FM Wilwood Rear BBK - Squealing like crazy
 

So I have the FM Wilwood rear BBK street version Flyin' Miata : Chassis : Big brake kits : Flyin` Miata four piston rear brake upgrade - street installed in the car with some StopTech drilled/slotted rotors. I'm also running the Wilwood front BBK from Good Win Racing along with a proportioning valve.

Last week I was finally able to go out and bed the pads. Followed the proper procedures and got the car all settled with the prop valve too. I figured the squealing would stop at some point but it hasn't. Car squeals from the rear brakes like crazy just as the car is coming to a stop. The fronts are Dynalite calipers with bp-10 pads and the rears are Powerlite calipers with Polymatrix E compound pads.

I've tried every type of brake pad lube, I've made sure everything in the rear brakes is tight. Only thing I haven't tried is changing pads. I was hoping someone on here has some experience with this setup and could shed some light on this matter. Is it the calipers? Pads? If it is the pads what would y'all recommend as a replacement? This car is a street car that will see some spirited driving and once the new motor is in it will put some decent power down. Any insight is appreciated, thanks!

It's your pad compound. E's aren't quiet, and IMO do nothing well. If you're happy with the BP-10's up front, then you don't need an aggressive pad and should get BP-10's for the rear too. You may need to add a bit more rear bias though, to your taste.

Shitty pads on shitty rotors, replace both with decent stuff.

E compound is useless. It's supposed to be a dual street/track compound, but (as you can see) it's as loud and dusty as a full-on race pad, but it lacks the high-temp characteristics of such.

I use BP-20s front and rear as street/autox pads, and am pretty happy with them for that.

I used to use B compound pads for track, but after melting a set at Laguna last week I'm following Savington's advice and switching to DTC-60s.

--Ian

yep.

Im in the process of installing OP's same setup, minus the pads. What rotor would yall recommend?

Solid, no vents, no slots, no holes. Don't overthink it.

Perfect. Thats what came with the set. Thanks

If you want to get fancy you can probably save a bit of weight going with a Goodwin V2 rear rotor. This is a rotor-on-hat design, V1 and V2 are dimensionally the same as a sport rear rotor (which is what the FM kit is designed to use), V1 is a steel disc (don't get that!) V2 is a cast iron disc. The Goodwin hats are not threaded though, so you need to use a nut with a bolt, which means you can't safety-wire them. To me this meant using the best hardware I could find -- aircraft bolts at roughly $60 to do both sides.

Is it worth the hassle to drop a pound per side? Probably not.

--Ian

I like the sound of less weight but it'll have to be after i get her on the road. Its amazing how much lighter these calipers are than stock. But for now I'll use what I have since its decent as is.