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Looking for biggest discs to fit under 15” - looking for safe after serious brake failure

So I have the wilwood 140-11020 11” 4 pot kit, wilwood adjustable bias, factory booster and disc brake master cylinder.

I can get a replacement caliper. I’m looking into if I can get a replacement bracket from wilwood.

Surprisingly the rim looks ok, lots of Ali flaked heat fused on from the caliper grinding away. But other than that looks like a polish will clean it up.

I need to double cheak my measurements but I think I can fit the 140-10740 6 pot brake kit.


Anyone ran that on here?

My 11.65" Baer Iron Sport (Cobra) rear brake kit, required some grinding off the caliper to fit inside 15" draglite wheels.
I would say a vast majority of the time, you'll need a 16" wheel to run a 12" brake kit (not all the time). From their site, it looks like you'll need 14.14" to clear with the 12.19" kit. Mainly would depend on the wheel design and backspacing.

I would just order another caliper + bracket, and go with a better pad for now. That will make a significant difference if you're still using the factory pads.

When you change your wheels, then go with a 13-14" kit. No reason to spend the money twice, very little resale value in used brake kits. I then would upgrade the rears (if you haven't), like I said earlier, it's a science, that's why I leave it up to guys like Cass to create a balanced system (or Baer / Stoptech / etc).
 
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To throw in a huge can of worms, here is Wilwoods catalog which displays bore sizes;
http://www.wilwood.com/Pdf/Catalogs/TechCatalog.pdf

Remember earlier, we mentioned the factory 2.75" single piston caliper on our braking systems, and how it worked fairly well (regarding brake bias with factory style drums, etc). Now, when we mention your current 4-piston setup from Wilwood, it's an astronomical difference in relation to factory; which effected pedal travel and braking performance.

In reality, the gains are slim upgrading. If you look at your current Wilwood 4-piston caliper, it has 9.6 sq. in. of total piston area. The 6-piston Wilwoods have 10.12 sq. in. of total piston area. Other than having the ability to run a slightly larger brake pad, there will be very little to no difference IMHO.

Check out the pad compounds available from Wilwood;
http://www.wilwood.com/BrakePads/BrakePadsApp.aspx

You can't really 'proportion out' a bad bias in the braking system;
http://www.stoptech.com/technical-support/technical-white-papers/proportioning-valves

Good luck and just do your research! Hope the links helped in some way.
 
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I'm running the dodge diplomat '82 master , prop valve and the disc and 11 inch rear brakes I took a booster from amazda 3 and fit it in it stops on a dime
nothing like good brakes

View attachment 585128

How did you come up with the Mazda/diplomat combo? This talk of the right size master has me thinking about if I have the right master combo for the task...
 
To throw in a huge can of worms, here is Wilwoods catalog which displays bore sizes;
http://www.wilwood.com/Pdf/Catalogs/TechCatalog.pdf

Remember earlier, we mentioned the factory 2.75" single piston caliper on our braking systems, and how it worked fairly well (regarding brake bias with factory style drums, etc). Now, when we mention your current 4-piston setup from Wilwood, it's an astronomical difference in relation to factory; which effected pedal travel and braking performance.

In reality, the gains are slim upgrading. If you look at your current Wilwood 4-piston caliper, it has 9.6 sq. in. of total piston area. The 6-piston Wilwoods have 10.12 sq. in. of total piston area. Other than having the ability to run a slightly larger brake pad, there will be very little to no difference IMHO.

Check out the pad compounds available from Wilwood;
http://www.wilwood.com/BrakePads/BrakePadsApp.aspx

You can't really 'proportion out' a bad bias in the braking system;
http://www.stoptech.com/technical-support/technical-white-papers/proportioning-valves

Good luck and just do your research! Hope the links helped in some way.

Thanks mate, I have been looking at the piston sizing as well. If I am to get a new kit, then there is no reason I shouldn't get as much piston size as possible IE the 6-pot set up. I have emailed Wilwood, but I doubt they will respond favourably. I had previously contacted them about getting a bracket to get the larger rotor size and was told a flat no, so I doubt breaking one of their brackets even, will get me a better response. But we'll see what they comeback with.

I'm not sure on the compound I have but I do have non slotted discs's so there are upgrades to the current system I can do, but looking at the costs, I may be better off with just going to a new set up instead.I seat have a line onto the 6pot kit for a good price at the moment.

I am also looking at Cass's kit, I'm just not sure if it will fit over 15" wheels

I know I should go to a bigger rim if I want more braking, but I love my 15's. They just suit the car perfectly. I will eventually get a set fo 18's as well, but I will still want the ability to go back to a 15 for a period look when ever I want.
 
well i took all the brakes from the diplomat , the booster was to big to fit in , so i went to the scrap yard i ve been dealing with for 30 years
i took the m/c with me and matched it up as close as possible with the measurement i took of the space. i made some brackets and fit it on
it really stops well and can lock them up easy with little brake effort. the only was that the column shifter hit the booster when trying to get into low 1
but i just finished a 700r4 tranny swap and had to modify the shifter anyway , am just about done. im waiting for drive shaft
so now i have my 355 gears and over drive tranny and running 2300 high stall torque, on the slant six twin weber set up headers ....
so im hoping april plating the car and working to the details
 
How did you come up with the Mazda/diplomat combo? This talk of the right size master has me thinking about if I have the right master combo for the task...
well when i do swaps i try getting the whole car , of same size , taking the whole thing cause i know it works.
so i knew it would be good for the b body. the booster was a unforseen bump in the road .
but it works fine even better that i though, anyway was better that no power bakes and 4 wheel warped drums!
 
I've found a couple of options, thought I'd see what people thought of these:
https://www.summitracing.com/int/parts/rsd-mdc62wkcs/overview/
No details on the caliber specs any where I can see, anyone know what size they are? 11" rotors.

http://www.classicperform.com/NewProducts/MoparBrakeKits/Mopar_Brake_Kits.htm
Are these the later molar brakes with the 2.75" pot? Can't find any details here either

Will Cass's Viper kit fit under 15's?

Or its back to wilwoods, Thing I don't like about the wilwoods is there lack of dust covers on the pots... but the 6 pots seem like the biggest at the best price... I would prefer some chunkier adaptor plates tho. The wilwoods are not as beefy as some of the others I've seen.
 
I've found a couple of options, thought I'd see what people thought of these:
https://www.summitracing.com/int/parts/rsd-mdc62wkcs/overview/
No details on the caliber specs any where I can see, anyone know what size they are? 11" rotors.

http://www.classicperform.com/NewProducts/MoparBrakeKits/Mopar_Brake_Kits.htm
Are these the later molar brakes with the 2.75" pot? Can't find any details here either

Will Cass's Viper kit fit under 15's?

Or its back to wilwoods, Thing I don't like about the wilwoods is there lack of dust covers on the pots... but the 6 pots seem like the biggest at the best price... I would prefer some chunkier adaptor plates tho. The wilwoods are not as beefy as some of the others I've seen.

I ran the Summit Racing (rebranded SSBC) kit with my Draglites, but back then, the cost wasn't as high as it is now. I would give Cass a call concerning the Viper kit, I never installed mine as I went with 18" wheels.

Cass sells an 11.75" kit with the 2.75" bore caliper for $600 as well. I've purchased axles, 2-brake kits, and a differential from him; everything has been outstanding. I don't think you'll find a negative review anywhere for Dr. Diff.

Factory brakes and a good performance street pad will be fine for what you're after. No reason to go exotic on an 11.75" setup IMHO!
 
I ran the Summit Racing (rebranded SSBC) kit with my Draglites, but back then, the cost wasn't as high as it is now. I would give Cass a call concerning the Viper kit, I never installed mine as I went with 18" wheels.

Cass sells an 11.75" kit with the 2.75" bore caliper for $600 as well. I've purchased axles, 2-brake kits, and a differential from him; everything has been outstanding. I don't think you'll find a negative review anywhere for Dr. Diff.

Factory brakes and a good performance street pad will be fine for what you're after. No reason to go exotic on an 11.75" setup IMHO!

I hear what your saying, but I am intending to finish a few things then run some track days and go-to-whoa's. I am also used to performance brakes in all my other project cars. She won't be just a car show cruiser. But granted I don't need ceramic super car brakes either. But to put it in perspective, I am considering going to a bigger wheel to support better brakes if I can't find a suitable option to fit my 15's. Brakes are important to me.
 
I've started chatting with Cass about the viper and 11.75" kits. I've dealt with cars before for Diff rebuild parts so I'm more than happy to work with him where possible.
 
I've broken down my options to two. Keen to hear peoples thoughts on the best braking:

Option one:
single piston caliper
11.7" rotor
New spindle/knuckle
mounts directly to the knuckle
2.75" piston - 5.94" piston area
Heavy set up

or

Option two:
6 piston caliper
12.19" Rotor
Existing spindle/knuckle
Used adaptor plate to mount the caliper
5.05" piston area (no details on piston size - assuming the piston size is stated as one size which is the standard)
Lightweight set up


Which is going to provide the best braking? I feel like the 6pot set up would, but the piston area is greater on the single pot set up.
 
I have similar to option one and am satisfied. I used the Dr Diff kit with 15/16 master cylinder. Just read April issue of mopar action magazine and Richard Ehrenburg claims this is a very good set up.
Hopefully others can give a comparison between the two options.
 
Bill, do you have a booster? or manual set up? I've also been considering going to a 15/16 or 1" master on my boosted brakes... but that is for later perhaps.
 
Bill, do you have a booster? or manual set up? I've also been considering going to a 15/16 or 1" master on my boosted brakes... but that is for later perhaps.
No booster. The car really brakes well.
BTW another mopar action magazine article awhile back mentioned that keeping the car level during braking is a big improvement. Stronger torsion bars and good shocks are helpful.
 
Ehrenburg commented on the 73 to 76 type disc conversion.

20180325_182318.jpg
 
I just picked a issue of mopar action. The guy did the brake conversion to his 67 belvedere and used 15 inch rims with 11.75 rotors its a good read.
 
Yep, the 11.75" combo is probably as good as it gets for a factory 15" wheel setup on a street car. 15/16" bore MC makes a huge difference, longer pedal travel but great brake modulation (with manual brakes).
 
Yep, the 11.75" combo is probably as good as it gets for a factory 15" wheel setup on a street car. 15/16" bore MC makes a huge difference, longer pedal travel but great brake modulation (with manual brakes).

Do you think the 15/16" master will bee too sensitive for a boosted application tho?

Challenge for the 11.75" kit is the weight of it, makes the cost of shipping scary.
 
Do you think the 15/16" master will bee too sensitive for a boosted application tho?

Challenge for the 11.75" kit is the weight of it, makes the cost of shipping scary.

Honestly, I'm not sure. I've never ran power-brakes, but I wouldn't change the MC bore size until you install the new calipers.
 
Start an email dialogue with Dr Diff. Tell him what you expect and see what the recommendations are for your car.
I'm a plug and play kind of guy, so the Dr Diff kit is better than the scarebird option.
 
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