WCMA Forum

Road Racing => Spec Miata => Topic started by: ChrisS on September 19, 2014, 02:15:49 PM

Title: Pulsing brakes?
Post by: ChrisS on September 19, 2014, 02:15:49 PM
Anyone else getting pedal vibration with the XP10s?

Chris
Title: Re: Pulsing brakes?
Post by: Al36rx7 on September 22, 2014, 12:50:27 PM
I have been using the Carbotech pads for last 10 years.  Never had any pulsation from the pad....  I have used XP8, XP10, XP12, XP20, RP2.  Always good to me.  Wonder if there is some pad build up on the rotor if the rotor is not warped (we've had this).  I have seen when switching brake compounds, but the rotors are still impregnated with the old pad (different compound) resulting in pad material build up.  We just lightly buffed the rotor face, and the pulsing was gone.  It worked for us this year...

Cheers.
Title: Re: Pulsing brakes?
Post by: ChrisS on September 22, 2014, 02:27:38 PM
I'm pretty confident that it's pad material build up.  I haven't tried buffing them off and re-bedding yet.  I tried with two sets of front rotors this year; both were new, and both did the same thing.  I'm thinking that the pads are getting out of their happy place for temperatures.  I'm getting more brake drag than I would like to see, which is probably contributing as well.

Are you running any brake ducting?  Granted it's a different car, but I imagine you have bigger braking events than me, with no extra time in between to cool them down...

Chris
Title: Re: Pulsing brakes?
Post by: Al36rx7 on September 24, 2014, 01:34:56 PM
On the old green car, I only ran ducting the last couple years.  But my front rotors were 1.25" wide.  Previous cars in the past I always ran ducts
Title: Re: Pulsing brakes?
Post by: 10cc on September 24, 2014, 07:19:57 PM
Before ducting, I was cracking rotors and blowing bearings often. I have serious brake ducting now, and can often run a whole season on one set of rotors, and never blow bearings at all. For the CC cars, Mazda, or somebody, has a cool ducting kit that fits behind the rotor and pushes the air into the centre back of the rotor so it blows out through the vented rotors. 3" hose from the front of the car to the ducts. Lots of air.
Title: Re: Pulsing brakes?
Post by: miataR on November 06, 2014, 10:10:53 PM
I was getting severe brake pulsing by the end of the season. I put new rotors from Mazda with XP10 brake pads.

It does look like there is a buildup of brake material on the rotors. The rotors are also showing a significant amount of wear (about 1/16 inch).

This is the first year back racing after a several year rest and my lap times have steadily improved over the season. The pulsing didn't seem to appear until well into the season so I suspect it is related to brake overheating as well.

Do other SM cars use different types of brake pads? What is your experience with them?


Doug