My 84 FB came with these and I've tried everything I Can think of to stop the brake squeal. From about 30-0 mph its sounds like a train locking up the brakes on the tracks. It's embarrassing! Super frustrating with these nice brakes.

I've tried a soft race compound, a hard race compound. And I just paid $130 for ceramic wilwood pads and still have zero luck. The disc surface is new an din perfect shape. I've greased teh area the pad rides in and used the red sticky back antisqueal on the back of the pads. I think it may be the entire mounting bracket that is vibrating.

I called aerospace and they said that is the nature of that brake kit and told I needed to buy their $1200 street kit. I'm not sure happy with that answer. Anyone run these? Any ideas?

https://shop.aerospacecomponents.com...3mazdarx7.aspx

 

First, thank for the link to another brake option for RX7s! Didn't know this was a thing. Also pricing is not terrible at all.

I would be inclined to blame the drilled/solid disk rotor for the harmonics that is generating the squeal. The reality is that you have a drag racing brake kit on a street car. Racing brakes/pads/rotors (even ones that are vented) can be noisy because, well, its racing and nobody on a race track cares about noise or brake squeal. In fact, I find that brake squeal reassuring in my race car because it means they are working and I am likely to make the next turn.

Mitigate your losses and sell the kit you have to a drag racer and get the kit made for the street, They will work better (larger diameter rotor) and the calipers will have more clamping force.

 

They're using Hawk pads. Hawk (race) pads tend to squeal.

 

They came with hawks. I've since tried 2 other compounds as well as third ceramic now. Which are supposed to be the quietest pad as they vibrate at a different freq. So I don't think its the pad thats making the squeal. I believe its either disc as mentioned above or the entire caliper mounting bracket. Was going to try and add an additional mounting point to see if I can eliminate the bracket/assy vibrating.

This is a budget setup so I'd rather not have to spend 1200 on a new brake kit if possible. Would like to exhaust all other options first.

Thanks!

here is a short video.

 

I heard of a trick form an old time hot rodder to put some high temp silicone backing between the caliper and the caliper mount plate. I just tried this and it eliminated 90% of the squeal. I can actually hear now some it is coming form the back though its minimal. I used red Loctite on the caliper bolts I'll have to stay on top of it and check them but its drivable at least now. Just back from a 2 hour cruise. Pretty happy with it. At least I seem to of isolated the issue. Doesn't seem to be the the rotor.

May try welding another mount/bracket to the existing caliper mount as well.

 

Glad your silicone helped ... it makes sense that it would.

I wouldn't go too crazy with the red loctite though, that stuff is strong and those bolts will give you trouble coming out later unless you use some heat on them. And fwiw you shouldn't need it for the caliper mounting bolts anyway. Normal torque to specification should do it.

Blue loctite doesn't need heat to break.

 

That squeal you're hearing from up front is the whine of the supercharger... lol
Got more pictures of the whole car and engine bay?

 

My worry was I now have 1/8" of silicone between the caliper and the mounting bracket.

 

I wish! No supercharger on this build. Just the Individual throttle body intake. Its a $500 Junk yard 5.3 LS. Alum block and heads with a smallish cam mated to a 350z 6 speed trans and an 8.8 rear end.

 

Sorry, I read your description but didn't get it right. I thought you put a layer of silicone between the pad and the caliper.

Fwiw I can't imagine there's actually 1/8" of silicone between the caliper and its bracket? It must have squeezed out when you tightened the caliper bolts into the bracket.

I looked at the aerospace website, maybe a less expensive fix compared to going with the full street kit would be to replace just the drilled/slotted rotors with the standard ones?

 

Techno toy Tuning has several nice options using Wilwood components. I use them on my rx3 and love them. no noise at all.

 

Silicone as in a piece of 1/8th inch thick silicone rubber cut to the shape of the bracket. Not RTV or similar. So I couldn’t truly torque down the caliper properly. Which was the reason for the red Loctite. Basically just experimenting and trying to isolate the noise.

aerospace did return my email stating for $650 I could upgrade to their street kit. Basically, they send me a caliper/bracket/rotor. That’s not too horrible I suppose.