessary.