2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

cross drilled rotors

Thread Tools
 
Search this Thread
 
Old Dec 13, 2005 | 11:44 PM
  #1  
1300ccTuner's Avatar
Thread Starter
Senior Member
Tenured Member 15 Years
 
Joined: Feb 2005
Posts: 391
Likes: 0
From: Orlando
cross drilled rotors

2 questions

where can i get some cross drilled rotors?

should i trust ebay rotors?

thanx
Reply
Old Dec 14, 2005 | 12:34 AM
  #2  
idsigloo's Avatar
Needs more Displacement.
Tenured Member 10 Years
 
Joined: Jun 2005
Posts: 1,329
Likes: 0
From: Louisville, Ky
www.rx7store.net has a whole set of brembo for like 350 or something.
Reply
Old Dec 14, 2005 | 12:54 AM
  #3  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
stay away from ebay drilled rotors.

drilled rotors must be heat tempered after drilled, most ebay sets do not temper the rotors after drilling which can cause cracking and in some extreme cases, the rotor shattering which is bad mmmkay!
Reply
Old Dec 14, 2005 | 04:19 AM
  #4  
rx7b13's Avatar
Rotary Enthusiast
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 950
Likes: 3
From: indiana
Originally Posted by Karack
stay away from ebay drilled rotors.

drilled rotors must be heat tempered after drilled, most ebay sets do not temper the rotors after drilling which can cause cracking and in some extreme cases, the rotor shattering which is bad mmmkay!

i was told that is what happens to all drilled rotors so that why im am going with powerslot slotted rotors
Reply
Old Dec 14, 2005 | 06:43 AM
  #5  
emac's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Mar 2004
Posts: 448
Likes: 0
From: MA/NJ
can you lock up your brakes? Your braking system is more than adequate. Just get quality pads and a nice set of blank rotors unless you want the "bling"
Reply
Old Dec 14, 2005 | 08:27 AM
  #6  
rotary downshift's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Sep 2005
Posts: 448
Likes: 0
From: Performance Improvements
to be compleatly honest with all of u i have been to seminars with brembo and bear and the only thing that truly improves breaking are bigger rotors .. the slots and cross drillings only bennafit in a race application so in agreeance with emac i say get good pads and a decent blank rotor .... well sauve u tones of money
Reply
Old Dec 14, 2005 | 10:08 AM
  #7  
emac's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Mar 2004
Posts: 448
Likes: 0
From: MA/NJ
if you get a bigger rotor make sure you get a new proportioning valve to fit the setup too. Being FC guys i highly doubt people will be paying for big brake kits.

But then again, even big brake kits aren't necessary in 99% of applications.
Reply
Old Dec 14, 2005 | 10:11 AM
  #8  
RockLobster's Avatar
Let's get silly...
Tenured Member: 20 Years
iTrader: (7)
 
Joined: May 2004
Posts: 1,718
Likes: 10
From: Rosemount, MN
Originally Posted by emac
can you lock up your brakes? Your braking system is more than adequate. Just get quality pads and a nice set of blank rotors unless you want the "bling"

This is false, try locking up the same brake system after a few laps at Road America.

The truth in it is that a good set of pads is best money spent to improve a stock system.

But just because you can lock your brakes up in front of your driveway dosn't mean its a good system.

Last edited by RockLobster; Dec 14, 2005 at 10:25 AM.
Reply
Old Dec 14, 2005 | 10:14 AM
  #9  
Nihilanthic's Avatar
moon ******
Tenured Member 05 Years
 
Joined: May 2005
Posts: 1,308
Likes: 0
From: Jacksonville, Florida
If its a street car and you want to waste money on looks to impress a certain crowd, go ahead. Just dont ever actually be hard on your brakes or youll crack the rotors.
Reply
Old Dec 14, 2005 | 10:18 AM
  #10  
RockLobster's Avatar
Let's get silly...
Tenured Member: 20 Years
iTrader: (7)
 
Joined: May 2004
Posts: 1,718
Likes: 10
From: Rosemount, MN
Originally Posted by 1300ccTuner
2 questions

where can i get some cross drilled rotors?

should i trust ebay rotors?

thanx
Crossed drilled are to be avoided unless you are doing it for show.

I purchased one set of drilled slotted rotors off ebay a couple years ago. One was warped out of the box, i cracked 2 of the other three in less than 5 laps on the track.

When i am at the track i never see drilled rotors and those that do try to run them just end up cracking them (or shattering them).

Best rotor mod you can have done is cryogenic treatment.

I run slotted cryos, but it is debatable if slots truly help, depends on the pad you are using.

You want a good trouble free mostly street braking system?
-Cryo Rotors (www.frozenrotors.com)
-Good set of pads (I personally like porterfield carbon kevlar for street, hawk blues for track)

Track junkies all argue about pads and slots/noslots, some guys swear by just good old brembo blanks.

All seem to agree that drilled are to be avoided at all costs.

Last edited by RockLobster; Dec 14, 2005 at 10:20 AM.
Reply
Old Dec 14, 2005 | 10:20 AM
  #11  
Sideways7's Avatar
Lives on the Forum
Tenured Member: 20 Years
Liked
iTrader: (7)
 
Joined: Dec 2003
Posts: 6,598
Likes: 10
From: Temple, Texas (Central)
DO NOT get drilled rotors. The main advantage (other than looks) is better cooling and gas dispersion, which you can also get with slotted rotors. They are much easier to crack as the holes lower the structural integrity of the rotors. I have personally witnessed a 2 month old Ferrari 360 Modena crack its rotors at TWS in College Station (I was in the car when he did it) so even the top of the line ones do it. If you really want the x-drilled look, power slot has rotors that have dimples that look like x-drilled rotors.
Edit - you can also get cryo treated slotted rotors from power slot now.
Reply
Old Dec 14, 2005 | 12:02 PM
  #12  
Nihilanthic's Avatar
moon ******
Tenured Member 05 Years
 
Joined: May 2005
Posts: 1,308
Likes: 0
From: Jacksonville, Florida
Has anyone ever studied the real effective difference in surface area for heat radiation with slots or holes before?

With slots, you gain a little surface area but because the slot is basically a concave gouge, a lot of that surface area is just facing the rest of the gouge. But well, I dont know for sure. I do know that it would help (when spinning) to allow any outgassing to float out of the rotor, and it probably doesnt exactly hurt in the rain.

With holes, though, all the increase in surface area is on the inside of the rotor, and you get stress risers from the holes themselves. The only way it could help I can conceive of is if you have vented rotors and there are vanes on the inside of the rotor moving air, and it either sucks or blows air through those said holes.

Regardless, ducting and simply having properly sized rotors would do more good IMO than drilling or slotting. Not that I've ever seen an indication slots or dimples are a bad thing, of course, and Ive seen anecdotal evidence its useful.
Reply
Old Dec 14, 2005 | 12:10 PM
  #13  
RX-Heven's Avatar
I'll blow it up real good
Tenured Member 15 Years
iTrader: (1)
 
Joined: May 2001
Posts: 2,390
Likes: 2
From: San Francisco, CA
outgassing...lol
Reply
Old Dec 14, 2005 | 12:25 PM
  #14  
emac's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Mar 2004
Posts: 448
Likes: 0
From: MA/NJ
Originally Posted by RockLobster
This is false, try locking up the same brake system after a few laps at Road America.

The truth in it is that a good set of pads is best money spent to improve a stock system.

But just because you can lock your brakes up in front of your driveway dosn't mean its a good system.
yea, how many people go to a road course enough to warrant such an expensive upgrade? That's why I said most people don't need it.
Reply
Old Dec 14, 2005 | 02:09 PM
  #15  
matts86fc3s's Avatar
southern style
Tenured Member 05 Years
 
Joined: Dec 2005
Posts: 436
Likes: 0
From: warner robins, georgia
hey ive got ebay cross drilled/slotted rotors... work great. no probs
Reply
Old Dec 14, 2005 | 02:18 PM
  #16  
MattB's Avatar
MattB
Tenured Member 05 Years
 
Joined: Apr 2005
Posts: 1,124
Likes: 0
From: Haverhill, MA
i havent had any problem with my slotted crossdrilled rotors...but i have only done street driving so i havent really heated them up as much as i will at the track in the spring
Reply
Old Dec 14, 2005 | 02:35 PM
  #17  
rx7b13's Avatar
Rotary Enthusiast
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 950
Likes: 3
From: indiana
when i was out at autox i ran blank rotors and i couldnt slow down very well after the second run.
Reply
Old Dec 14, 2005 | 02:50 PM
  #18  
emac's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Mar 2004
Posts: 448
Likes: 0
From: MA/NJ
4 pot calipers also help
Reply
Old Dec 14, 2005 | 03:10 PM
  #19  
rx7b13's Avatar
Rotary Enthusiast
Tenured Member 15 Years
 
Joined: Jun 2004
Posts: 950
Likes: 3
From: indiana
thats what i am running. i have an 88 gtu
Reply
Old Dec 14, 2005 | 03:25 PM
  #20  
Mordachai's Avatar
_
Tenured Member 15 Years
 
Joined: Feb 2004
Posts: 634
Likes: 0
From: South Florida WPB
EBC brake pads man,
Best $65 I've spent on the car so far.......
Reply
Old Dec 14, 2005 | 05:34 PM
  #21  
ilike2eatricers's Avatar
I R SAD PANDA W/O BAW
 
Joined: Nov 2002
Posts: 6,061
Likes: 1
From: bay area
Originally Posted by Nihilanthic
Has anyone ever studied the real effective difference in surface area for heat radiation with slots or holes before?

With slots, you gain a little surface area but because the slot is basically a concave gouge, a lot of that surface area is just facing the rest of the gouge. But well, I dont know for sure. I do know that it would help (when spinning) to allow any outgassing to float out of the rotor, and it probably doesnt exactly hurt in the rain.

With holes, though, all the increase in surface area is on the inside of the rotor, and you get stress risers from the holes themselves. The only way it could help I can conceive of is if you have vented rotors and there are vanes on the inside of the rotor moving air, and it either sucks or blows air through those said holes.

Regardless, ducting and simply having properly sized rotors would do more good IMO than drilling or slotting. Not that I've ever seen an indication slots or dimples are a bad thing, of course, and Ive seen anecdotal evidence its useful.
1) How many modern brake pads release gas???
2) You argue that you gain surface area but what about the loss in actual mass to absorb and dissipate heat.
Reply
Old Dec 14, 2005 | 06:37 PM
  #22  
Mordachai's Avatar
_
Tenured Member 15 Years
 
Joined: Feb 2004
Posts: 634
Likes: 0
From: South Florida WPB
I'm pretty sure almost ALL brake pads have a little slot in them, designed to help outgas.....

I know for heatsinks, that better surface area(with airflow) increases cooling. I think that mass has less to do with cooling than surface area. (IE big think chunky things stay hot longer)

there are set ups that bring cool air and force it over the rotor through fancy flexible ducting.
I've seen at least 1 FD with a set up like this.....
Reply
Old Dec 14, 2005 | 07:26 PM
  #23  
RX-Heven's Avatar
I'll blow it up real good
Tenured Member 15 Years
iTrader: (1)
 
Joined: May 2001
Posts: 2,390
Likes: 2
From: San Francisco, CA
Originally Posted by Mordachai
I'm pretty sure almost ALL brake pads have a little slot in them, designed to help outgas.....
No, they don't.
No, it does not.

Do you know why the sidewalk and other slabs of concrete have control joints? Look into it if not.

In addition to controlling cracking and deterioration, the gap aids in shedding worn away material to give the trailing section of the pad a clean surface to mate against.

Also, with longer pad designs, there maybe several gaps. The goal is to have the pad sections square.

Even bicycle brakes have gaps in them. Don't try and tell me they have outgassing problems.

Outgassing....LOL

Last edited by RX-Heven; Dec 14, 2005 at 07:33 PM.
Reply
Old Dec 14, 2005 | 07:47 PM
  #24  
spot_skater's Avatar
The Cause of Death
Tenured Member 10 Years
 
Joined: Mar 2004
Posts: 2,202
Likes: 2
From: New York
I've been running cross drilled and slotted rotors (fronts, blank rears) on my 88 base for almost a year now. The car hasn't seen track time or autox time yet, but they have held up fine for me. I have done some HARD stops/slow downs from 100+ to about 40 and they've held up just fine. No cracking or anything. I'm also running AXXIS ceramic pads. All rotors and pads were replaced at the same time, bedded in properly. Pity I'm still running single piston calipers though. Maybe after these rotors are out of spec I'll upgrade to the 4 piston...

In my opinion, if your car won't be seeing track time, cross drilled and slotted rotors are fine. NORMAL street driving and the occasional race shouldn't present a problem. After reading horror stories of these types of rotors "exploding" and cracking from track use, I'd say stay away from them. That's just if you plan on tracking the car often though.

As far as I'm concerned, with my driving style (occasional racing and normal driving) the rotors are holding up just fine. I haven't experienced brake fade either, even after harsh stops like I mentioned above.

Do what you want though. I'd say they are just for show. If you're serious about bringing your rex to the track, stick with blanks.

James
Reply
Old Dec 14, 2005 | 08:16 PM
  #25  
Nihilanthic's Avatar
moon ******
Tenured Member 05 Years
 
Joined: May 2005
Posts: 1,308
Likes: 0
From: Jacksonville, Florida
Originally Posted by ilike2eatricers
1) How many modern brake pads release gas???
2) You argue that you gain surface area but what about the loss in actual mass to absorb and dissipate heat.
1. all do to SOME degree.

2. I was asking a question! The loss of mass is negligeable, and at any rate I doubt it would lose so much mass it would acutally effect anything signifigantly.
Reply



All times are GMT -5. The time now is 02:45 AM.