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Discussion Starter · #1 ·
So i had these lying around.

20151017_122709 by Darek Plaza, on Flickr

and i have all this space to work this winter

20151107_134839 by Darek Plaza, on Flickr

so i cracked out ye olde autocad

20151117_161057 by Darek Plaza, on Flickr

and it looked like it will work

20151107_183834 by Darek Plaza, on Flickr

So i did the logical thing. i ordered a bunch of 7075 t6 temper aluminium

Message_1448047048625 by Darek Plaza, on Flickr

then, i started machining:

20151122_175956 by Darek Plaza, on Flickr


20151124_174100 by Darek Plaza, on Flickr

20151204_150342 by Darek Plaza, on Flickr

looks better in aluminium than paper

20151122_160147 by Darek Plaza, on Flickr

turning the hats.

20151206_121118 by Darek Plaza, on Flickr

lining said hats up to drill

20151205_175904 by Darek Plaza, on Flickr

it fits! it fits good!


20151117_121141 by Darek Plaza, on Flickr

I went with the wilwood 30 vane ultralite rotor, 12.19 x 1.25 in. its 65$, and will hold up for autocross. plus its interchangeable with the heavier HD and GT series rotors for when i eventually really track the SOL.
 

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Discussion Starter · #2 ·
More Brake goodness

20151207_185127 by Darek Plaza, on Flickr

ARP 12 pt bolts drilled for safety wire to hold it together.

IMG_20151207_190813 by Darek Plaza, on Flickr

IMG_20151207_190838 by Darek Plaza, on Flickr

Weight comparison 5.3 lbs! in just the rotor.


Then i ran into a silly problem. I have DDM's stainless lines, and i didnt want to replace them. i had to adapt the M10 banjo to a 1/8 npt on the calipers. Way to go wilwood, i mean why would you do that?!?!

ear-977521erl_w_ml by Darek Plaza, on Flickr

here we go, an earls fitting that solves the problem, hasnt existed for 2 years now. so back to the lathe with a 5/8s hex rod of 317 stainless:

20151122_180059 by Darek Plaza, on Flickr

I know, still have sharp edges and there is no perpendicular hole for the banjo end. but i dont have a newer picture of those.

20151207_170055 by Darek Plaza, on Flickr

yes, i did put an indicator on my rotors to check if they are straight and centered. for anyone curious, off by a massive 0.0015 inches. compared to 0.0025 of the rotors i took off.

anyway, thats where i am as of today, just waiting on a M12 x 1.75 tap to use the stock brake caliper bracket bolts on my new brackets.

what do you guys think?
 

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Do you think you could reduce the size of your photos a bit, so we could see them all in one go? Each if these is larger than my screen, by a wide margin.
 

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Wow, that's pretty impressive. I like the 5 or so pounds weight saving too. :thumbs:

I always wondered if the custom brake jobs I've seen some people do were really worth it when you figure in the the expense of the custom parts and the potential difficulty getting stuff if something breaks. I guess that's way different if you actually machine your own stuff.

What, if anything, do you plan on making next?
 

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Discussion Starter · #6 ·
sorry about the big pictures, i just figured out how to put up pictures last night. they automatically re size on my screen and my phone so i didnt think it would be an issue.

the 5 lbs is just the rotor, there is lots more in the caliper. as for the issue of braking replacement parts, the rotor and caliper are off the shelf wilwood parts. replacements in a day or 2 from summit or jegs.

i think i might do the rears. i have a second pair of calipers that are with 1.38 in pistons. the ones i have for the front use 1.75 in pistons. coupled with an 11 or 10.5 in rotor i can get the bias to about 69% front bias. i dont know if thats too much front or not. i just have to figure out the parking brake. i am thinking of doing a second caliper for the parking brake.
 

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Nice job on the DIY setup, looks familiar :)



A couple things that I would have you watch for though. We originally tested the Ultralite rotors on our setup and under heavy braking we cracked both rotors that we were testing right by the 8 bolts that secure the hat to the rotor. Depending on how hard you run the brakes, that might not be an issue, but something to watch for. If you start to hear a "ping" noise after running the car hard and doing heavy braking, look for the cracks, they are probably there.

We tested the 1.5", 1.625" and 1.75" piston setups, the 1.5" reduced the braking force in the front too much, but had a nice firm pedal. The 1.75" increased the force in the front too much for us and the pedal was a little softer than we liked. If you come across a 1.625" setup you can switch to, I think you would like the balance and the pedal feel better.

As for the adapter to the brake lines, let me know if you have any issues with that setup you did. We manufactured custom adapters that go from 1/8" NPT to a M10 Banjo setup, works great, I can get you a set if you need them. Also, although I am not recommending you do this, but we tested it for quite a while, you can tap the 1/8" NPT hole in the calipers with a M10 thread for the banjo and it works really well. The M10 tap will go right in and you can tighten it down without any trouble. Since the 1/8" NPT needs a 11/32 (8.73mm) drill size and the M10 uses a 9mm the hole is just about perfect for the M10 tap. Once again, not saying anyone should do it, but it does work really well.

Hope that helps, and nice seeing some homebrew setups out there!
Let me know if there is anything else I can help you with.
Dave
 

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Discussion Starter · #9 ·
Thanks for all the info. I considered re-tapping the calipers, but i thought the raised wilwood logo would interfere with the banjo. I am curious about your fittings. Id love to see them.
Also, what did you guys do for hardware? I threaded the hat, and used arp bolts with a good sized unthreaded section that sits in the rotor. It looks like you have bolts all the way through and nuts, or did you thread the rotor and use larger bolts?
I also want to know what materials you used for the hat and bracket? Most kits i see use steel for the brackets, i used the same 7075 for both the hat and bracket. On paper it should be strong enough.
Again, thanks for all your input and feedback.
 

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Thanks for all the info. I considered re-tapping the calipers, but i thought the raised wilwood logo would interfere with the banjo. I am curious about your fittings. Id love to see them.
Also, what did you guys do for hardware? I threaded the hat, and used arp bolts with a good sized unthreaded section that sits in the rotor. It looks like you have bolts all the way through and nuts, or did you thread the rotor and use larger bolts?
I also want to know what materials you used for the hat and bracket? Most kits i see use steel for the brackets, i used the same 7075 for both the hat and bracket. On paper it should be strong enough.
Again, thanks for all your input and feedback.
Here are some pictures of the adapters that we made.







As for the rotor hats, we went with through bolts and locking nuts since that is more common to us. We have seen kits with the hardware going into the aluminum, but we can get a lot more clamp force with the through bolts. Once again if you are making your own kit it is one thing, since we are selling kits we have to make sure everything is a little more overkill than needed. Our caliper brackets are steel and black oxide coated. 7075 should be fine since it looks like you maintained pretty good thickness on the bracket, but once again for us the steel is a no brainer and will not have any issues longterm.

Hope that helps,
Dave
 

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Discussion Starter · #11 ·
i did a little research for torque on my hats. ARP recomends, i belive, 26 ft lbs on the bolts i used. i tested with 6061 aluminium, and i didnt pull out the threads till about 55 ft lbs. the 7075 has around double the yield strength, so i think the aluminium is still the weak link, but should be a really healthy margin for torque. my main goal for hardware was to make sure i didnt have threads pushing against the insides of holes and causing deforming after braking a few times. these fit the bill, and its less parts. i like less parts.

I wanna know about the rotor scallops. i coulnt find any definitive purpose for them and not every company puts them in, so despite putting them in my drawings, i didnt cut them into the hats. mostly because i had a really nice finish in the hat from the lathe, and no so good from the mill, i didnt want to ruin it, for the 0.1 lbs id save. was it just aesthetics for you? i will admit, it looks a little better.

also, what do you think is good for front rear bias. stock is way too much front. if i do the rears with the 1.38 piston calipers i have, it comes to just under 70% front bias. with the short wheelbase of the solstice, is it too little? too much? ( i highly doubt)
 

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Nice!!!! Good job on all that!
 

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Cool project. Nice pics too, it's a rare occurrence when someone post pics that completely fill my screen
 

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Discussion Starter · #15 ·
rear brakes, and working

well i now have a complete and working system! thats right, i beat DDM on this one!! in the end i ended up using the wilwood combination P brake calipers. in the end, there was no weight savings, but the new rear rotors are 11.75 in by 0.81 vented discs. they are the wilwood ultralights and weigh in at about 7 0r 8 lbs.


Machining





here is the caliper mounted. im not sure i am happy with this caliper. its radial mount, but wilwood wont provide any dimensions of this profile, it was a bastard to measure myself. and that part is cast, and has alot over flashing and inconsistancy left to right. i had to take them to the belt sander to clean them up. also, for an 11.75 in dia rotor, the bolts need to go alarmingly close to breaking out of the side. i moved the rotor and caliper out a bit so i have about 1/4 inch of aluminum before the profile is cut out. so there is actually enough meat there for the bolts.


mounted up



all done. the calipers mounted up, and i only had to bore out the hole for the handbrake cable from .5 in to .55 inches to make the handbrake work. the piston is 1.62 dia, and after testing, it looks like i didnt mess up my brake balance.
 

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Discussion Starter · #17 ·
Thanks, im proud of them. Im probably going to take them apart an anodize the hats at some point. But for now, im pretty happy with the result.
 

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Discussion Starter · #18 ·
Update, because it looks like a lot of people looked at this

the system has been working perfectly fine, i can lock up the wheels when i want, and have yet to crash or die. the pedal is quite soft though. as was predicted, and expected. i was thinking a larger master cylinder is an order.
i believe the stock one is a 15/16 bore. i was wondering if it might be interchangeable with whats used in corvettes or cadilacs. i imagine those cts Vs and Z06s have quite the beefy bore.
if i go the aftermarket route, 1 in and 1.125 are both quite common. if i go with the 1.125 in, the percentage increase of master cylinder area is about the same as the area increase of the brake piston. im pretty certain that will give me nearly identical feeling to stock.
so basically anybody know if its as simple as i assume?
 

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I doubt it is that simple. It is something I have looked into, but have yet had any luck finding info.
 
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