Race Car Tech Discuss anything related to road racing and auto X.

Slotted rotors = waste of money?

Old 06-05-16, 08:13 AM
  #1  
Eats, Sleeps, Dreams Rotary
Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,206
Liked 6 Times in 6 Posts
Slotted rotors = waste of money?

Are they?
Valkyrie is offline  
Old 06-05-16, 10:02 AM
  #2  
Armchair engineer
iTrader: (2)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: http://www.k2rd.com
Posts: 24,398
Likes: 0
Liked 108 Times in 98 Posts
we switched to slotted rotors, because we get contingency. only measurable difference is that you now have a wear indicator, IE when the slots are gone rotor needs to be replaced.
j9fd3s is online now  
Old 06-05-16, 08:11 PM
  #3  
Eats, Sleeps, Dreams Rotary
Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,206
Liked 6 Times in 6 Posts
Originally Posted by j9fd3s View Post
we switched to slotted rotors, because we get contingency. only measurable difference is that you now have a wear indicator, IE when the slots are gone rotor needs to be replaced.
Thanks... Still wondering if I should shell out extra for heat treated rotors.
Valkyrie is offline  
Old 06-05-16, 08:24 PM
  #4  
Fistful of steel
iTrader: (7)
 
LargeOrangeFont's Avatar
 
Join Date: Nov 2008
Location: OC, So Cal
Posts: 2,141
Liked 6 Times in 6 Posts
No they are a waste. Buy high quality blank rotors and be done. Centric premium, or even better the high carbon line work very well.
LargeOrangeFont is offline  
Old 06-06-16, 05:35 AM
  #5  
Death to Infinite Scroll
 
peejay's Avatar
 
Join Date: May 2001
Location: Cleveland, Ohio, USA
Posts: 11,652
Liked 37 Times in 34 Posts
I would think any heat treating you do would be altered/ruined after you heat cycle the rotors.

Rotors will often get hotter than normal heat treatment temperatures and the cooldown isn't anywhere near as controlled.

Now, if they were heat cycled before machining.... maybe that's a good idea? Or maybe it is cheaper to just get the rotors machined IF they warp after use on the car. If they warp from heat, they typically only do it once, machine them flat/square again and they will be good until they finally crack or wear out.
peejay is offline  
Old 06-06-16, 09:24 AM
  #6  
Long time on-looker
iTrader: (33)
 
Join Date: Oct 2005
Location: Columbus, OH
Posts: 835
Liked 16 Times in 16 Posts
the only reason to consider slotted rotors in my opinion is if they're the only offering from a reputable company. For instance on the FD in the stock size I was using powerslot rotors in the rear. Not because I thought the slots were an advantage, but because they're quality made rotors and would last longer than the parts-store versions during track abuse.

If you're considering no-name ebay slotted rotors then pass.

On the front I'm using the AP j-hook slotted rotors. I wouldn't trade them for the world, but I don't believe their value is really in the slots but more that the rotors are made from great quality iron and take a ton of abuse.
Smokey The Talon is offline  
Old 06-06-16, 03:41 PM
  #7  
Fistful of steel
iTrader: (7)
 
LargeOrangeFont's Avatar
 
Join Date: Nov 2008
Location: OC, So Cal
Posts: 2,141
Liked 6 Times in 6 Posts
Buying them before they are slotted is cheaper. Stoptech slotted or drilled rotors start out life as Centric Premium blank rotors.

The rotors on the back of my car are actually Centric Ctek economy rotors because that was all that was available. They are holding up great and come off the track at 500+ degrees every session.
LargeOrangeFont is offline  
Old 06-07-16, 08:38 AM
  #8  
B O R I C U A
iTrader: (14)
 
KNONFS's Avatar
 
Join Date: Mar 2001
Location: VA
Posts: 5,360
Liked 8 Times in 8 Posts
Originally Posted by LargeOrangeFont View Post
Buying them before they are slotted is cheaper. Stoptech slotted or drilled rotors start out life as Centric Premium blank rotors.

The rotors on the back of my car are actually Centric Ctek economy rotors because that was all that was available. They are holding up great and come off the track at 500+ degrees every session.
Good info, thanks for sharing!

I am planning on replacing all 4 rotors this fall
KNONFS is offline  
Old 06-09-16, 10:36 AM
  #9  
Let's get silly...
iTrader: (7)
 
RockLobster's Avatar
 
Join Date: May 2004
Location: Rosemount, MN
Posts: 1,702
Likes: 0
Liked 3 Times in 3 Posts
Slots and cross drilling are a back and forth issue. Lots of OEMs (BMW M cars, Porsches, etc) use them. But in practice, racing, ive not found them to show any significant advantage. In fact ive seen cheap cross drilled rotors crack, many times.

What I have found is that good quality brand name blank rotors (brembo, centric premium, etc) that i've had cryo treated by frozen rotors have lasted by far the longest. Cheap rotors can warp and crack, even more so with slots or holes. Good quality blanks last a long time and give consistent performance. But ive observed roughly doubling that life with cryo treatment.

This is lots of first hand evidence over 10 years of racing.

Last edited by RockLobster; 06-09-16 at 10:39 AM.
RockLobster is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Rotary Compression Tester.Com
Rotary Compression Tester.com
0
04-09-16 08:22 AM


Thread Tools
Search this Thread
Quick Reply: Slotted rotors = waste of money?


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: