Upgrading to 11.75” discs on the front?

-
In my recent experience, 77 Cordoba has rear-caliper spindles, 11.75” rotors, brackets, and pin-style calipers. That will fit a body- early a if you use later a uca or ball joint adapter sleeve.
 
I'm glad I got my parts years ago. I don't have to think about it, I just need to put them on. I used E-Boogers disc brake swap found on Mopar Actions website, Disc-o-tech I think it was titled.

Hope it all works out easily for you.
 
Last edited:
i will need new calipers too correct? Ive read the 80’s calipers allow the brake hose to be in a more neutral position and the 79 and earlier calipers can put the hose in a bind

I’m not aware of the brake hose hole moving from 79 to 80.

call Dr Diff or email him with a picture of your calipers
 
I’m not aware of the brake hose hole moving from 79 to 80.

call Dr Diff or email him with a picture of your calipers

i just got done talking with cass from dr diff, great guy! He told me the 80 and newer style calipers for rear mounting them for the cleanest and most bind-free hose routing otherwise the 79 volare calipers i have would have to remain upside down.
 
In Andy's defense, his math was fine for what he was trying to show. He was expressing the percentage difference in piston area and simply factored out pi and the radius conversion to simplify the math a tad. The answer's still the same - ~24% difference.
That is correct. When comparing areas you only have to compare the square of the diameters. Everything else cancels out. Old engineer trick. Just do the math that needs to be done.

The Wilwood calipers will reduce brake force over a factory 2.75 caliper. You can get the brake force back by reducing the size of the MC but then you might cause a problem with the rears. There are no free lunches with brakes. Everything has to stay proportional and in balance. Dropping piston area on one end of the car by 24% with no compensating changes could be dangerous.
 
What are the correct calipers i need? I believe the ones i have are 79 volare calipers which are 2.75 pistons but from what im reading when you rear mount those calipers theres potential for the brake hoses binding or hitting the control arm? The calipers i have now are upside down because the hoses i had wouldnt work with the calipers right side up.

Upside down calipers is a bad plan since you won't be able to bleed them. Doctor Diff sells calipers with dual bleeders so they can be mounted in any location. That is a very simple and very clever solution.
 
Upside down calipers is a bad plan since you won't be able to bleed them. Doctor Diff sells calipers with dual bleeders so they can be mounted in any location. That is a very simple and very clever solution.

they are that way now, i bled them off the car and they have worked fine upside down but i would like to do thinks right if im gonna upgrade to the larger rotors.

Ive been in contact with cass from dr diff and he told me about his new calipers with dual bleeders. pretty nice setup
 
Got my first batch of parts in. Usa made timken bearings, not too thrilled that the timken seals are made in taiwan but i guess better than china. Got the bendix pads as well, they are listed on summit as riveted but these are bonded which im happy about, ive never seen a brake pad with a burnishing compound on it though.

According to bendix the blue stripe is a titanium burnishing compound that eliminates the need to bed in the pads.

3125BE1A-00D5-4841-83F7-2DAEFFA033BF.jpeg


20CAF051-60FA-41EC-AF51-EA816E2FB2E7.jpeg


6574CCCB-F5FD-425E-B324-8BEDD258335D.jpeg


A2A2A4FD-7385-48AB-97B9-359B5A8E4DA2.jpeg
 
Just put my order in with doctor diff, had to wait a month for the 11.75” brackets to be back in stock, ordered a pair of the 2.75” bore new powder coated calipers, stainless brake hoses for rear mount calipers and the 11.75” brackets
 
Is the 15/16 bore absolutely necessary? I have the 1-1/32 bore now.

I run 1 1/32 but I have pin calipers. It’s a hard pedal and takes some force.

not sure if the slider caliper bores are larger or smaller.
 
I run 1 1/32 but I have pin calipers. It’s a hard pedal and takes some force.

not sure if the slider caliper bores are larger or smaller.


Im not sure but i think i have the smaller bore calipers now. Using the 1-1/32 master and changing from 2.6 to 2.75” calipers wont it make the pedal feel softer?
 
Im not sure but i think i have the smaller bore calipers now. Using the 1-1/32 master and changing from 2.6 to 2.75” calipers wont it make the pedal feel softer?

yea. I think they should help. You might find a happy medium
 
I'm running a complete 73 A body front suspension with 11.75 rotors and slide calipers. I would rather have the pin ones but I had the brackets sitting on my shelf.
I used the shields again cause they were on the shelf. I'm using a master for an 80 Grand Fury 1.03 bore and also have GM rear calipers. IIRC the lines were for 73 A body. Pedal is a bit spongy but stops well. Thought about trying a 15/16 master.
20200113_174152.jpg
20181123_134056.jpg


20190309_104348.jpg
 
Last edited:
I'm running a complete 73 A body front suspension with 11.75 rotors and slide calipers. I would rather have the pin ones but I had the brackets sitting on my shelf.
I used the shields again cause they were on the shelf. I'm using a master for an 80 Grand Fury 1.03 bore and also have GM rear calipers. IIRC the lines were for 73 A body. Pedal is a bit spongy but stops well. Thought about trying a 15/16 master. View attachment 1715706239 View attachment 1715706240

View attachment 1715706246

from what ive read going to a smaller bore master will make them more spongey or basically there will be more travel
 
yesterday got the 11” ssbc rotors off along with the caliper brackets and brake dust shields.

Tonight i removed the races that came in the new 11.75” stop tech slotted rotors. Installed the races for the timken bearings, cleaned, painted and reinstalled the dust shields, packed the timken bearings with lucas xtra heavy duty grease. Installed the new slotted rotors. Installed new 11.75” rotor caliper brackets along with new 2.75” piston calipers that i bought from dr diff. I love how the calipers have 2 bleeders so you can mount the caliper in any position. Just lack installing the stainless braided brake hoses.


F47C3B4C-076A-4B24-889E-DD8867EAF296.jpeg




0FEA9531-B669-4D35-B6CB-FF3F85939EB6.jpeg




357BA42F-A38F-401E-B928-1ABE7E5150F5.jpeg




16A41AE1-489E-4AC4-BEA5-05968F930BD3.jpeg
 
-
Back
Top