Name these Brakes??

[toddz69]

Hey that was suposed to read not done. Im very interested in the upgrade and keeping my 15" wheels. I should have read it before I hit send Sorry. This sounds like it could be an easy upgrade to factory discs. In one of the past issues of BD there was a guy who used cobra brakes but you have to use 17" wheels. still trying to find out how he did the cobra setup.

I helped do some testing with the Cobra calipers/17" wheels setup earlier this year. One of the Bronco vendors should be releasing the kit soon.

Todd Z.

 

[Bronco Biff]

Not that the brakes have not been extremely interesting, and not wanting to hijack... but I'm wondering what the history of this parts bronco is.....Looking at the paint scheme, body damage, and the apparent vintage of the upgrades, I wonder if this is a retired racer?

 

[chuck]

The pressure loading on the pad has always been a big question for me because I totally agree with your analysis stated above. I was re-reading a chapter in James Walker's "High Performance Brake Systems" book a few weeks ago and he mentioned the notion of matching or increasing the piston area sizes when considering any caliper upgrades. Considering how multi-piston calipers apply more uniform pressure on the pads and other good things about their design, I've always wondered if there was some % factor that could be applied when determining equivalent pressure/loading values for the multi-piston calipers, i.e. if we look at the pad size and loading of a multi-piston caliper and determine we could reduce the effective piston area of the multi-piston caliper by 15-20%? simply because we know the force is more evenly distributed. Who knows - I know we're splitting hairs :-* .

And I would like to see more of the mounting bracketry for these calipers even if I don't want to run them myself. It could give me some ideas for other models.

Todd Z.

Brakes are all about PSI so couldn't you calculate the square inches of each piston x the number of pistons 4 to get the total area of piston x the brake pressure for a 4 piston caliper? Then compair that with the area on a 1 piston caliper x 2? I think the pressure would be x2 on the one piston caliper because the same pressure would be on both sides of the caliper because of the slid. Also, brake systems need to be balanced so when you add brake to the front you also need to add brake to the rear and more than lock up is unuseable.

 

[Broncobowsher]

Brakes are all about PSI so couldn't you calculate the square inches of each piston x the number of pistons 4 to get the total area of piston x the brake pressure for a 4 piston caliper? Then compair that with the area on a 1 piston caliper x 2? I think the pressure would be x2 on the one piston caliper because the same pressure would be on both sides of the caliper because of the slid.

That is how I understand brake systems as well.

The single piston tends to throw people as they only look at it as a single force, the one on the piston. On a fixed caliper mount (typical 4 piston caliper with opposed pistons this is true. the mount is fixed and the pistons reaction is single acting. the reaction of the case is canceled by the pistons on the other side.
Single piston floating calipers have a reaction force. since the caliper wraps around the rotor the reaction force is the same as the pistons force. To counter that the piston in a floating caliper moves twice as far in it's bore as a piston in a fixed caliper. the force to apply the pressure is the same, but since the caliper floats you have 2 pads to squeeze per piston instead of 1 pad. Basicly a floating caliper design gets a free fake piston without the extra work of more bores, pistons and seals, but the caliper need to float on pins and not be fixed.

 

[Rlemon]

Hey chuck I emailed greasball at BD about the 8-08 feature bronco that had a cobra front caliper setup. He replied that he to was interested but was unable to make contact with the owner. Greasball said that you might have info on this setup. I have a 76 with factory brake system but with 35 toyo would like to do a complete brake upgrade. I have been told in the past that multi piston calipers could be better upgrade as you get more brake preasure on the smaller piston from the same amount of force applied?. I am in the medical buisness and this makes sence to me. A smaller bore syringe as apposed to large bore can do lots of damage due the increase in preasure and velocity of the fluid with the same amount of force applied. I may be comparing apples and oranges what do you Guys think?.

 

[toddz69]

Hey chuck I emailed greasball at BD about the 8-08 feature bronco that had a cobra front caliper setup. He replied that he to was interested but was unable to make contact with the owner.

If you're referring to Gary Yorston's Bronco, which was on the cover of BD, I might be able to answer some questions you might have regarding his Cobra brakes.

Todd Z.

 

[chuck]

Brake pressure is measured in PSI. Just to get the idea without the math lets say that everything is square. The M/C is 1" square and caliper piston is 1" square. If you apply 100 PSI to the M/C piston it would apply 100 PSI to the caliper piston but if you apply 100 PSI to the M/C and the caliper is 4" square you would be applying 400 PSI to the caliper piston. That is how you get more or less braking in the front or rear brakes with the same M/C. Read balanced brakes. I think the opposite is true of a syringe. The PSI would be much more on the fluid side of a small syringe than on a large one for the above reason.

 

[chuck]

Hey chuck I emailed greasball at BD about the 8-08 feature bronco that had a cobra front caliper setup. He replied that he to was interested but was unable to make contact with the owner. Greasball said that you might have info on this setup. I have a 76 with factory brake system but with 35 toyo would like to do a complete brake upgrade. I have been told in the past that multi piston calipers could be better upgrade as you get more brake preasure on the smaller piston from the same amount of force applied?. I am in the medical buisness and this makes sence to me. A smaller bore syringe as apposed to large bore can do lots of damage due the increase in preasure and velocity of the fluid with the same amount of force applied. I may be comparing apples and oranges what do you Guys think?.

I don't look at Gary's stuff as I don't want anyone to think I stole his idea

 

[Rlemon]

If you're referring to Gary Yorston's Bronco, which was on the cover of BD, I might be able to answer some questions you might have regarding his Cobra brakes.

Todd Z.

Hi Todd Z I don't have the issue with me but I believe it is. I am looking for a poss brake upgrade and would like to know what the parts are sourced from or are they custom. I think the caliper is a common part but would like to know more about the rotor and hat and caliper bracket. Greasball at BD was also looking for more details.

 

[Rlemon]

Brake pressure is measured in PSI. Just to get the idea without the math lets say that everything is square. The M/C is 1" square and caliper piston is 1" square. If you apply 100 PSI to the M/C piston it would apply 100 PSI to the caliper piston but if you apply 100 PSI to the M/C and the caliper is 4" square you would be applying 400 PSI to the caliper piston. That is how you get more or less braking in the front or rear brakes with the same M/C. Read balanced brakes. I think the opposite is true of a syringe. The PSI would be much more on the fluid side of a small syringe than on a large one for the above reason.

Chuck thanks for the reply. This description makes more sense than mine I was trying to compare apples and oranges. Still looking for a better brake upgrade for future project.

 

[chuck]

I havn't done the math but I think that the T-bird calipers will apply more brake pressure than the 4 piston calipers can. Brake pressure is not the only thing that makes good brakes though so the 4 piston calipers may be better for other reasons like maybe the 4P calipers may use bigger pads?better cooling or other things I don't know enough about the 4P calipers to say for sure but I do know that the T-bird calipers will make 37" tires stop turning suddenly and they are very dependable.

 

[Rlemon]

I havn't done the math but I think that the T-bird calipers will apply more brake pressure than the 4 piston calipers can. Brake pressure is not the only thing that makes good brakes though so the 4 piston calipers may be better for other reasons like maybe the 4P calipers may use bigger pads?better cooling or other things I don't know enough about the 4P calipers to say for sure but I do know that the T-bird calipers will make 37" tires stop turning suddenly and they are very dependable.

My brakes are stock 76 and were pretty good till I changed from 33"to 35" toy's. These are much bigger and heavier than the old BFG. Now I get pretty good brake fade and a longer stopping distance. A friend also told me about these. Sound like these caliper will get me back in the wright direction till I can do a major upgrade thanks.

 

[toddz69]

Hi Todd Z I don't have the issue with me but I believe it is. I am looking for a poss brake upgrade and would like to know what the parts are sourced from or are they custom. I think the caliper is a common part but would like to know more about the rotor and hat and caliper bracket. Greasball at BD was also looking for more details.

Calipers are common late model Mustang Cobra/PBR two piston calipers. Everything else is custom.

Todd Z.

 

[toddz69]

I havn't done the math but I think that the T-bird calipers will apply more brake pressure than the 4 piston calipers can. Brake pressure is not the only thing that makes good brakes though so the 4 piston calipers may be better for other reasons like maybe the 4P calipers may use bigger pads?better cooling or other things I don't know enough about the 4P calipers to say for sure but I do know that the T-bird calipers will make 37" tires stop turning suddenly and they are very dependable.

Yes, the T-Bird calipers' pistons are large enough that they apply more force than any of the 4 and 6 piston calipers I'm familiar with.

Hopefully Apogee will chime in and school us on the merits of multi-piston calipers as this is an area of his expertise.

Todd Z.

 

[BwoncoHowie]

Brake pressure is measured in PSI. Just to get the idea without the math lets say that everything is square. The M/C is 1" square and caliper piston is 1" square. If you apply 100 PSI to the M/C piston it would apply 100 PSI to the caliper piston but if you apply 100 PSI to the M/C and the caliper is 4" square you would be applying 400 PSI to the caliper piston. That is how you get more or less braking in the front or rear brakes with the same M/C. Read balanced brakes. I think the opposite is true of a syringe. The PSI would be much more on the fluid side of a small syringe than on a large one for the above reason.

The t-bird rotors are a full 12" in diameter, so you can throw that factor into the math mix too.

The t-bird disc is over an inch thick as well so it can deal with heat pretty well i would think.

 

[chuck]

The t-bird rotors are a full 12" in diameter, so you can throw that factor into the math mix too.

The t-bird disc is over an inch thick as well so it can deal with heat pretty well i would think.

The T-bird calipers would be on the EB rotors