The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:

Go Back   The Subaru SVX World Network > SVX Main Forums > Technical Q & A

Reply
 
Thread Tools Display Modes
  #1  
Old 03-08-2007, 06:45 AM
JaySVX's Avatar
JaySVX JaySVX is offline
Bad decisions effect everybody
 
Join Date: Mar 2007
Location: Collegeville, PA
Posts: 1,902
Send a message via AIM to JaySVX Send a message via Yahoo to JaySVX
Drilled/Slotted Rotors

How important is it to have drilled and slotted rotors on the SVX? Are the OEM rotors like that, or are they normal? Whiel it's nice to have additional cooling on the breaks, if they're not necessary, i'm not a race car driver, and an extra 200+$ for them doesn't seem worth it. Thanks.
Reply With Quote
  #2  
Old 03-08-2007, 06:57 AM
Mr. Pockets's Avatar
Mr. Pockets Mr. Pockets is offline
Moderator
 
Join Date: Apr 2001
Location: Champaign, IL
Posts: 6,916
Send a message via ICQ to Mr. Pockets
Registered SVX
It isn't, and the people who buy them are not, for the most part, race car drivers either. I mean no disrespect towards the people on this site, but the vast majority buy slotted and drilled rotors because they look cool, not because they've been proven to actually work better on the car.

Do they work 'better?' The best any of us could honestly say is maybe. As far as I know, nobody's actually tested how slots and/or holes affect stopping distance, brake temperature and longevity.

I intend to buy new brakes for my SVX very shortly. I will either have them slotted or leave them solid. Honestly, I'm waiting on my own unscientific study to decide. My friend and I put slotted rotors on his car, which we will both be autocrossing this year, and I'm waiting to see how that affects the car.
__________________


2005 RX-8 Grand Touring
2005 Outback
2002 Mercedes-Benz E320 wagon

END OF LINE
Reply With Quote
  #3  
Old 03-08-2007, 07:25 AM
Michael Blue's Avatar
Michael Blue Michael Blue is offline
Sold. :'-(
 
Join Date: Feb 2004
Location: Morton, IL, USA
Posts: 446
I put the eBay drilled/slotted rotors on my car, since because with the Axxis pads and s/s lines, they were still cheaper than AutoZone cheapies, and also because they were cad plated, so they wouldn't rust, etc.
(Just type "SVX" into an eBay search, they're all over the first page currently).

Drilled and slotted rotors do help expel gasses from building up between the pad and rotor, and help keep the pads from aquaplaning on the rotors (a problem in some cars). Honestly on the street the better braking I notice is simply from having newer equipment and better pads, I don't attribute any of it to the rotors themselves in my case.

Now, but actual "big" brake kits, etc, when used on the track, drilling and/or slotting will make a difference in heat dissipation, which will aid in braking distances as well as brake longevity.

One last note: Drilled rotors crack, and slotted rotors are very tough on pads. There are a handfull of rotors out there where the holes are cast in, instead of drilled in after the fact, and this helps, but they're very expensive. Porsche OE rotors and Slot*It are the only ones I'm aware of. I don't know whether rotors which are "dimpled" instead of drilled are as effective at dissipating heat or water, or at crack resistance.

Good luck!
__________________
'92 Pearl White LS-L Touring SOLD
4.44 Swap, trans cooler, trans filter, trans temp gauge
Color-matched rear body and spoiler, X-drilled and slotted rotors, Axis pads, s/s lines
Raxles front axles
Reply With Quote
  #4  
Old 03-08-2007, 08:03 AM
ItsPeteReally ItsPeteReally is offline
Registered User
 
Join Date: Feb 2006
Location: Ipswich, Suffolk
Posts: 143
Quote:
Originally Posted by JaySVX
How important is it to have drilled and slotted rotors on the SVX? Are the OEM rotors like that, or are they normal? Whiel it's nice to have additional cooling on the breaks, if they're not necessary, i'm not a race car driver, and an extra 200+$ for them doesn't seem worth it. Thanks.
I'll let you make up your own mind. Here is the URL of the technical data page from a company called Power Stop Extreme Performance http://www.autospecialty.com/html/co...to_thrive.html

They would certainly want to try and sell you some drilled and slotted rotors, wouldn't they?

Lets take a look at the temperature graph


Even though this graph doesn't show you how hard the brakes were applied, from what speed, or what the time interval was between each brake application was, one thing is immediately apparent, on the first stop, drilled rotors make no difference at all.

Subsequent stops show a small but growing temperature difference, we know that there must be some shortish time difference between the two stops, as a longer time interval would have allowed the solid rotors to have cooled down. By the time we get to the 15th stop there is a 200 degree temperature difference. How significant is that?

Well lets look at the next graph


The graph shows that there is a reduction in coefficient of friction of about 20% or so, whatever pads you have fitted, so there is some minor 'fade' but not enough to have you running out of leg muscle.

The other graphs are of little interest, and tell you little worth knowing - one of them even has the axes mislabelled.

Bearing in mind that the SVX already has ventilated discs at the front, and at the rear too, outside the USA, how much benefit do you think you are going to get from aftermarket rotors.

Make up your own mind.
__________________
I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be.
Sir William Thomson
Reply With Quote
  #5  
Old 03-08-2007, 08:29 AM
JaySVX's Avatar
JaySVX JaySVX is offline
Bad decisions effect everybody
 
Join Date: Mar 2007
Location: Collegeville, PA
Posts: 1,902
Send a message via AIM to JaySVX Send a message via Yahoo to JaySVX
Thanks for the input. I know the general principal about them, but short of auto-x or something similar, i can't see them being a big deal. I saw the package on ebay about the rotors, pads, and lines. it's 160 for 4 new rotors and all new pads, which i think will be good for the time being. Want to get some other stuff done on hte car before i do that. Anyone have any experience with larger than calipers on the car? For the mx-6/probe you could put 3000gt calipars and rotors on if you boared out the screw holes and just used other bolts, and there was a huge difference in stopping distance and over-all performance. Thanks though for the input. I think i'll put drilled/slotted on the back burner for the time being.
Reply With Quote
  #6  
Old 03-08-2007, 10:10 AM
Michael Blue's Avatar
Michael Blue Michael Blue is offline
Sold. :'-(
 
Join Date: Feb 2004
Location: Morton, IL, USA
Posts: 446
Larger calipers will make a big difference, as will more aggressive pads.

I've been considering having a local race shop (ALMS supplier) develop a 4-piston kit using the OE rotor size.
__________________
'92 Pearl White LS-L Touring SOLD
4.44 Swap, trans cooler, trans filter, trans temp gauge
Color-matched rear body and spoiler, X-drilled and slotted rotors, Axis pads, s/s lines
Raxles front axles
Reply With Quote
  #7  
Old 03-08-2007, 12:16 PM
dmnknightomega6 dmnknightomega6 is offline
Registered User
 
Join Date: Nov 2005
Location: Oakbrook Terrace, Illinois
Posts: 191
For my 2 pennies, The SS lines have better response. That would be the best for in response.
Reply With Quote
  #8  
Old 03-08-2007, 12:54 PM
SVX_MY_BABY's Avatar
SVX_MY_BABY SVX_MY_BABY is offline
Posting since Dec.'98
Subaru Silver Contributor
 
Join Date: Jun 2002
Location: HALIFAX Nova Scotia
Posts: 1,473
Registered SVX
I put ART (Applied Rotor Technology) Cryogenic treated slotted rotors on quite a while ago along with metallic pads. They were less than OEM and have lasted a lot longer than OEM. They used to offer a discount to the group. Pretty sure they still do. The Cryogenic treatment is a whole story unto itself, but I feel it's worth while.. Pics in my locker.
http://www.subaru-svx.net/photos/fil...BABY/4388.html

Last edited by SVX_MY_BABY; 03-08-2007 at 01:31 PM.
Reply With Quote
  #9  
Old 03-08-2007, 01:25 PM
dcarrb dcarrb is offline
Registered User
 
Join Date: Nov 2003
Location: none
Posts: 3,430
The brakes on my teal SVX have required no attention in 40,000+ miles of routine work, with lots of very curvy roads and a few panic stops thrown in. You really don't need any sort of "performance" brake components for anything but sustained aggressive driving.

dcb
Reply With Quote
  #10  
Old 03-08-2007, 04:56 PM
ensteele's Avatar
ensteele ensteele is offline
Betcha can't buy just one!
Alcyone Gold Contributor
 
Join Date: Jan 2002
Location: Burlington, WA
Posts: 19,552
Send a message via ICQ to ensteele Send a message via Yahoo to ensteele Send a message via Skype™ to ensteele
Registered SVX Classic SVX
If you want to improve your braking performance, the one thing that I would do without question is put a set of SS brake lines on. That did more for my brakes than anyother thing I have done.
__________________
.
Earl .... ... .... ><SVX(*>

Subaru Ambassador

[COLOR=”silver”]1992 Tri Color L[/COLOR] ~45K (06/91) #2430
1992 Dark Teal LS-L ~184K (05/91) #0739
1992 Claret LS-L ~196K (05/91) #0831
1992 Pearl LS-L ~103K (06/91) #1680
1992 Pearl LS-L ~151K (06/91) #2229
1992 Dark Teal LS ~150K (07/91) #3098 (parts car)
1992 White LS-L ~139K (08/92) #6913
1993 25th AE ~98K (02/93) #164
1993 25th AE ~58K (02/93) #176
1993 25th AE ~107K (02/93) #215
1993 25th AE ~162K (02/93) #223
1994 Laguna Blue Pearl LSi ~124K (1/94) #2408
1994 Laguna Blue Pearl LSi ~144K (10/93) #1484
1994 Laguna Blue Pearl LSi ~68K (10/93) #1525
1994 Barcelona Red LSi ~46K (02/94) #2624
1994 Pearl LSi ~41K (12/93) #1961
1995 Bordeaux Pearl LSi ~70K (02/95) #855
1996 Polo Green LSi ~95K (03/96) #872
1997 Bordeaux Pearl LSi ~55K (08/96) #097
2003 Brilliant Red LS1 Convertible ~29K (04/03) #8951
1999 Magnetic Red LS1 Coupe ~33K (04/99) #6420

My Email | Old Locker | New Locker | Picture of 15 of the 19
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 12:47 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122