E-Bodies.org Cuda Challenger Forum

Technical Shop => Wheels, Tires, Brakes, Suspension & Steering => Topic started by: bc3j on February 06, 2020, 08:07:20 PM

Title: Brake pads
Post by: bc3j on February 06, 2020, 08:07:20 PM
A question for the group. For brake pads, does anyone consider the friction coefficient of the pad? I have read that DOT code FF is the minimum for a performance pad. Thoughts? Any particular brand you use?
Title: Re: Brake pads
Post by: Chryco Psycho on February 09, 2020, 06:24:36 AM
I use Power stop 3 series pads
Title: Re: Brake pads
Post by: dodj on February 10, 2020, 05:21:58 AM
I never considered it, or even knew it was there to look at.
When I changed to Baer cross drilled and slotted rotors and used Bendix ceramic pads with the original calipers, my seat of the pants braking meter was impressed. Not overly scientific....
Title: Re: Brake pads
Post by: bc3j on February 10, 2020, 07:16:50 AM
Thanks. I'm just playing around with the relationship of the all components of the braking system with the parts I got laying around and thought I'd throw that out.  Right now I'm experimenting with getting close to a 14:1 ratio between the caliper bore area to the master cylinder bore area. Several sites seem to center around that ratio as being optimal for manual brakes. I'll see how that will actually work out once on the car. Right now I'm at 11:1 and braking is good just trying trying to improve upon that. Seems like increasing the ratio is an improvement. Next change will bring it to 13:1, but I'll have to wait for spring. Thanks again.
Title: Re: Brake pads
Post by: RUNCHARGER on February 10, 2020, 08:16:59 AM
Not very scientific but I used the repro Hemi Master Cylinder with 79 R-body calipers on my orange car and it worked excellent!
Title: Re: Brake pads
Post by: bc3j on February 10, 2020, 09:13:17 AM
Thanks. Same calipers I'm using. It's just a long winded way to say I'm switching master cylinder bore size. Mathematically, all cars have a ratio between the area of MC & caliper, I'm just goofy enough to figure it out. In the long run it really doesn't matter.  I always am curious about you guys success in different setups on this forum. A wealth of info. I'm glad you guys are gracious enough to share it. If you have the caliper bore & mc it's just a little math.
Title: Re: Brake pads
Post by: RUNCHARGER on February 10, 2020, 11:46:13 AM
No, I admire you figuring it out. I just threw a dart and got lucky. Much smarter to do the math before jumping in and spending $$$.
Title: Re: Brake pads
Post by: Chryco Psycho on February 15, 2020, 02:58:01 PM
When you get it wrong it is awful .
I have driven a few cars that could barely slow down with both feet pushing as hard as you could , you really need to have it all sorted out , , bore sizes , number of pistons in each caliper etc
Title: Re: Brake pads
Post by: Katfish on February 15, 2020, 05:12:13 PM
Quote from: bc3j on February 10, 2020, 09:13:17 AM
. If you have the caliper bore & mc it's just a little math.

So what is the math on this?
Title: Re: Brake pads
Post by: 73440 on February 15, 2020, 05:19:58 PM
https://acceleratingtech.blogspot.com/2011/05/master-cylinder-math-explained.html

Some math here.
Title: Re: Brake pads
Post by: bc3j on February 15, 2020, 07:01:13 PM
Quote from: Katfish on February 15, 2020, 05:12:13 PM
Quote from: bc3j on February 10, 2020, 09:13:17 AM
. If you have the caliper bore & mc it's just a little math.

So what is the math on this?
I have a spreadsheet for this but it's just the area of a circle (using caliper bore, master cylinder bore) then the math (radius x radius) x Pi 3.1416. Then divide MC area by caliper area. You'll get a ratio then. It's just some sites I found suggest a ratio of near 14:1 for manual brakes. There's a spreadsheet on, I think, forbbodiesonly, but I can't find it. Has some good information for getting braking information.
Title: Re: Brake pads
Post by: Katfish on February 16, 2020, 05:20:52 AM
Excel does make it easy,  curious how you plan to get to 14:1

With a 7/8 MC and 2.75 Caliper (I think largest stock) it works out to 9.9

7/8 MC = 0.6013   
2.75 Caliper = 5.9396
Ratio   9.8775 (5.94/0.60)   
Title: Re: Brake pads
Post by: bc3j on February 16, 2020, 12:24:11 PM
MC 1.031 = .8343
Caliper 2.75 = 5.9396
14.0557

Excel too. Makes things easier.
Come spring I'll see how it works out.