Manual Brake System Trouble Shooting: Expected Line Pressure?

[FETorino]

Originally Posted by Ron Sutton

Hey Josh,



You don't need 16" rotors. I have designed brake systems with 5500# total braking torque utilizing 11-3/4" rotors front & rear. The main reason to increase rotor size is to increase the thermal capacity of the rotors to survive long races.

I never run a rotor larger than needed, because the rotational weight KILLS performance. It adds to unsprung weight ... making the suspensions job of controlling that wheel harder. And it adds to the rotating weight. Not only is the rotor heavier ... but you're moving it out on a bigger radius.

I cringe when I see guys spend $1200 a wheel to shave 2-4# off ... then add rotors that weigh 6-8# more.

I learned long ago, if we cool the rotor properly, we can run a little less mass in the rotor ... so it's lighter. For this advantage ... I make cooling the rotors a priority.



[/COLOR]

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.

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?

.

Technical questions for Flash, this should be good.

[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?

[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?