NiklasFalk

iTrader: (1)

And add the thicker caliper due to about 4mm thicker pad (I don't think the AP's are 4mm slimmer than the Dynapros, but checking will know).

Paging 15x10" with ET40 (assuming no lip) + 15mm spacers?

bbundy

I've made a few upgrades over the years. 1" master cylinder and Sport calipers in the rear but I can say the setup works pretty well on a 300+ hp track car that turns laps ~10 seconds under Spec miata track records while weighing 2500 lbs with driver.

I am partial to Cobalt friction pads and never worying about bedding pads as well. less than stellar results with Carbotech. Hawk DTC 70/60 seemed decent but I dont think last as long. I seem to like cheap Wilwood BP10's for autcross and street with Axxis ultimates in the rear for consistant bite from cold to slightly warm. No problem at all swapping pads back and forth between Cobalts for the track and never worying about bedding them in.

OGRacing

iTrader: (1)

BULLYING?!?! Dude we got anough jackasses saying drilled rotors are supermegaawsome. if you want to be one of those idiots, go for it. but quit throwing mud in this thread. i'm here to help

hornetball

iTrader: (4)

To be fair, I don't think I've ever seen drilled rotors recommended by anyone on mt.net. Such a recommendation would quickly come under severe criticism I think. I can't speak for other forums though. Don't bother with those.

I think Niklas' point is that this thread is pretty theoretical or "cost no object." I do find it interesting, but I'm not finding a lot here that I can apply.

Early on you stated the following as a ground rule for the thread:

Yet, I find the practical application posts by guys like Bob, Emilio and others to be valuable. Perhaps a combined approach, i.e., "here's a practical system that worked in application X" along with the theory as to why it worked when something else didn't . . . .

Just thinking out loud, not trying to throw mud.

OGRacing

iTrader: (1)

Your absolutely right. we have gone over some basic application improvements, and no hands dirty building of anything. we have also gone over why cheap race pads are cheap. same with rotors and other components. I do have a set of test pads from PFC and hawk. I need an experienced driver/team to do a test with. That way I can make a "get you hands dirty and here are the results video and data"... It's been hard trying to find a team willing to participate in the test. It seams every team is in bed with carbotech, or too poor to do a test.

OGRacing

iTrader: (1)

i need to brake this thread up... it's seriously flipping long and people are starting to repeat themselves.

OGRacing

iTrader: (1)

i'll post this for NiklasFalk as he can't seem to find the page 3 button.

that is true. Allot of manufactures will keep a knuckle or the caliper bolt pattern and offset to aid in some kind of cost saving measures. i actually have no idea why they do that. but they do.

Remember in a braking system "more" is not better, it's just more. remember we are trying to build a complete a braking package.Taking a caliper from one car, and adapting to the other. before you do this you need to take some considerations into account. piston area in the calipers, Rotor offset, and overall braking balance.

Piston area.

Brake Tq can only be changed by 3 Dynamics in a brake system, Rotor Size, Pad compound, and hydraulic advantage. Hydraulic advantage the difference in size between your master cylinder, and your caliper pistons. if you want more Tq increase your pistons, less decrease your pistons. same goes for the master cylinder. you want more TQ? decrease your Master cylinder size. it will increase your hydraulic advantage. ***before we go out messing with master cylinder sizes and piston sizes there is a point of no return.*** the aspect that nobody thinks about but is important has to do with the brake pedal. As a pedal travels thru it's motion you do lose some advantage the further away from the driver it gets. We find at almost 90* on most pedal assemblies the driver would lose leverage. loss of that leverage would make the pedal harder to push. by decreasing the master cylinder size, or increasing piston size you're increasing the distance the pedal needs to travel. so it will take less effort from your foot to stop, but your trading that effort for pedal distance. try and keep the sweet spot of the pedal (@90*) at the point of where you start to modulate your brakes.


Rotor offset

Declaration happens exponentially faster than acceleration. think of our miata's, with 500hp almost every stock component will snap under that much power and acceleration. every miata can decelerate 4x faster than a 500hp miata can accelerate. the idea that i'm trying to put into everyones mind is 2000hp but in reverse. Everyone would agree that is allot of force. that's the force your braking components are under. When we design a big brake kit, the rotor needs to be squarely centered in between the hub bearings in order to stop the bearing from getting torn to shreds. as an example of what not to do, I bring up the unnamed unethical corvette shop again. They built their own big brake kit for c5/c6 corvettes and proclaimed it was "better than brembo.". that was a fed flag for me because brembo is a multi billion dollar a year brake company, and these guys are 4 idiots with a cnc machine. first question i asked them was "did you center the rotors in between the wheel bearings?" they answered with "why?", to me that means 'NO we didn't think of that'. every kit they installed on peoples cars blew out one skf corvette wheel bearing ($300-$500ea), this happens at every event. so make sure when you go to an non-oem rotor that the rotor offset is identical.

Overall balance

Big piston calipers, huge rotors can make your braking system feel like complete garbage. A personal example. before i was a brake rep or knew anything about brakes, i did a track day. i took a set of porter fields street pads out and burned them up. I absolutely cooked the snot out of them. They didn't like to work, but they would slow the car down. I knew the pads where toast, so i ordered a set of hp+ pads. I couldn't tell you why i ordered fronts only, and left the toasted porterfield pads in the back. I beaded in the hp+ on the street and thought "man these feel much better.". I went to an auto cross the next weekend. The track started with a long straight followed by a sweeping right turn. first run, I charged hard, came to the braking Zone, reached for the brakes, and there was nothing but white smoke. I flew 10 yards off the track and into a berm. Two big black marks from my front tires lead all the way off the track. My Front tires had all the braking power in the world, the rears were nowhere to be found. to put it into engineering terms the Fronts where at 90% braking and the rears were around 10%. the new pads had an increase of 30% more TQ, to yield to 90% worse overall performance. Although i had "upgraded" the Front brakes, it gave me worse performance than if i had left the burnout pads on the car. Yes you can increase the caliper sizes and get more torque out of the front wheels, but without balancing that increased TQ to the rear you're going to make the braking performance (ability to slow the car) worse. the Idea out of a braking system is that you want to use 100% of the tires. 100% of all 4 tires to slow the car. as the car stops weight is transmitted forward. at this point the rear tires have less weight on them and less traction. my point is that,it is not hard to upgrade rear braking components to handle the lightened traction. but everyone seems to forget that we do have brakes on the rear of the cars that need love too.



to answer your question. yes, you can bolt allot of equipment onto "other" hubs. without balancing the equipment out F->R then you're not really building a better braking system. make sure those rotors are centered. or the money you save avoiding an engineered brake kit will go toward wheel bearings. watch out for how much you increase piston area or you might need more pedal stroke than is available to you.

cyotani

iTrader: (8)

Maybe updating your first post to a FAQ would be a good idea for easier access to the information provided in this thread.

OGRacing

iTrader: (1)

it is in desperate need of clean up. i'll wok on it.

mr_hyde

iTrader: (4)

I agree the basic info should also be in a sticky but I like the discussion happening too. By nature of an open Q&A, the topics will drift all over the place. It might be messy, but it is a good read for anyone who uses their brakes in anger on a regular basis.

DeerHunter

Agreed. It's also the dead of winter here and answers I've received or information I find pertinent will likely be re-read once the snow melts. I would say leave this thread as it is and make a sticky with the "good bits".

emilio700

iTrader: (3)

FWIW, the recently released AP Miata kit is a slightly modified Mini kit. We are trying to get our hands on a kit to test but the US importer doesn't seem terribly interested. If that does not bear fruit, we'll get one direct from the UK.

My CAD guy is overlaying the AP drawing with our 8 and 9". Hope there is room.

OGRacing

iTrader: (1)

Essex wont give out a demo or marketing unit to club racers. these guys are the ones that supply team corvette racing, and Stevenson Motorsports.

PFC has a Z34 caliper and 11.75 mini kit already built. i'm reluctant to say it "works" as the mini's required a 25mm spacer to clear the wheels. With the size of the 34 caliper we would need to run steel 15" wheels.

emilio700

iTrader: (3)

Wasn't planning on getting, nor asking for a free AP kit to test. We are a vendor so we will buy it. Even that is not simple though.

OGRacing

iTrader: (1)

Preaching to the quire.

chilidip

iTrader: (3)

Couldn't agree more. Put Wilwood BBKs on my AP2 and although I saved a ton of weight on the calipers, the rotors were almost twice as heavy as stock (or so it felt). The car never felt the same. Should have just swapped the calipers.

bbundy

With Wilwood I got all the cad data from the Wilwood site and made solid cad models of a bunch of different wheels I had along with the brake kit way back when I originally picked the Mini Dynapro Radial kit.

Looks like AP is using slightly bigger pistons. I used slightly bigger pistons on a Kit I did on a 323 GTX to get proper bias because it is an extremely front heavy car compared to a miata. I didn’t think the larger pistons gave as good of feel as what I have on the Miata when it was done. They still worked good though.

bbundy

The thicker roter is going to be a problem for spoke clearance like I said.

OGRacing

iTrader: (1)

it uses a .20mm rotor just like the track speed kit.

ThePass

iTrader: (3)

Damn good thread, this. It's true that there is a lot of "this is best if cost is no object" but the education is very important. No, most miata racers, with the budgets we have, are not going to make the switch to a system that is $1,000 per corner, but there's more take away from this than to just think everything the typical miata track car is running is inferior.

It's invaluable to understand the actual range of offerings out there and what you get for the money with each component. That way, when even choosing the pieces to a budget set up that does have compromises, you can make an educated decision about where to spend the extra coin and where to skimp.

Funny side note, was on the phone with PFC the other day and the moment I mentioned I had a miata the guy goes "Oh, do you know Johnny??" Haha

-Ryan