Manual Brake System Trouble Shooting: Expected Line Pressure?

[carbuff]

I have found the solution for all of our braking concerns! And it's cheap too!!!

Brembo Red Disc Brake Caliper Covers

[Ron Sutton]

Originally Posted by carbuff

I have found the solution for all of our braking concerns! And it's cheap too!!!

Brembo Red Disc Brake Caliper Covers

That is hilarious.

I'm sure they're licensed by Brembo ... NOT.

.

[Track Junky]

This is great stuff guys.

I think I'm just going to add a "Thanks Ron" to my sig.

[Flash68]

Originally Posted by Ron Sutton

Hi Dave,

I have worked with AP calipers a LOT ... but I am not familiar with those part #s, other than knowing they're 6-piston calipers.

Two questions:
1. What is/was their intended design purpose?
2. Can you measure the piston sizes & we'll run some calcs?

.

I got these from James Shipka as they were used on his One Lap Camaro a couple years before he switched. Their intended purpose is dual street/track. I have the slotted-only version (not drilled). Here are the links he sent me:

http://www.brake-pros.com/product_fi...0S%7Ebroch.pdf
http://www.brake-pros.com/product_fi...0S%7Ebroch.pdf

Piston sizes (Hey Rob, look at that!) we measured to be as follows:

1.05 / 1.05 in the rear and 1.5 / 1.25 / 1.05 in the front.

They also came with some Mintex Xtreme and Raybestos pads. Not sure which we will try out first.

After some discussions with a couple people I was planning on starting with 3/4 / 3/4 MC bores.

Thanks Ron

Originally Posted by FETorino

Guilty as charged.

You see a lot of oversized rotors in the PT world because of the aesthetic value of filling the wheel. Many of us know better and still commit the crime.

I fell victim but reading this reminds me why I really wanted to run smaller rotors out back.

Yep. Nothing looks worse than an 11" rotor inside a 20" wheel.

But then a lot of this talk is really helping to validate that form can be trumped by function and then form can actually be aesthetically appealing because of it.

Originally Posted by FETorino

Technical questions for Flash, this should be good.

hey Roberto..... see this post by your new Crew Chief below. He has posted this more than once.... FYI.

Originally Posted by Ron Sutton

6. I want people to ask questions. There are no stupid questions

[Ron Sutton]

Dave,

You didn't give me all the details to work with, so I "assumed" a 6-1 pedal ratio & worked up a chart with 13" rotors & 14" rotors. If you have different details, let me know what they are & I'll plug them into my calcs.

Also, since I don't know what pads you're going to run, I adjusted the pad CoF until I got the 14" rotor version to about 4000# braking force. That will require pads in the .52 CoF at the temperature range you'll use them at. That is the lower end of race pads. You may want less braking force on the street.

For less braking force, go to a pad with a lower CoF. For more braking force, go higher on the CoF.

[Flash68]

Thanks Ron.

Yes, 6:1 on the pedal ratio and 14" front and rear rotors.

I need to see if I can get an exact number/model # of the brake pads I got. I was also considering going with Carbotech XP-12 and/or XP-10 pads. I used them on my previous Wilwood setup (XP-10 front / XP-8 rear) and liked them.

Any experience with them?

[Ron Sutton]

Josh (Banko) has an award from Wilwood, so he's upgrading his brakes. Josh is the one that started this thread because his car is not braking strong enough. He PM'd me the system he's considering.

Brake piston sizes
Front: W6A (1.75,1.38,1.38)
Rear: C6Zo6 (1.3,1.3,1.3)

Rotor diameters
Front: 14"
Rear: 14"

pedal ratio
6.25:1

Master cylinder bores
Front: 0.75"
Rear: 0.75" or 0.875"
Brake pad brand & compound name
Front: PolyMatrix H
Rear: Hawk HPS

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I ran the calcs on this system ... an whoa Baby ... it swings the pendulum too far the other way. In the chart below, this is the system on the left. Look down at the total braking force #. It would have 7000# of braking force, which would simply lock the wheels up upon braking.

Now look at the chart on the right. By changing the pad compounds & the M/C sizes, we adjust the total braking force to about 4000#. That is a strong braking system.

Did you guys ever watch the Lassie TV show?
If you did, you remember the Dad always sat down with Timmy at the end of the show to explain the moral of their lesson. This was a planned in moment every show. The writers called it the "Ya know Timmy ..." part of the story.

Well ... Ya know Timmy ...
The lesson here is when building your braking system working out the details is just as important as buying great parts.

[67goatman455]

I'm still completely baffled that the brakes on my 99' Trans Am are better than a C6 Z06. Would the braking force be atleast somewhat equal to the LS1 calipers compared to the Z06 after having the "appropriate/OE spec" master cylinder bores, boost assist, and pedal ratio etc?

[Ron Sutton]

Hi Scott,

My concern is you're coming to a conclusion about braking systems, looking only at one part of the system ... the caliper piston area. Frankly, that's why many brake & pad manufacturers don't release specs. They're concerned a little information ... without the whole picture ... can lead to bad brake choices & incorrectly operating brake systems.

Originally Posted by 67goatman455

I'm still completely baffled that the brakes on my 99' Trans Am are better than a C6 Z06.
That's not accurate. Just the piston size on the calipers are smaller in the C6 Z06. But the pedal ratio, rotor diameter, brake compound all make the total C6 Z06 brake package have slightly more braking force than the '99 Trans Am.

Would the braking force be at least somewhat equal to the LS1 calipers compared to the Z06 after having the "appropriate/OE spec" master cylinder bores, boost assist, and pedal ratio etc?

As covered above, the C6 Z06 Brake system has slightly more braking force than the '99 Trans Am. The GM engineers just got there another route than caliper piston area.