Surprising position on brake rotors... - ZR-1 Net Registry Forums

Paul Workman · 01-13-2010

A friend of mine has a GTO dedicated to track work, and we got to jawing about racing - would love to put the Z on a track sometime, but I digress... I am due for a set of pads at the least, and I like the "drilled and slotted" (rotors) look, so I asked him for a recommendation...

"I wouldn't!!" was his reply. To boil down a couple beers and BS, he uses good ol' solid cast iron rotors. Now, calipers and pads are a different story all together, but the issue w/ the fancy rotors most of us mortal men can afford to buy is cracking...especially if they are drilled! (The slots are not a problem and work as advertised...but no holes (for him) apparently.) He pointed out how often the drilled rotor people talk about warranties against cracking which is an admission of a problem with the things, not to mention personal experience.

Anywayz, I perhaps I have been a victim of the hype surrounding drilled and slotted rotors (I still think they look great!), but I'd be curious to know what Jeff Flint et al has to say about brakes from the perspective of a seasoned track runner!? Is it "just a matter of money" to get good (read: will not crack) drilled and slotted rotors??

Speaking of rotors, this is a good read, and I can attest to the recommendations for avoiding hard spots (aka "warping"). FYI.

P.

tomtom72 · 01-13-2010

I've hear the same thing about the drilled rotors.....N/G for anything but "bling" factor.

I can't remember where I read it but I came across some info yrs ago that said it depends upon when the holes were made & how they were made that is related to the resisting of cracking on a cast rotor.....it may have been in a car mag a long time ago? I just can't remember...senility I guess

vettn71 · 01-13-2010

from what I understand the holes are for "bling" only. Some rotors which are cryogenically treated are supposed to be crack-resistant, but if you look at professional racers they are using solid rotors.

Jim

VetteMed · 01-13-2010

From what I've read, cross-drilling was started years ago when the older pad compounds would produce gas upon use, and that gas would effectively float the pad away from the rotor surface. Nowadays, out-gassing isn't much of an issue, and so the cross-drilling has become unnecessary from a function point of view.

01-13-2010

Paul, I run cross drilled rotors on my Z at the track, and that set of rotors have been on the car for roughly about 6 years with heavy track use. Granted these are Porsche rotors that have the holes CAST, not drilled as many places do. The cost of replacements is kind of high.

On my race car, I am using standard blanks for a C5. The car is a lot lighter, and I don't want to spend an ungodly amount on a brake set up. Currently the C5 set up has been working great.

carter200 · 01-13-2010

Quote:

Originally Posted by VetteMed

Nowadays, out-gassing isn't much of an issue, and so the cross-drilling has become unnecessary from a function point of view.

I out-gas butt that is a whole nuther issue..................

VetteMed · 01-13-2010

Quote:

Originally Posted by carter200

I out-gas butt that is a whole nuther issue..................

And that's where you really have to watch out for cracks!!

Bell Curve · 01-13-2010

32valvZ · 01-13-2010

I would agree with your buddy. I had a set of D&S rotors on my old 94 convertible 6 speed. They looked great. But, I like to do some aggressive mountain driving here where I live and even doing just that I started seeing tiny hairline cracks near the drilled holes. I think unless you jump into some Brembos or some other real high dollar rotors, the result might be the same.

xlr8nflorida · 01-13-2010

I have 4 Baer Eradispeeds, they are 3 years old and still look new.

BaerÂ´s rotors are CAST with cross-drilling in mind, from the material specified, to curved vanes, behind which the holes are placed to minimize potential crack migration.

If it was a car designated just for racing, I'd say slotted only. If its a combo car then drilled slotted is fine.

Baer Rotors are Guaranteed for 3 years against warping and cracking. I don't worry about it!

I swear some of the ones on ebay, I think they put the holes in with a standard drill.

You get what you pay for. Good Slotted/drilled rotors will cost you $1,000+

01-13-2010	#1
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Surprising position on brake rotors... A friend of mine has a GTO dedicated to track work, and we got to jawing about racing - would love to put the Z on a track sometime, but I digress... I am due for a set of pads at the least, and I like the "drilled and slotted" (rotors) look, so I asked him for a recommendation... *"I wouldn't!!"* was his reply. To boil down a couple beers and BS, he uses good ol' solid cast iron rotors. Now, calipers and pads are a different story all together, but the issue w/ the fancy rotors most of us mortal men can afford to buy is cracking...especially if they are drilled! (The slots are not a problem and work as advertised...but no holes (for him) apparently.) He pointed out how often the drilled rotor people talk about warranties against cracking which is an admission of a problem with the things, not to mention personal experience. Anywayz, I perhaps I have been a victim of the hype surrounding drilled and slotted rotors (I still think they look great!), but I'd be curious to know what Jeff Flint et al has to say about brakes from the perspective of a seasoned track runner!? Is it "just a matter of money" to get good (read: will not crack) drilled and slotted rotors?? Speaking of rotors, this is a good read, and I can attest to the recommendations for avoiding hard spots (aka "warping"). FYI. P. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry Last edited by Paul Workman; 01-13-2010 at 06:47 AM. Reason: adding a link

01-13-2010	#2
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Surprising position on brake rotors... I've hear the same thing about the drilled rotors.....N/G for anything but "bling" factor. I can't remember where I read it but I came across some info yrs ago that said it depends upon when the holes were made & how they were made that is related to the resisting of cracking on a cast rotor.....it may have been in a car mag a long time ago? I just can't remember...senility I guess __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

01-13-2010	#3
vettn71 Join Date: Oct 2008 Location: Colleyville, TX Posts: 272	Re: Surprising position on brake rotors... from what I understand the holes are for "bling" only. Some rotors which are cryogenically treated are supposed to be crack-resistant, but if you look at professional racers they are using solid rotors. Jim Last edited by vettn71; 01-13-2010 at 08:51 AM.

01-13-2010	#4
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,828	Re: Surprising position on brake rotors... From what I've read, cross-drilling was started years ago when the older pad compounds would produce gas upon use, and that gas would effectively float the pad away from the rotor surface. Nowadays, out-gassing isn't much of an issue, and so the cross-drilling has become unnecessary from a function point of view.

01-13-2010	#5
Jeffvette Guest Posts: n/a	Re: Surprising position on brake rotors... Paul, I run cross drilled rotors on my Z at the track, and that set of rotors have been on the car for roughly about 6 years with heavy track use. Granted these are Porsche rotors that have the holes CAST, not drilled as many places do. The cost of replacements is kind of high. On my race car, I am using standard blanks for a C5. The car is a lot lighter, and I don't want to spend an ungodly amount on a brake set up. Currently the C5 set up has been working great.

01-13-2010	#8
Bell Curve Join Date: Aug 2005 Location: Pineridge Posts: 341	Re: Surprising position on brake rotors...

01-13-2010	#9
32valvZ Join Date: Nov 2007 Location: Sunshine State Posts: 1,071	Re: Surprising position on brake rotors... I would agree with your buddy. I had a set of D&S rotors on my old 94 convertible 6 speed. They looked great. But, I like to do some aggressive mountain driving here where I live and even doing just that I started seeing tiny hairline cracks near the drilled holes. I think unless you jump into some Brembos or some other real high dollar rotors, the result might be the same. __________________ [B]1990 #2815[/B] [COLOR="Red"][B]Red/Red[/B][/COLOR] Ported Plenum & IH (by Pete) Haibeck Chip Rebuilt FPR (by Phil) FIC Injectors Watson LT Headers 3" Stainless Works exhaust Lingenfelter Open Air Lid Bill B Built Transmission Shifter & C Beam Plates [FONT=Impact][COLOR=red]1992 [COLOR=black]#[/COLOR] 091[/COLOR][/FONT] [FONT=Impact][COLOR=#ff0000]Red/[COLOR=silver]Gray[/COLOR][/COLOR][/FONT] [B]SOLD[/B]

01-13-2010	#10
xlr8nflorida Join Date: May 2008 Location: USA Posts: 1,096	Re: Surprising position on brake rotors... I have 4 Baer Eradispeeds, they are 3 years old and still look new. BaerÂ´s rotors are CAST with cross-drilling in mind, from the material specified, to curved vanes, behind which the holes are placed to minimize potential crack migration. If it was a car designated just for racing, I'd say slotted only. If its a combo car then drilled slotted is fine. Baer Rotors are Guaranteed for 3 years against warping and cracking. I don't worry about it! I swear some of the ones on ebay, I think they put the holes in with a standard drill. You get what you pay for. Good Slotted/drilled rotors will cost you $1,000+ Last edited by xlr8nflorida; 01-13-2010 at 06:35 PM.

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