Big brakes for Mustang 2

timkins · March 18, 2019, 09:51:49 AM

I have a 32 Ford 2 Dr sedan that has a Mustang 2 front suspension. The brakes are Chevy metric and the piston has been enlarged to 2.75 inches. I am still not happy with the way it stops so I am looking to go to a larger caliper perhaps from a 79-81 Camaro or Firebird. Knowing that the larger calipers are not interchangeable with the metric calipers, I am looking for the brackets to allow me to install the larger calipers. Does anybody have any other solutions that will allow me to go to a larger caliper which offers more stopping power?

WZ JUNK · March 18, 2019, 10:19:47 AM

I am curious as to the current rotor diameter. I recently went from the stock Mustang ll to the 11 inch Ford rotor and the GM metric caliper. I did not see a noticeable improvement in the brakes. I hope you have better luck.

John

timkins · March 18, 2019, 10:35:17 AM

Quote from: "WZ JUNK"I am curious as to the current rotor diameter. I recently went from the stock Mustang ll to the 11 inch Ford rotor and the GM metric caliper. I did not see a noticeable improvement in the brakes. I hope you have better luck.

John

When I did the conversion to the metric brakes I went with the 11" Grenada rotor.

UGLY OLDS · March 18, 2019, 10:38:36 AM

Quote from: "timkins"
Quote from: "WZ JUNK"I am curious as to the current rotor diameter. I recently went from the stock Mustang ll to the 11 inch Ford rotor and the GM metric caliper. I did not see a noticeable improvement in the brakes. I hope you have better luck.

John
When I did the conversion to the metric brakes I went with the 11" Grenada rotor.

Any idea as to what size & kind of master cylinder/power booster you are using :?:
What is the ratio on the brake pedal :?:

Bob..

timkins · March 18, 2019, 11:03:58 AM

The master cylinder is a Ford 7/8 or 15/16(not sure which) under the floor with a 6.6 to 1 ratio.

enjenjo · March 18, 2019, 11:27:16 AM

There are several alternatives for bigger brakes, it just depends on how much you want to spend. There are a couple companies that make a bracket to use the D52 GM caliper that was used on the big GM cars and pickups. These require a true 11" rotor and have a 2 15/16" piston, and about 20 percent more pad area.

If you want to get more exotic, you can get 12" or even bigger rotors and Wilwood multi-piston calipers that are even more effective. Now you are getting into the area where some 15" rims won't clear the brakes, so you may have to go to a bigger rim.

Another thing to consider, if you front end has been converted to strutless lower control arms is the mounting strong enough to absorb the higher brake loads better brakes will put on the mounting points. You might want to consider that with an upgrade.

WZ JUNK · March 18, 2019, 11:32:51 AM

I went to the smaller bore master cylinder too, but I did not notice an improvement. I do not know my pedal ratio but the complete power brake unit was bought as an assembly from master power brake company. I have a 2 stage small booster. The next time I work on it, I am going to measure the brake pressure at each wheel.

Although the car stops well, it is not possible to lock up the brakes. I have 4 wheel disc brakes, and I am not sure it stops as well as the original 1954 Chevy did with 4 wheel shoe brakes.

John

timkins · March 18, 2019, 11:47:32 AM

I have the same problem as WZ Junk. I cannot get the brakes to lock up. It feels like I am using more pressure to stop the car than should be required. My car still has the struts so I do not think that is an issue. Enjenjo, do you have the name of the companies who have the brackets for the larger brakes?

enjenjo · March 18, 2019, 05:28:48 PM

ECI is one http://www.ecihotrodbrakes.com/mustang_pinto_discbrake_conversions.html

Mustang Steve has several https://www.mustangsteve.com/product-category/front-disc-brake-conversion-brackets/

There are others. Google GM D52 calipers on Mustang spindles.

timkins · March 18, 2019, 07:25:21 PM

Enjenjo, thanks for the info, I think I am going with ECI's kit. Probably the EC716 CK, that way there they source all of the parts needed to complete the job.

papastoyss · March 19, 2019, 03:55:21 PM

At one time ECI had a kit to install C4 Corvette (85-87) front brakes on a M 2 spindle. The calipers are aluminum, I believe the rotors are 12".

timkins · March 20, 2019, 08:47:22 AM

One of the problems I have for going to the larger brake system is I am trying to retain the 14" wheels I have on the front. I do not want to have to upgrade wheels and tires for an easier solution to the bigger brakes. After talking to ECI, they assured me the only difference would be the wheels would be moved out 5/16 of an inch.

nunattax · May 24, 2019, 01:12:13 PM

started out with a 7/8 bore m/c brakes were poor pedal bottoming out on the floor,soft. tried out a 1 1/8 too big couldn't move the pedal.eventually acquired a 1"m/c brakes are much improved im not locking the wheels there is no need to,justpowerfull brakes.double checked the pads they are still bedding in and are improving as the miles are put on them.sanded the discs and applied brake cleaner.happy with them.using 8" double booster and 90 degree under dash setup from kugel..give them a chance to bed in properly,bleed the system thoroughly

jaybee · May 26, 2019, 09:57:21 PM

I wonder if you have enough line pressure. Here's a calculator, hopefully it will at least rule that out as an issue. https://www.markwilliams.com/brakepedalcalculator.html

Or Yogi's has several different options for brakes on MII setups. http://www.yogisinc.com/index.cfm/page/ptype=results/category_id=1876/mode=cat/cat1876.htm

wayne petty · June 04, 2019, 02:38:29 PM

one might want to pickup a brake pressure tester.. https://www.summitracing.com/parts/ssb-a1704 several sources have these..

what kind of rear brakes do you have.. there are options sometimes to go to larger rear wheel cylinders.. including the snap ring retained versions GM used in the 80s and very early 90s.. 86 S10 Blazer with the 2.8 uses a larger wheel cylinder to increase rear brake bias. its 13/16 if i recall instead of 3/4" bore.

do you have a power brake booster? or just straight non powered brakes.

going to a smaller master cylinder bore increases the pressure to the calipers/cylinder with the issue of increased stroke. but you may find that properly adjusted brakes even with a slightly smaller master don't have excessive pedal travel.

going to a larger caliper piston/wheel cylinder piston increases the force on the brake friction materials.

huge hint.. there are a few... old bendix brake catalogs that show pictures of the brake master cylinders and wheel cylinders. but it lists the thread size and location and bore size.. some of them list the depth of the hole in the back of the master piston. some have multiple bore sizes listed together. i happen to have a safe line catalog version that makes it a little harder to cross to current part numbers in some cases.

brake bias is usually around 2/3rds for the front and 1/3 for the rear.. but that varies with tire size variations front and rear. if you have larger tires on the rear.. you need more brake bias to the rear.. larger wheel cylinders.. or larger caliper pistons. much harder to do.

i work on a friends car that has the same size calipers on all 4 wheels.. but the brake bias is still correct.. as the weight on the rear wheels and the size difference in the tread size. i wanted to do some testing but last time i did the brakes.. he went out and bought new tires.. and i did not want to flat spot those by accident.