Thread: Slotted rotors noisy?

Results 1 to 15 of 15
  1. #1 Slotted rotors noisy? 
    GT Level Member MBruneaux's Avatar
    Join Date
    Oct 2009
    Location
    Canterbury, CT
    Posts
    417
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    I've read a couple places where people say that at low speed they can hear what sounds like a "flutter" from their slotted rotors? Has anyone experienced this or heard of it? thanks
    2001 Grand Prix GTP - Daily Driver12" front brake upgrade ('05 Monte), Raptor tune, Open cone, Front and rear strut tower braces, SS brake hoses, BMR trailing arms, ZZP 3" catted downpipe, Dorman front sway bar, GMPP rear sway bar, solid trans and engine mount, flipped dog bones and Borla exhaust.
    Reply With Quote  
     

  2. #2 Re: Slotted rotors noisy? 
    SE Level Member
    Join Date
    Jan 2009
    Location
    connecticut
    Posts
    117
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    I have drilled and slotted rotors and they do make a noise as you discribed. its so faint though you would never hear it with the windows up. only time i can hear is when driving by parked cars or a wall the sound bounces off of them.
    K & N cai / 3" downpipe / hi-flow cat / u-bend delete / 180 T-stat / ceramic coated plog & crossover / Overkill pcm / 3.5" pulley / zzp stage 1 TB / auto lite 104's / msd wires / poly mounts / slp front and rear sway bars / bmr trailing arms /
    Reply With Quote  
     

  3. #3 Re: Slotted rotors noisy? 
    GTX Level Member cerick08GP's Avatar
    Join Date
    Sep 2009
    Location
    Wisconsin
    Posts
    782
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    I haven’t noticed any change in noise levels.

    Ten years of continuous driving excitement and counting!
    2008GP
    ||HV3 insert||PowerSlot rotors w/Hawks||LED interior||MSD 8.5mm
    2002GP||sold
    Reply With Quote  
     

  4. #4 Re: Slotted rotors noisy? 
    GT Level Member MBruneaux's Avatar
    Join Date
    Oct 2009
    Location
    Canterbury, CT
    Posts
    417
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by GMPUNK View Post
    I have drilled and slotted rotors and they do make a noise as you discribed. its so faint though you would never hear it with the windows up. only time i can hear is when driving by parked cars or a wall the sound bounces off of them.

    What brand do you have? I was eyeing these: Brembo Sport Slotted Rotors or Performance Parts and Accessories Catalog - ThePartsBin.com

    I'm replacing both my hubs and want to get rid of this pulsation once and for all.
    2001 Grand Prix GTP - Daily Driver12" front brake upgrade ('05 Monte), Raptor tune, Open cone, Front and rear strut tower braces, SS brake hoses, BMR trailing arms, ZZP 3" catted downpipe, Dorman front sway bar, GMPP rear sway bar, solid trans and engine mount, flipped dog bones and Borla exhaust.
    Reply With Quote  
     

  5. #5 Re: Slotted rotors noisy? 
    SE Level Member
    Join Date
    Jan 2009
    Location
    connecticut
    Posts
    117
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    I have bear rotors,they were about $110 ish each
    K & N cai / 3" downpipe / hi-flow cat / u-bend delete / 180 T-stat / ceramic coated plog & crossover / Overkill pcm / 3.5" pulley / zzp stage 1 TB / auto lite 104's / msd wires / poly mounts / slp front and rear sway bars / bmr trailing arms /
    Reply With Quote  
     

  6. #6 Re: Slotted rotors noisy? 
    Awaiting Confirmation
    Join Date
    Jul 2009
    Location
    aowdnawi
    Posts
    23,292
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    Get the 12" upgrade, money better spent than slotted rotors.
    Reply With Quote  
     

  7. #7 Re: Slotted rotors noisy? 
    GT Level Member MBruneaux's Avatar
    Join Date
    Oct 2009
    Location
    Canterbury, CT
    Posts
    417
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by matt5112 View Post
    Get the 12" upgrade, money better spent than slotted rotors.
    I may do that, are the single piston worth it or the double that much better?
    2001 Grand Prix GTP - Daily Driver12" front brake upgrade ('05 Monte), Raptor tune, Open cone, Front and rear strut tower braces, SS brake hoses, BMR trailing arms, ZZP 3" catted downpipe, Dorman front sway bar, GMPP rear sway bar, solid trans and engine mount, flipped dog bones and Borla exhaust.
    Reply With Quote  
     

  8. #8 Re: Slotted rotors noisy? 
    Awaiting Confirmation
    Join Date
    Jul 2009
    Location
    aowdnawi
    Posts
    23,292
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    Well consider that the more you upgrade the front, the more you move the brake bias to the front.

    Theres only so much traction in the front and if you have too much brake force in the front compared to the rear then the fronts will lock up first.

    I'd just do the 12's and the stock calipers for now and see if you like that.

    But before that again, I'd try a higher performance pad first.
    Reply With Quote  
     

  9. #9 Re: Slotted rotors noisy? 
    SE Level Member
    Join Date
    Apr 2009
    Location
    California
    Posts
    4
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Slotted rotors only make a notable whirring sound under heavy braking. With regular driving you'd be hard pressed to make out any sound whatsoever with the windows up.
    Reply With Quote  
     

  10. #10 Re: Slotted rotors noisy? 
    resident snitch gtpinsc's Avatar
    Join Date
    Jul 2008
    Location
    sumter,south carolina
    Posts
    6,432
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    my powerslots make no noise at all.

    02 GTP with mods 05 GP for DD
    Quote Originally Posted by SuperSport View Post
    The majority of the people here are potheads who want to buy good condition parts at junkyard prices.
    Reply With Quote  
     

  11. #11 Re: Slotted rotors noisy? 
    GTP Level Member OrangeL67's Avatar
    Join Date
    Nov 2009
    Location
    Michigan
    Posts
    634
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Ive got drilled & slotted rotors. They hum when you hit the brakes really hard, other then that, there is no difference besides better stopping power and less brake fade

    VS cam build 13.01@107 316whp/ XP build #1 12.78@110 334whp/ XP build #2 12.56@113 347whp
    IS3 Cam build (Ready to put out some serious numbers)
    Reply With Quote  
     

  12. #12 Re: Slotted rotors noisy? 
    Awaiting Confirmation
    Join Date
    Jul 2009
    Location
    aowdnawi
    Posts
    23,292
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    Quote Originally Posted by OrangeL67 View Post
    there is no difference besides better stopping power and less brake fade
    How does having slots/holes increase the coefficient of friction of your pad?

    pad fade is probably what you're experiencing and that's fixed by getting higher temp pads.

    If you REALLY want to cool things down, create a venting duct for your brakes. that'd really keep the fade at bay.
    Reply With Quote  
     

  13. #13 Re: Slotted rotors noisy? 
    GTP Level Member OrangeL67's Avatar
    Join Date
    Nov 2009
    Location
    Michigan
    Posts
    634
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by matt5112 View Post
    How does having slots/holes increase the coefficient of friction of your pad?

    pad fade is probably what you're experiencing and that's fixed by getting higher temp pads.

    If you REALLY want to cool things down, create a venting duct for your brakes. that'd really keep the fade at bay.
    I have ran durulast Gold C-max pads on my car since the fiirst week I bought it. I changed over to DSR's after about a year and a half.

    The drilled holes allow air to circulate through the actual brake rotor, which does intern keep temps quite a bit lower, probably as low, or lower than a vent duct could. The slots take away the smoothness of the rotor surface, and the edges create friction that helps the pads grab on better, but studies have shown that it also wears your pads down quicker. So Yes.. Better stopping power and less brake fade

    VS cam build 13.01@107 316whp/ XP build #1 12.78@110 334whp/ XP build #2 12.56@113 347whp
    IS3 Cam build (Ready to put out some serious numbers)
    Reply With Quote  
     

  14. #14 Re: Slotted rotors noisy? 
    Awaiting Confirmation
    Join Date
    Jul 2009
    Location
    aowdnawi
    Posts
    23,292
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    Quote Originally Posted by OrangeL67 View Post
    I have ran durulast Gold C-max pads on my car since the fiirst week I bought it. I changed over to DSR's after about a year and a half.

    The drilled holes allow air to circulate through the actual brake rotor, which does intern keep temps quite a bit lower, probably as low, or lower than a vent duct could. The slots take away the smoothness of the rotor surface, and the edges create friction that helps the pads grab on better, but studies have shown that it also wears your pads down quicker. So Yes.. Better stopping power and less brake fade
    Did you change pads at the same time as rotors?

    Did you notice an increase in the brake preformance when changing pads and rotors or just rotors?

    And holes actually decrease the velocity of the air travelling through the venting vanes. Less velocity, less cooling.

    Slots are only supposed to aid in removing of gases, but gases only build up when you're bedding the pad, not after you'd bedded them.

    The pads rely on something to make contact with, you decrease this surface area, you decrease the total possible braking force.
    Reply With Quote  
     

  15. #15 Re: Slotted rotors noisy? 
    SE Level Member
    Join Date
    Apr 2009
    Location
    California
    Posts
    4
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    There are performance merits for slotted and/or drilled rotors in wet weather conditions in which water is cleared from the pad/rotor interface. With slotted rotors you get better initial bite, but the slots have a cheese grater effect on the pads, thus accelerating their wear. From my understanding the cheese grater effect provides a persistent "fresh" pad surface during braking which deters glazing of the rotors/pads during heavy use. That being said unless you're putting your car through racing conditions or have an issue with wet weather braking, you'll be hard pressed to extract any benefit from a slotted rotor.
    Reply With Quote  
     

Similar Threads

  1. Noisy supercharger at air intake
    By Purple Plazma in forum 3.8L V6 Supercharged (L67)(L32)
    Replies: 23
    Last Post: 04-21-2010, 09:46 AM
  2. Noisy Supercharger. Bad Coupler?
    By JoelW98GTP in forum 3.8L V6 Supercharged (L67)(L32)
    Replies: 3
    Last Post: 12-05-2009, 05:57 PM
  3. Where to get over sized slotted rotors?
    By boomboom in forum Brakes/Suspension/Chassis
    Replies: 10
    Last Post: 07-19-2009, 11:45 PM
  4. noisy flex
    By gotboost3 in forum General Tech Discussion
    Replies: 2
    Last Post: 04-11-2009, 01:22 AM
  5. Drilled/Slotted or both?
    By GP2003GT in forum Brakes/Suspension/Chassis
    Replies: 28
    Last Post: 04-20-2008, 12:43 PM
Tags for this Thread

View Tag Cloud

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •