03Screamer

iTrader: (2)

I'm VERY interested in this set up. I'd personally prefer the 6 piston caliper, even if the cost was a little bit more. I haven't really read much of this thread, but do you plan on putting a rear set up together, with a parking brake? Also, the option for 355mm rotors would be nice as well.

Havok_RLS2

iTrader: (9)

Brother you know I'm down. Any support I can give please just ask.

kbiz

14" kit would be the second phase... the 6 piston calipers will utilize the same bracks so I'll include the information for that. I don't know right now how much testing we'll be able to do with the 6 pistons, but perhaps we'll be able to test the 6 pistons with the 14" kit. One factor on the 14" kit concept is that they'll most likely not be compatible with the same calipers as the 13" kit... though I'm still looking into the options for that. The rears I'd also like to do... I'm debating whether or not to wait for the Wilwood kit to come out for the rears since they'll have the exact rotor with e-brake drum available and the part will be available for individual ordering. If I can find a rotor hat with drum that will work then I'll proceed with the rear kit. Though custom hats can be made, I don't want to get into that as it opens a ton of questions and concerns and will most likely not be able to fall inside of my pricing goals and ease of assembly for the DIYer. I'm not a big fan of the line locks nor having an additional caliper for the e-brake. My goal is to make everything as simple as possible and if I could assemble the kits by means of off the shelf components, that would be perfect. As it is, however, the brackets will still have to be fabricated... but that will be pretty simple and will be the only area of work for anyone who wants to make a kit happen for themselves.

DZeckhausen

Besides the difference in rotor annulus, requiring a different cut on the calipers to fit over the larger diameter rotor, you also need to consider piston sizing. The key equation to consider is the brake torque equation:

Brake Torque = Effective Radius * Clamping Force * Pad Cf

Effective Radius is approximated by the distance from the center of the hub to the center of the pad. It describes the "lever arm" of your brake system and is analogous to the length of the handle on a torque wrench. Double the length of the handle and you can cut the amount of force applied to the wrench to get the same torque.

Clamping Force equals hydraulic pressure * total effective caliper piston area. As you increase the size of the caliper pistons, you increase the clamping force.

Pad Cf is simply the coefficient of fiction of the pad at the temperature you are considering for testing. Remember, pad Cf is not a single number, but changes with temperature.

You can make several simplifying assumptions that clean things up a bit. Assume the pad Cf is constant, since you'll likely be picking the same pad compound for the 13" or the 14" kits and you can assume a temperature well within the flat part of the Cf vs temperaure curve. Assume you won't be changing the master cylinder, so the hydraulic pressure remains constant relative to the brake torque at the rear brakes.

As a result of these assumptions, you can use a spreadsheet to determine what the caliper piston size should be when moving up from 13" to 14" rotors in order to avoid changing the bias of the brakes.

You should do the same with the 13" kit by starting with the stock, 1-piston floating calipers and calculating what piston sizes you should use for a 13" 4-piston system. But you need to remember to multiply the stock piston area by two to calculate "effective area" for a 1-piston sliding caliper. I've seen people forget this and end up with a front brake kit that has only half the required brake torque with the resulting huge rear bias and dangerous instability.

Ron Zarza

I've been following this thread from the begining and am very interested in the eventual outcome. What is your aproximate timeframe for kit completion?

kbiz

Thanks for the info DZeckhausen. I've been using comparisons of components offered by other BBK builders so far...

As far as the timeframe goes, I'm thinking I'll have my vehicle fitted sometime after Christmas... probably the beginning of January. Testing by zillinois will most likely be later than that because of his schedule... but at least I'll be able to report how my impressions are going from the stock non-brembos. I'll be doing my testing, hopefully, down at SIR in Kent... Once I have the fitment done on the brackets, I'll post what I've done on my vehicle and if others are in a position to test the set-up then they can report any findings as well.

Attached is a printout from PBC Brake calculator... I'm trying to stay within known combinations from other BBK builders.

r26

count me in

Ep3

iTrader: (10)

noice info from our stoptech sponsor

knight_white99

iTrader: (5)

Subscribing to a very interesting thread...

atlsupdawg#2

I'm definetly game on this one..Still would like to get some rough measurements of the brackets so I can see what can be done on my end in terms of machining them..Would stainless steel, or even inconel, be an option to fabricate the brackets from??

buzzardmountain

iTrader: (17)

Interested!

mberthia

iTrader: (5)

I would be interested also as I have been debating on a BBK for a while. At this time, the stock brakes will force me to stay on less challenging tracks as I'm not confident of their capabilities on harder braking tracks.

Is there a large selection of pad compounds available for this caliper ?

gringott

iTrader: (17)

Hope we have something off the ground soon because I don't think I can make it to 60,000 miles on these original stock pads. 52,500 and counting.....

DZeckhausen

You can get new Axxis D+ front pads for just $53 and rear pads for $30. As long as your rotors aren't dangerously under spec, this would be a reasonable stop-gap until the kit was finished.

Alternatively, you might be able to pick up a set of used pads from somone on the forum who has already upgraded to Brembo, StopTech, AP, etc.

gringott

iTrader: (17)

How are the Axxis D+? Good for street? Better than Hawk HPS?
I saw some guy had Hawk HPS for around a hundred for the set. Maybe I will check him out. Thanks.

KNS Brakes

iTrader: (2)

If you've got 50k+ miles out of your stock pads then I bet you are not an aggressive braker. So most any pad would be ok. Axxis are pretty good performers and inexpensive - but can be a bit dusty. Certainly better than the 'no namers' at autozone.

Most ceramics dust less - or less dark - but cost more. I've tried quite a few though and my undocumented, biased, OPINION is that metallic pads feel better. Ceramics always feel a little softer too me. I don't care about dust though - not one iota so keep that in mind.

gringott

iTrader: (17)

infantsam: Thank you.

DZeckhausen

Axxis Deluxe Plus pads are about the least dusty pads on the market. Axxis Metal Master are not much worse. If you've seen dust from an Axxis pad, then it must have been the Axxis Ultimate.

It is not possible to generalize that "ceramics dust less" or "metallic pads feel better" since the range of performance of pads is incredible. Ceramic is the "oat bran" of pad materials these days. Before that it was Kevlar and before that it was semi-metallic. Marketers convince people to ask for a single ingredient or technology, rather than insisting on a specific level of performance in various areas (maximum operating temperature, fade resistance, cold bite, dust level, rotor wear, pad life, noise, etc.). There are high performance pads with some ceramic content (and thus called "ceramic pads") that have aggressive bite and medium to high dust level. And there are other pads with ceramic content that have a low Cf (and thus feel "soft") which are also low dust. You need to look at each manufacturer's range of products and describe their performance. Remember, ceramic is just one of up to 30 or more ingredients in the friction compound. It just happens to be riding a wave of popularity at the moment, so marketing departments capitalize on it by tossing in 2% ceramic and calling the pad their "new ceramic compound!" Don't be fooled. Ask a brake expert for a detailed description of each pad compound in performance terms, not ingredient terms.

sakred

iTrader: (4)

im in for the 13 inch 4pot kit but would like to be the primary tester for the 6 piston 14 inch kit. il be going to my next track day on feb 12 and can give a nice comparison from the stocks tot he upgraded one. i also want to get tha back done aswell. i dont feel right doing somethign halfway. but anyways Kbiz you are doing us all a great service. let me know when i can begin to purchase the parts. i will deifnately give a full write up.

Hammad

kbiz

Inconel would be a better choice than SS but both could work. Inconel typically has a higher ultimate strength than Aluminum alloys... the only issue is availability. I don't know if there are any special requirements or processes required for machining Inconel and that's something that would need to be looked into.