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ive wondered.. why hasnt anyone done a dual caliper brake setup.. two calipers per rotor.. one directly across from the other. i think this would be really cool to do. what would it take to fabricate besides the caliper brackets?
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I think it's due to heat build-up that would occur. You would be putting a lot force onto the rotor building up heat on it and in the pads while taking away surface area it use to have to cool.
Not to mention there really isn't a point with all the upgrades available. The calipers aren't really the source of the problem it's the rotors. That's why everyone usually ditches the 10.5s for the 1LE, LS1, Baer, C4... etc upgrades. Other reason for such upgrades would be get a caliper with more pistons for more evenly displaced pressure.
Last edited by fireturd350; 03-29-2005 at 02:32 AM.
ok now this is kinda exotic, nothing i would try to do, but what if thier were two rotors per wheel. with a single caliper on each? that would be crazy cool.
You'll run into issues with spacing. If you go back and review some of the older posts about C5 brakes I think ede mentioned something about how he wasn't to interested in a C5 setup due to the fact it would have to come off the spindle more than a C4 or similar upgrade. Which in turn there isn't that much room and major changes would have to happen.
If done you would have to either customize a complete system if even possible.
Then you would still be limited to a very narrow rim. I highly doubt a 7" width would even fit, unless you found some way to have enough clearance on the inside of the rim to sit around the brake assembly. The spacing taken up by the 2nd rotor and caliper have to come from somewhere. Good luck on finding long enough wheel studs too.
What would be the point? Friction is proportionate to pressure and the 2 materieals that are being rubbed together, surface area has nothing to do with it. Basically you’d end up with a heavier, more complicated and less functional setup (more of the rotor would be covered at any particular time preventing cooling)
No, again, surface area has NOTHING to do with friction. Open a physics book
The only way that there would be any merit in it is if you had a HUGE rotor with tons of airflow (like on a motorcycle) and tiny calipers and then you could theoretically spread the force more evenly over the disk which would allow you to decrease the disks structure some saving weight, but it would be difficult to design 2 or more calipers and mounting brackets that would weigh less then the amount of weight saved at the rotor.
Originally posted by 83 Crossfire TA No, again, surface area has NOTHING to do with friction. Open a physics book
The only way that there would be any merit in it is if you had a HUGE rotor with tons of airflow (like on a motorcycle) and tiny calipers and then you could theoretically spread the force more evenly over the disk which would allow you to decrease the disks structure some saving weight, but it would be difficult to design 2 or more calipers and mounting brackets that would weigh less then the amount of weight saved at the rotor.
bs, and im not going to bother posting why since you'll just argue.
bs, and im not going to bother posting why since you'll just argue.
u = Fr / Fn.
there is no part of the equition for surface area.
The friction is determined by the force, not the surface area. The force is determined by presure x area. So as the area increases, the pressure decresases, give you the same force. I can't explain this well, online, in person I would do a much better job.
So if you displace X amount of fluid, over a piston area of Y (forcer = pressure x area) which is constant, regardless of pad size. the coeffeciant of friction, remains the same regardless of pad size.
NOTE: this is from the physics stand point. Larger pad size does have advantages, with pad wear, and heat disipation. I agree that a larger pad is a better choice. But that is not because of there is more friction. In a braking system, there is SO much more at work than just the friction.
So I guess I will say you are both right. 83 is correct, the friction doesn't change (remeber 8th grade physics class, and draging a block of wood across the table, given the same mass (mass and gravity give you the force) the surface area made no change in the friction.
EDIT.... I found someone who discribes it better than myself.
Quote:
Although a larger area of contact between two surfaces would create a larger source of frictional forces, it also reduces the pressure between the two surfaces for a given force holding them together. Since pressure equals force divided by the area of contact, it works out that the increase in friction generating area is exactly offset by the reduction in pressure; the resulting frictional forces, then, are dependent only on the frictional coefficient of the materials and the FORCE holding them together.
there is no part of the equition for surface area.
The friction is determined by the force, not the surface area. The force is determined by presure x area. So as the area increases, the pressure decresases, give you the same force. I can't explain this well, online, in person I would do a much better job.
So if you displace X amount of fluid, over a piston area of Y (forcer = pressure x area) which is constant, regardless of pad size. the coeffeciant of friction, remains the same regardless of pad size.
NOTE: this is from the physics stand point. Larger pad size does have advantages, with pad wear, and heat disipation. I agree that a larger pad is a better choice. But that is not because of there is more friction. In a braking system, there is SO much more at work than just the friction.
So I guess I will say you are both right. 83 is correct, the friction doesn't change (remeber 8th grade physics class, and draging a block of wood across the table, given the same mass (mass and gravity give you the force) the surface area made no change in the friction.
EDIT.... I found someone who discribes it better than myself.
lets just set all book physics aside, and work on the application at hand..
regardless of the actual friction formula (that i agree with), theres the APPLICATION of it to brakes.... and theres more to it then u = Fr / Fn
yes there is, but it doesn't have to do with braking forces. The application side of this, is with the larger pad area, you can increase the force and to yeild the same pressure per unit of area the same as before, which will give you more stopping power. But you have ot increase force, which means a larger MC. that is properly matched the total piston area of all the calipers.
Now lets talke about how you can really apply this. You can't, because you will overcome the the tires long before the rest of this becomes a factor. You will also heat soak the rotor, long before the gains of the dual caliper would be noticed. Beyond the bling and oohhh-awwww factor, there is not applicable gain to be had.
Yes, more brake pad area would extend the life of the pad, assuming the same compound but more pad area would also require a different compound to reach operating temp/work correctly…, but again, it will not effect stopping force.
the fact is that if it wasn't for heat there would be on reason to even go with the bigass rotors that are so popular with now..
Or build your dual caliper brakes and prove the rest of us wrong… I’ll waste my time on something else.
Originally posted by Dewey316 yes there is, but it doesn't have to do with braking forces. The application side of this, is with the larger pad area, you can increase the force and to yeild the same pressure per unit of area the same as before, which will give you more stopping power. But you have ot increase force, which means a larger MC. that is properly matched the total piston area of all the calipers.
Now lets talke about how you can really apply this. You can't, because you will overcome the the tires long before the rest of this becomes a factor. You will also heat soak the rotor, long before the gains of the dual caliper would be noticed. Beyond the bling and oohhh-awwww factor, there is not applicable gain to be had.
obviously the dual caliper idea is way overkill in stupid... i just hate when he oversimplifies things and applys book math to somthing that is more indepth in the real world.
The whole system wold be one of those show factors, but practicality plays an issue. Why not go with six piston calipers at the front and four piston calipers at the rear. I'm not sure about clearancing issues or wheel sizes. I don't even know if they make a six piston caliper kit.
Actually, the dual caliper per rotor set-up is nothing new. It is quite common on dragsters, and specific kits are made by several of the aftermarket brake manufacturers:
Dragsters mainly use them since they only have rear brakes, and need to stop very quickly from high speeds in a short distance (but only once at a time), plus their vehicles are extremely light. I have seen this set-up on the rear of some heavy full bodied cars, but again, only in a drag race only type application.
Not to start the argument again, but with two calipers wouldn't you have twice the piston area? wouldn't this create twice the force with the same brake line pressure? It is not the same as just increasing the surface area, you are adding a second force to that increased area.
That argument would only be valid if someone asked if they could double the size of their pads in their caliper, without changing the size or quantity of their caliper pistons,
Originally posted by Dewey316 you don't have the same force on the pistons, you have half the force. because the force frome MC is spread over a larger piston area.
This is not correct. Research basic hydraulic principles. If you put two of the same calipers on a given rotor, you will have the same hydraulic pressure applied to each caliper, but you will double the clamping piston area (force) on the rotor. It seems that some people are confusing total piston area with total pad area.
not that you couldn't do that with a larger piston or multiple piston calipers.
FWIW, what makes sense in a drag race situation where you have to stop once and then get a cool down and only do it a couple of hundred times a year is vastly different to what you do on the street or road course.
In the later days of the of the old IMSA series. The by then aging porsche 962s were uncompetative. The wide layout of the flat 6s and twin turbos really cut into the ground effect tunnels. One of the things tried were dual calipar setups. The conclusion; they provided better initiall bite and more constant braking action but were hell on rotors, overheating and heat checking ectra. The idea was abandond by the middle of the next season.
Originally posted by firehawkslplus In the later days of the of the old IMSA series. The by then aging porsche 962s were uncompetative. The wide layout of the flat 6s and twin turbos really cut into the ground effect tunnels. One of the things tried were dual calipar setups. The conclusion; they provided better initiall bite and more constant braking action but were hell on rotors, overheating and heat checking ectra. The idea was abandond by the middle of the next season.
Porshce was running a full circular pad brake set up in their GT car this year (maybe it was last year). Not sure how many pistons it had, but it was one HUGE caliper surrounding the whole rotor.
Originally posted by miacamaro305 true i actually saw a benz at the auto show that had dual calipers in the rear but one was a bit bigger then the other
The Viper also had this. When I asked the Dodge reps about it, they told me just as I had figured. The larger was the actual braking caliper, and the smaller was the E-brake.
Originally posted by bnoon Porshce was running a full circular pad brake set up in their GT car this year (maybe it was last year). Not sure how many pistons it had, but it was one HUGE caliper surrounding the whole rotor.
Carbon fiber is a wonderful thing. I think that's a carbon on carbon setup i.e. both pads and rotors. Can you say cubic money!!