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I know this setup is probably overkill for the majority of the driving I do, however - an insufficient braking system is one of the main reasons I have not been back to the track post-turbo...
You CAN put together OEM stuff that will work, but it will be compromised and eventually consumables will have paid for a BBK. Something is wrong with Thumpetto's setup. That's an anecdote i'd throw out in the context of this scenario. Not to mention that a street car on 15x7s probably isn't really the same sort of car we're talking about here. And i'd agree with him, a BBK isn't needed for a street car with 15x7s.
So you are complaining that your rotors are noisy, but also complaining that they aren't floating. You do realize that floating rotors make a ton of noise that you will hear at low speeds on the street, right?
Its just no one talks about certain parts and how noisy they are. I have mesophonia, and it was a large undertaking getting used to very expensive loud parts (squeaky xidas, and rattly brakes) The parts i added, like mazdacomp engine mounts, or delrin CA bushings, i knew about the nvh increases before hand.
im not saying the noise is bad, just trying to help another member that might appreciate all the details.
That's because when people need a BBK, they need a BBK. If noise comes with it, that's fine, because if you need a BBK, chances are you aren't building a Cadillac street car.
What happened to spending a few hundred bucks ducting the stock rotors before dropping a grand on a kit? Once big rotors get too hot, the rate they cool off will be dictated by airflow anyway. I'm sure the extra area helps, but I bet the airflow helps more. Are there any racing series that allow real pads and ducting but not bbks?
I would try ducted XP10/8 on centrics before going full bling.
One thing I discovered recently when looking to get the car trackable is that:
Big brakes require 15x10 wheels
Big wheels require body work and narrow springs
Narrow springs means might as well upgrade to Xidas
Might as well duct brakes first since that has no dependencies
What happened to spending a few hundred bucks ducting the stock rotors before dropping a grand on a kit? Once big rotors get too hot, the rate they cool off will be dictated by airflow anyway. I'm sure the extra area helps, but I bet the airflow helps more. Are there any racing series that allow real pads and ducting but not bbks?
I would try ducted XP10/8 on centrics before going full bling.
One thing I discovered recently when looking to get the car trackable is that:
Big brakes require 15x10 wheels
Big wheels require body work and narrow springs
Narrow springs means might as well upgrade to Xidas
Might as well duct brakes first since that has no dependencies
Yeah, I don't buy the argument that you have to have the biggest wheels and tires and the biggest brakes and the biggest spring package and the biggest turbo setup to be trackable. I think incremental improvements in any of the components are the way that most of us proceeded. We didn't jump right into a 350 plus horsepower car with massive brakes and massive slicks and 1000 lb Springs. That's how Race shops build race cars but that's not necessary to build a trackable dual duty car. I started off on used street tires on 15x6.5 and then graduated to used SM6 and DIY bilsteins. I did a lot of track days and had a good time learning. I wasn't trying to win anything. I just wanted to have fun. As I used stickier tires and went faster I needed more brakes.
Its just no one talks about certain parts and how noisy they are. I have mesophonia, and it was a large undertaking getting used to very expensive loud parts (squeaky xidas, and rattly brakes) The parts i added, like mazdacomp engine mounts, or delrin CA bushings, i knew about the nvh increases before hand.
im not saying the noise is bad, just trying to help another member that might appreciate all the details.
I find it interesting that you're a contrarian for most everything that folks talk about here, especially re:949/TSE (and v8r?). That said, I sympathize with your mesophonia, but all the research I did on miatas before even buying one led me to believe that the cars just about always have some sort of rattle or noise and that they weren't quiet cars by any stretch of the imagination. I think that no one talks about this stuff because the expectation is that racecar parts don't usually meet anyone's definition of 'quiet'.
Last edited by ridethecliche; 05-16-2018 at 05:55 PM.
Ran into a couple small unexpected things, but nothing terrible. The PFC 7754.11.16.44 pads are designed for the caliper with the bridge bolt, not the big W retainer so I had to grind out the center of the backing plate to fit.
I called PFC and they do not yet make a 7816 wilwood style pad.
And the wheel weights hit the outer edge of the caliper so I had to rebalance my tires. I ended up just static balancing them in the center of the wheel and they feel fine.
Also had to do some backing plate trimming.
Also had to cut a lot off the rear plate to fit the sport bracket and rotor. Used some tin snips to cut about 3/4" off the edge of the backing plate and a chunk off where the caliper now sits. ( no pics of that tho)
Took it out, did a 30 to 5mph, 60 to 5mph, then an 80 to 5mph to bed the pads in. So far everything seems really nice. The pads are quiet, pretty dusty but I have been pretty hard on them so that might add to it. Only really need to adjust the proportioning valve when I get some more time. The pedal is nice and high, firm, and so far it's easy to control the pressure to not lock up the tires on hard stops. Time to get back on the road course!!
I lusted after a bbk for years. I finally get the radial mount wilwoods with ap jhook rotors. They look awesome. They fit 15x7 rims without a spacer. They also are still fixed rotor ( 350dollars per rotor and it aint a floating) They clunk loudly over bumps. They take (estimate) 3 times the pedal force to stop.
I know about the issues with stock brakes, but ****, they work, and the rotors are cheap, pads are about the same, and the op doesnt seem to brake hard enough to merit a bbk.
Im all for spending money all ***** nilly, but just standing my ground with a different perspective.
But all of these complaints are a product of a bad BBK design. Not your fault, but whoever picked the components didnt specify them correctly. The differentiation is a place like Flyin Miata or Moss, that make their own BBKs by buying components from manufacturers. So you could have a dealer-designed BBK or you could have a manufacturer designed BBK. Depending on the resources and expertise in these companies, either one could be terrible or amazing but you would hope whoever sells it has also validated the design and performance.
Floating rotors dont need to clunk. Some floaters use conical washers or spring clips to preload against the hat so there is no rattle, but the rotor can still float with thermal expansion. It could have been the pads moving around inside the pad cavity as well - pad spring clips can stop that kind of thing.
3 times the pedal force? This means that caliper piston sizes were wrong or the Master Cylinder needed to be changed. Either way, poor design unless they state you need to change other hydraulic components in the system to balance the output and retain pedal feel. If you had found anyone else running this kit, they would have experienced the same problems as you?
BBKs are all about thermal capacity and the ability to shed heat faster than stock. Some actually do stop the car faster (shorter distances) than stock, because they manipulate some small percentage of balance to the rear of the car (factory front bias for liability). But in general, BBKs allow you to beat on the brakes without getting into a fade situation. On track, you want them running in the proper temperature range for the pad you are using. Too much ducting or running too cool for a particular pad will hurt performance, while too hot will do the same. Ducting should be used ONLY when indicated by temperatures, and even then only as much as needed to get into the optimum temperature range of the pads being used.
If you never fade brakes on your car and you are not cracking rotors from heat cycles after a few events, or wearing pads super fast, there is no real advantage to a BBK besides possibly weight savings. Higher horsepower cars have more momentum, so the brake demand is higher - but this only means the temperature comes up more quickly and stays higher baseline as compared to the same brake system on a lower power car. In a BBK, the rotor may have the ability to cool more quickly than a stock rotor not because of ducting but because of vane design. So in addition to more capacity, it also has more efficient cooling.
05-16-2018, 08:52 AM
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