Anyone have any Brake Questions?

[OG_Racing]

I have a set of Baer 6S front calipers with 14" rotors that I want to use on my 68 Camaro. I have a 9" rear that has the new style ford ends. (Non floater obviously) and have been looking for a floating rear caliper. Will the wilwood D154 setup with a piston area of 4.12 work for the rear with my front brakes?
My front calipers have 1.62,1.37, and 1.18 Pistons. My car has a 7/8 manual wilwood master on it now.

http://www.wilwood.com/Calipers/Cali...ston%20Floater

Thanks!

Hello Hugger,
What size rear rotors are you planning on running?

[Hugger67RSSS]

12.19" rear rotors

[OG_Racing]

hugger,
What pedal ratio are you using? i'm having a hard time reccomending master cylinders for you. looks like the 7/8's is not going to work.

[Hugger67RSSS]

Stock pedals with the master bolted to the top hole, I've always thought that made it 6:1 but I could be wrong. Is there another rear brake kit you would recommend with the fronts that is a floating caliper that would help alleviate my pad knock back instead of the wilwood kit? Baer does not make a floating caliper that I'm aware of.

Thanks again

[OG_Racing]

Stock pedals with the master bolted to the top hole, I've always thought that made it 6:1 but I could be wrong. Is there another rear brake kit you would recommend with the fronts that is a floating caliper that would help alleviate my pad knock back instead of the wilwood kit? Baer does not make a floating caliper that I'm aware of.

Thanks again

here is the problem i'm having. in order for you to keep your Pedal pressure under 100lbs with those calipers you'll need 1/2" master cylinder. the smaller the MC the more you'll need to travel. with a .5" mc you'll need 70" of pedal travel or with the current MC you'll need to press 250lbs of force to get your system to 1200psi. i think your going to need a booster to get there. I haven't even started on brake balance of the braking system yet, but the front pistons are so small and the rotors are huge. i'm not sure if i can find a floating system that can match it off the shelf.


your going to want to run a booster with that set up.
can you do this?

[Hugger67RSSS]

My motor doesn't produce a ton of vacuum, haven't checked it but I'm sure it's pretty low. I'm curious as to why you say the Pistons are so small? Baer recommends a 7/8 master but that is with their setup on the rear also. Glad I asked the question now.
Would I be better if keeping the C6 Z06 brakes on the car? They work good but having knock back issues.
Thanks

[71RS/SS396]

Stock pedals with the master bolted to the top hole, I've always thought that made it 6:1 but I could be wrong. Is there another rear brake kit you would recommend with the fronts that is a floating caliper that would help alleviate my pad knock back instead of the wilwood kit? Baer does not make a floating caliper that I'm aware of.

Thanks again

I believe Baer is now making a floating caliper to match your front brakes. I'm pretty sure Tom Farrington (tommycomfort) has them on his 66 Chevelle.

[OG_Racing]

My motor doesn't produce a ton of vacuum, haven't checked it but I'm sure it's pretty low. I'm curious as to why you say the Pistons are so small? Baer recommends a 7/8 master but that is with their setup on the rear also. Glad I asked the question now.
Would I be better if keeping the C6 Z06 brakes on the car? They work good but having knock back issues.
Thanks

tell me about what your car is doing. the answer might be better then a whole new kit. try to include all the details.

[Hugger67RSSS]

The car has about 700 miles on it now, normal street driving the brakes work perfect. I can achieve lockup with enough pedal pressure.
I took the car to a couple local scca autocross days and will lose about half of the pedal after hard corners. If I pump it once or twice quickly they are instantly back to normal. It is bad enough that I didn't want to take it to the indianapolis good guys and not feel comfortable with it. They have been bled a couple times since installed and haven't gotten out anymore air.
All of this with 7/8 wilwood master and front and rear C6 Z06 brakes. Non floating rear axle.

Thanks!

[Hugger67RSSS]

Stock pedals with the master bolted to the top hole, I've always thought that made it 6:1 but I could be wrong. Is there another rear brake kit you would recommend with the fronts that is a floating caliper that would help alleviate my pad knock back instead of the wilwood kit? Baer does not make a floating caliper that I'm aware of.

Thanks again

I believe Baer is now making a floating caliper to match your front brakes. I'm pretty sure Tom Farrington (tommycomfort) has them on his 66 Chevelle.

Thanks Tim,
I will call Baer or PM Tom since he is local to me.

[OG_Racing]

The car has about 700 miles on it now, normal street driving the brakes work perfect. I can achieve lockup with enough pedal pressure.
I took the car to a couple local scca autocross days and will lose about half of the pedal after hard corners. If I pump it once or twice quickly they are instantly back to normal. It is bad enough that I didn't want to take it to the indianapolis good guys and not feel comfortable with it. They have been bled a couple times since installed and haven't gotten out anymore air.
All of this with 7/8 wilwood master and front and rear C6 Z06 brakes. Non floating rear axle.

Thanks!

sounds like your right it is pad knock back. i would install the z51 brakes in the rear. use a kore 3 kit, or convert your axle to a full floating axle.

[Hugger67RSSS]

The car has about 700 miles on it now, normal street driving the brakes work perfect. I can achieve lockup with enough pedal pressure.
I took the car to a couple local scca autocross days and will lose about half of the pedal after hard corners. If I pump it once or twice quickly they are instantly back to normal. It is bad enough that I didn't want to take it to the indianapolis good guys and not feel comfortable with it. They have been bled a couple times since installed and haven't gotten out anymore air.
All of this with 7/8 wilwood master and front and rear C6 Z06 brakes. Non floating rear axle.

Thanks!

sounds like your right it is pad knock back. i would install the z51 brakes in the rear. use a kore 3 kit, or convert your axle to a full floating axle.

I already have the set of 6S Baer front brakes, nothing will work with those in the rear so I can sell my Z06 brakes as a set of 4?
Thanks

[OG_Racing]

any other questions?

[andrewb70]

any other questions?

What do I do with a car that will be drag strip oriented and has skinny front tires and larger rear tires?

Andrew

[OG_Racing]

What do I do with a car that will be drag strip oriented and has skinny front tires and larger rear tires?

Andrew

haha get more front tire :P

you don't need brakes for drag racing

[andrewb70]

haha get more front tire :P

you don't need brakes for drag racing

Well, you need some brakes, especially on the street. I've seen some drag cars actually put a prop valve on the front brakes. Is that legit?

Some solid advice would be appreciated. The internet is full of "information."

Andrew

[OG_Racing]

Well, you need some brakes, especially on the street. I've seen some drag cars actually put a prop valve on the front brakes. Is that legit?

Some solid advice would be appreciated. The internet is full of "information."

Andrew

Oh sorry i thought you where joking.

I wouldn't bias the front brakes unless i was building a Dirt car. Drit cars will shut off the front brakes in order to use the rear brakes to slide the car into the corner. Mind you they are doing this at 70-110mph



Tire, tire, tire.. Stopping is all about the tire. allow me to steal a quote from the first page.

Most people think that the main thing you need in a (brake) system is TQ (brake Torque or High mu). HIGH TQ is all i hear. That couldn't be further from the truth. Braking Tq and horsepower couldn't be anymore different. Don't think that More Brake Tq is good like more Horsepower is good. When I give classes start off asking the Question "What stops the car?". 9/10 i get an answer of "the brakes" to that I reply with "WRONG, the tire stops the car." if you have a car that hit the Curbing on a racetrack and two tires are airborn, how much traction does that car have? how will it be able to stop with 2 tires in the air? the answers are, traction is less than 50% of having 4 tires on the ground and It won't be able to stop. Hitting the brakes with the tires in the air, will just make the wheels stop spinning, and that car's speed won't be decreased. Remember in a braking system "more" is not better, it's just more. ..... what we are trying to do is engineer a complete a braking package that fits a chassis application.....

On a street/strip car you’re playing a game. Your trading traction for rolling resistance. On the strip this makes sense because you don’t need any traction on the front wheels to perform. When that car goes on the street the ability to take a turn and stop is much more important. Now you need front end traction to achieve your goal of safe highway motoring.

The internet’s idea of choking off of the front braking system, This is an attempt to reduce the braking systems ability to lock a small set of front tires. Normally with a set of pizza cutters on a road car, you tap the brakes and the tires just lock up. Anyone that has street driven pizza cutters know what i'm talking about, they also know the car doesn't slow down at all. To fight this lock-up the trend is to bias the system to the rear. What they are doing is balancing the braking system to the tire. what they are not doing is balancing the braking system to the chassis. Allow me to explain..


I worked at PFC when we built the delta wing’s brakes. I like to use this car as an example allot because of how it’s engineering is completely backwards to every other road car and it makes people think.

Drag cars have allot of similar characteristics to the delta wing. Big tire in the back, Small 4" tire up front. Despite this tire combo the delta wing can pull -2.0G’s under braking. This is a huge feat as this chassis has a 1/4 of the down-force a normal prototype car has, but it can achieve the same level of braking. FYI A normal road car is about -.7g to-.9g



the DW brakes are balanced to the chassis. 80% of the weight and down-force on the DW (Delta Wing) is over the rear axle. Physics allows us to put massive rear brakes and tiny front brakes and still achieve very high threshold of breaking.

People who drag race normally don’t have rear heavy cars. I would assume if they are lucky they can get a 50/50 weight split. Due Drag racing's requirements to perform they have a similar tire choice to the DW. In order to have only one set of tires people will bias the brakes to match the tires, they are decreasing the fronts tires ability to lock under breaking. what they don't know is that they are also decreasing braking performance. a small tire with a heavy load will quickly become overloaded. it's load handling capabilities are never going to increase, it is limited. If we follow the internet's lead a car with very heavy rear biased brakes in a panic stop situation would be very dangerous. under breaking the weight in the chassis will pitch forward, and apply more pressure (traction) over the front tires. At this time the weight shift is lifting the load up and off of the rear axle. With a very heavy rear brake bias, the front tires have all of the traction and a small amount of brake bias, and the rear tires have less traction and all of the braking bias. This will cause the rear of the car to rotate. this rotation is what road racers know as trail braking. Do this on a highway exit with a novice driver and you’re going to spin out into a guard rail. the only way to fix this would be to put a tire on the front axle that can handle the additional load.


My suggestion: instead of biasing your brakes to the rear, is to bring your racing tires to the track. load them up on a little trailer, Switch back over to your normal sized tires for the road home.


Best Regards,
Johnny C.

South East Field Representative
Office: 1-800-934-9112 ext 124
Direct: (770)-880-7579

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[andrewb70]

Johnny,

That all makes sense...Thanks.

Andrew

[mlogdog]

Got a Question? Just started a tear down of a 66 GTO Convertible I'm putting in a Zl1 lsa motor in and i can get a set of CTS-V 2012 Brembo Brakes cheap. Is there a conversion kit to retro fit these.

[OG_Racing]

Got a Question? Just started a tear down of a 66 GTO Convertible I'm putting in a Zl1 lsa motor in and i can get a set of CTS-V 2012 Brembo Brakes cheap. Is there a conversion kit to retro fit these.

Contact tobin at Kore 3. he's the one i contact to make brackets for my PFC kits.