Brakes: RAD Ideas : Mustang GT and Cobra brake adapter bracket update

[sbca96]

I haven't really posted much on any of the three forums in the last year or so, but I
thought I would give an update on what I have been currently working on. Many of
you will recall that I created an adapter back in 2006 to mount 1994-2004 Mustang
brakes onto a Studebaker spindle, using the existing Studebaker drum brake hub.

http://forum.studebakerdriversclub.c...read.php?64873

Carrying 3, only slightly, different brackets was frustrating and not cost effective. So,
I have been in the process of redesigning the bracket to work in all three variations.
Using steel to cut material costs, reduce machining operations and the manufacturing
cost. First step was to borrow a SN95 steering knuckle and create a solid model of
it, and the hub for a design study :



https://www.youtube.com/watch?v=xMqHObo2WDo

I also started a model of the Studebaker knuckle assembly to compare dimensions of
the two more closely. I will add to this when I get the dimensions I need.



https://www.youtube.com/watch?v=EvNHQtZbGJA

I completed the initial 'GEN II' change, but need to take my Avanti apart to get a few
dimensions rechecked. I want to trial fit a few hubs to check the hub face to flange
tolerance that Studebaker allowed.

Next step after this is to finalize the rear brake adapter design. The rear bracket hole
spacing (center of wheel to caliper holes) is different (unlike the front) as they used
the same caliper for GT or Cobra in the rear, just moved it outward for the larger rotor.

That's all I have right now, just felt the need to share.

If anyone is interested in a Cobra setup for their Studebaker, I have one set of Cobra
6061-T6 brackets left, as long as the steel design works out as I plan, this set will be
the last of the aircraft grade aluminum brackets available.

Tom

[Paul Keller]

Good to hear an update, esp. re the rear (needed) disc system.
Paul TK

[sbca96]

Thanks Paul.

This is what I have been up to, hanging out over at the 2nd Gen Camaro forum building
a car for my wife ...

http://www.nastyz28.com/forum/showthread.php?t=188458

Tom

[sweetolbob]

Thanks Paul.

This is what I have been up to, hanging out over at the 2nd Gen Camaro forum building
a car for my wife ...

http://www.nastyz28.com/forum/showthread.php?t=188458

Tom

BTW, nice mod to make the flush mount stereo in the post. Post more, Bob

[sbca96]

Thanks Bob, it was quite an undertaking cutting a stereo apart, but I figured that it was
worthwhile since I can utilize it on the Avanti. I kinda stay off most of the Studebaker
forums for reasons I'm sure you are familiar with. I thought I would give it a shot again
to test the waters, so far SDC has been ok, but I left Racing Studebakers again for now.

Tom

BTW, nice mod to make the flush mount stereo in the post. Post more, Bob

[sbca96]

Another update, I removed the 13" Cobra brakes and the hub, then the GEN1 bracket to
check my measurements against the SN95 assembly model created in the video above.



https://www.youtube.com/watch?v=wOM3RZnMA9s

The GEN1 bracket is added in this video as transparent to show the spindle.

Tom

[sbca96]

First version of the PBR caliper and 13 inch rotor.



More detail added to the PBR caliper.



Tom

[sbca96]

Been away from this for a while....

Pulled apart the rear brakes on the Avanti to measure and create 3D models of the GT setup. I am
also researching the Cobra rear setup parts to order and create mounts that will accommodate both
setups. Seems possible.





Tom

[Scott]

Hi Tom,
Are you using Autocad? Solidworks? Looks good.

[Mangusta1969]

Cobra Brake Adapter Questions

Been away from this for a while....

Pulled apart the rear brakes on the Avanti to measure and create 3D models of the GT setup. I am
also researching the Cobra rear setup parts to order and create mounts that will accommodate both
setups. Seems possible.


Tom

Tom,

Keep us posted on your progress. Your CAD drawings look great. What mods will the rear wheel brackets require to the original Stude Avanti hubs, if any? What is the size of the 2003 Cobra rear rotors?

A bolt on setup would be great for me, but I could live with some minor machine work, too...

Steve

[karterfred88]

Looks great Mike,
The only problem for me would be the use of 13" rotors, as most would prefer to retain 15" wheels. I'm thinking of doing a rear axle change to a Ford Exporer 8.8 with rear discs already there at 11.3 inches and 15's fit as they are the standard size. Looking at cost as a part of this brake change, what are the chances an Explorer front disc, also 11.3 would work, after machining the front hub to allow the rotor to be a slip off type? These rotors are available from $22.00 each as a hat only, makes "rebraking" real cost effective!!

[sbca96]

Hi Tom,
Are you using Autocad? Solidworks? Looks good.

Scott,

It is a 3D modeling software.

Tom,

Keep us posted on your progress. Your CAD drawings look great. What mods will the rear wheel brackets require to the original Stude Avanti hubs, if any? What is the size of the 2003 Cobra rear rotors?

A bolt on setup would be great for me, but I could live with some minor machine work, too...

Steve

Steve,

The brackets I have on the rear of my Avanti are modified Ford parts, they simply bolt onto the
inner surface of the axle tube flange using 3 of the 4 bolts. The hub is the same one the drum
is mounted to. I pressed out the studs and drilled them just like the front hubs and used those
same shouldered studs to center the rotor. The only thing that I found was over the years the
rear hubs get distorted from the forces generated pulling the hub off the tapered axle shafts. I
had my hubs put on a lathe and just cleaned up on the front face. This is not a requirement, I
also found that a solid blow from a short sledge will move the hub face a tad to fix runout issues.

Cobra rear rotor is 11.65 inches and it is vented, while the GT is 10.5 and solid.

Looks great Mike,
The only problem for me would be the use of 13" rotors, as most would prefer to retain 15" wheels. I'm thinking of doing a rear axle change to a Ford Exporer 8.8 with rear discs already there at 11.3 inches and 15's fit as they are the standard size. Looking at cost as a part of this brake change, what are the chances an Explorer front disc, also 11.3 would work, after machining the front hub to allow the rotor to be a slip off type? These rotors are available from $22.00 each as a hat only, makes "rebraking" real cost effective!!

Mike? hmmm.

The problem with using a different rotor design from what matches the Cobra is the offset of the
hat and the rotor diameter. Ford designed the front setup to use the same caliper mounting hole
for both GT and Cobra. The calipers actually make up for the difference in rotor size. If I was to
go with a different smaller rotor (to replace the 11 inch GT I assume is your question), it would
require a different caliper and possibly different mounting hole locations. That would require the
use of different caliper mounting brackets for the front again - which I am trying to avoid. With
a simple machining to the outside edge of the stock Studebaker hub, the GT rotor slides on just
fine. This is a one time modification just like the stud change, from that point on you just get a
Ford part, open the holes a tad (as shown in my threads) and they slide onto the shoulder studs.

The GT version of this setup allows the use of 15" wheels. Only the Cobra setup needs 17+.

For the record, GT rear rotor is $29 and the front is $32 dollars at your local auto parts store.

Tom

[sbca96]

Cobra/Mach1 Caliper Bracket added

I ordered the Cobra/Mach1 caliper bracket which allows the use of the 11.65 inch Cobra rotor to
be used in the design. The setup in use on my Avanti for years now has been the 10.5 inch GT
rotor and caliper bracket. Ford used the same hydraulic caliper, but changed the pads, rotor and
mounting to fit the two different versions. The plan is to make ONE bracket that mounts to the
Dana 44, but allows either setup to be installed. Here are the preliminary Cobra additions :





And a view of the Ford parking brake setup, which actually works with the stock Studebaker pull
cables already on your car.



Here is a short video showing the difference between the two setups.



https://www.youtube.com/watch?v=D5ZNmHBKaY0

Tom

[karterfred88]

Mike,
Since you're using Mustang brakes now on your Avanti, are you still using the Bendix booster? Have you considered or tried switching to a Hydraboost system not dependent on engine vacuum?

[bezhawk]

[QUOTE=karterfred88;872908]Mike,
Since you're using Mustang brakes now on your Avanti, are you still using the Bendix booster? Have you considered or tried switching to a Hydraboost system not dependent on engine vacuum?[/QUOTE
I'm using a hydroboost system for the Paxton Novi blown R4 I'm building.