Brake rotor vent thickness... Does it matter? | FerrariChat
Buy

Brake rotor vent thickness... Does it matter?

Discussion in 'Technical Q&A' started by GrandmaSideways, Nov 3, 2008.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. GrandmaSideways

    GrandmaSideways Karting

    Sep 10, 2008
    85
    #1 GrandmaSideways, Nov 3, 2008
    So I have a set of wilwood solid disc brakes on my car at the moment.
    They're great, stop excellent, blah blah blah - Long story short, I like them.:-D
    Anyways, an opportunity to purchase a set of slotted wilwood rotors came up. However, they seem a alot thinner than my current used set of spare disc. By thinner, I mean overall width - but more than just the wear, I'm talking about the size of the vents.
    Unfortunately I don't have a set of vanier calipers, however my rudimentary measurements seem to indicate what's on the car now is 20mm, and the new ones are 10mm wide vents...
    Am I opening up a can of worms here?
     
  2. GrandmaSideways

    GrandmaSideways Karting

    Sep 10, 2008
    85
    #2 GrandmaSideways, Nov 3, 2008
    Got a few photos...
    [​IMG]
    [​IMG]
    [​IMG]
    Gee... Well since I could fit the NEW brake rotor INSIDE the space the vent takes up... No, I don't think I can use the new ones, hahahaha.
    I didn't realize that the difference was so significant!
     
  3. andrewmr

    andrewmr Formula Junior

    Jun 7, 2005
    320
    Bucks County, PA.
    Full Name:
    Michael
    #3 andrewmr, Nov 4, 2008
    Yes it matters... and you most certainly could be opening up that can.

    Let's use your numbers. If you assume your stock rotor is 20mm thick and you have new pads in the calipers then you should have a situation where the pads are just standing slightly off of the rotor surface. As you drive your car the brake pads wear (as does the rotor) and the material goes away. As this happens the piston in the caliper extends further and further out of the hole/bore to maintain that close proximity of the pad and the rotor. That's the way it is supposed to work and when you get to the end of the pad everything is still ok.

    Now replace your stock 20mm rotor with a rotor that is only 10mm wide. And let’s assume you allow the pads to wear completely down as in the case above. Is there still enough piston stuck in the bore? That could be a factor? You could do a number of things to offset that, but they are all work arounds.

    Another thing to consider is the material itself. The rotor is a big heat sink. Reducing the width of the rotor reduces the mass which will affect the amount of heat you could place into the rotors. On the track that most certainly would be an issue. On the street it may not be.

    I can see where have a smaller/thinner rotor may be a good thing, but I would question the value behind doing so. As always, it’s your call.
     

Share This Page