Topic: Brakes- daily driver vs hard driving vs racing

[LatinVenom]

The problem that a lot of folks forget is the tire.
The tire patch and how good the tire is, will make a difference in the way the car stops.
My brakes are stock and unless I use the car on a track(Fade), the stock brakes perform very well with my HIGH PERFORMANCE TIRES.

[wspohn]

Ah, one of the periodic big brake threads (well, slotted brake, anyway).  

The Kappa has a braking system well up to the job on the street.  If you want any improvements, look to improved rubber and a different pad material.  If you like the look of slotted rotors, go for it. Not the ones that reduce surface area seriously because they have so many slots - useless.  I'd stay away from drilled - potential stress fractures from the holes.

As for needing big brakes - not for performance, you don't, not on the street.  Buy them if you must for looks, and don't pretedn that you needed them for safety.

Most people have absolutely no idea what extreme brake use is - and that is appropriate if they just drive on the street.  Take the car on the track and brake from 130 MPH to 30 MPH once a minute for half an hour, with a half dozen other lesser braking events in between, and you will really test the limits of a braking system. And even that sort of test doesn't require big brakes, it just requires appropriate pads and some attention to getting cooling air in there.

[G8TR]

I just bought a setup from DDM. More fir looks, but wanted the slots to disapate the rains here. They can make stopping a chore at times.

[Critterman]

I have been running the DDM kit for over a year, look good and stops great in all weather that I drive in.  With the stickier tires and bigger brakes, as I said earlier I don't get much abs action on heavy braking, the car just slows down very quickly, in a panic stop when I am standing on the brakes and pulling on the steering wheel saying over and over again

"you stupid SOB what where you thinking?"  they do lock and release and I get stopped a lot sooner than I expected.  I do have to pull the seat out of my butt.  Pucker factor is a B____ch

[Yogi]

I'm with you, GJ!   

[gmtech16450yz]

If your ABS is kicking in less, then your brakes are less effective, all other things being equal.

Jim

ABSOLUTELY! I was waiting for someone to realize that.

OK, here's my .02...

The stock pads in the Kappa's heat up and fade WAY too fast for hard, fast driving. (Which like people have said, most drivers are not even near.) Going to aftermarket pads will help a ton with the brake fade and make it so they'll take a lot more heat. I personally don't think the Kappa's need bigger rotors unless you're going to the track with the car. Even with good tires (not the stock Goodyear garbage) you can get the ABS to kick in on a good hard brake apply up to at least freeway legal speeds. That means the brakes are strong enough for those speeds and that amount of tire traction.

The SURFACE AREA in contact doesn't figure into the equation for friction.

Ummmm, surface area has everything to do with friction. After all, aren't we talking about POUNDS PER SQUARE INCH of force applied by the piston? If you have 100lbs force applied to 10 square inches, that's 10lbs/inch force being applied. If you take that area down to 1 square inch, you now have 100lbs pushing on that area. Yes, the force is still the same, but the friction will be VERY different. Picture sliding down a snow covered hill sitting on a salad bowl vs. sitting on a big saucer, I don't think that salad bowl is going to slide very well. Now get off the salad bowl and let it slide down the hill, hmmm, works better with less force applied. I'm no physics professor, but unless I'm missing something force and area have an effect on friction.

So, imho, if you drive your Kappa hard, get aftermarket pads. If you like how the drilled or slotted rotors look, get them. I personally would be a little leery of pushing aftermarket drilled or slotted rotors hard, I would trust the stockers to not break or crack more than aftermarket, especially some of these Ebay or Chinese cheapies.

[2kwk4u]

Ummmm, surface area has everything to do with friction. After all, aren't we talking about POUNDS PER SQUARE INCH of force applied by the piston? If you have 100lbs force applied to 10 square inches, that's 10lbs/inch force being applied. If you take that area down to 1 square inch, you now have 100lbs pushing on that area. Yes, the force is still the same, but the friction will be VERY different. Picture sliding down a snow covered hill sitting on a salad bowl vs. sitting on a big saucer, I don't think that salad bowl is going to slide very well. Now get off the salad bowl and let it slide down the hill, hmmm, works better with less force applied. I'm no physics professor, but unless I'm missing something force and area have an effect on friction.

So, imho, if you drive your Kappa hard, get aftermarket pads. If you like how the drilled or slotted rotors look, get them. I personally would be a little leery of pushing aftermarket drilled or slotted rotors hard, I would trust the stockers to not break or crack more than aftermarket, especially some of these Ebay or Chinese cheapies.

http://www.school-for-champions.com/science/friction_equation.htm

(excerpt from page linked above)
Independent of area for sliding hard surfaces

An interesting result of this equation is that in the case of sliding friction of hard surfaces, the friction is independent of the area of the surfaces. In other words, it is just as difficult to move a 1 square-cm object as a 1 square-meter object, if they both are pressed to the surface with the same amount of force.

This is not intuitive. You would think that there is more friction when the surfaces are larger, but the friction equation states otherwise. You can verify this fact with experiments.

(end of excerpt)

sorry, dude.  If your salad bowl and big saucer have the same coefficient of friction, they'll both slide just as well until the snow starts to compress and melt underneath them...  That will naturally happen much faster with the salad bowl.  Now, make that hill a slope of hard ice and tell me what results you get...

[kennysabarese]

the ABS kicking in less doesn't mean it's worse because he's changed his tires. stickier tires will not break lose as easily. it's hard to compare if you change tires and brakes at the same time.

[Critterman]

Thank you Kenny, my point exactly.

[gmtech16450yz]

http://www.school-for-champions.com/science/friction_equation.htm

(excerpt from page linked above)
Independent of area for sliding hard surfaces

An interesting result of this equation is that in the case of sliding friction of hard surfaces, the friction is independent of the area of the surfaces. In other words, it is just as difficult to move a 1 square-cm object as a 1 square-meter object, if they both are pressed to the surface with the same amount of force.

This is not intuitive. You would think that there is more friction when the surfaces are larger, but the friction equation states otherwise. You can verify this fact with experiments.

(end of excerpt)

sorry, dude.  If your salad bowl and big saucer have the same coefficient of friction, they'll both slide just as well until the snow starts to compress and melt underneath them...  That will naturally happen much faster with the salad bowl.  Now, make that hill a slope of hard ice and tell me what results you get...

How about we find a nice big snow covered hill, I'll put a thousand dollars at the bottom of it. You can ride a salad bowl and I'll ride a saucer. I think my money would be safe.

I didn't read the link, I'm sure I'm wrong as far as the experts go. Unfortunately real life doesn't always follow the rules. If I put a pencil point down in the palm of my hand, and apply 10lbs force to it, will it hurt? Now if I put, lets say a salad bowl in the palm of my hand and apply the same force, will it hurt more or less? I don't care what they say, area has to have some effect on friction. Maybe it all comes down to the surface itself. In your reply and quote I noticed they're talking about hard surfaces, which I agree would apply to brake rotors and pads. What happens to that equation when you change the surface area? Maybe it's as simple as that and I'm thinking soft materials vs. what we're talking about, hard materials. The other thing I noticed in that quote was "You would think that there is more friction when the surfaces are larger, but the friction equation states otherwise." That's weird, who would think a larger area would have MORE friction? If anything a smaller area would have more friction. And how does this apply to bearings? They're hard surfaces and common practice is making the bearing larger (more surface area) if the loads go higher. Needle bearings can handle more load than ball bearings because of increased surface area correct? How about main bearings? Again, bigger bearing surfaces can handle more load, what am I missing? Have the engineers been wrong all these years?

Again, I did not read the link you posted or surfed the web finding info to back up my theories, I don't have time for that. I didn't mean to start a war either, we don't need to go there. I might be wrong, or we might be thinking about two different things. It's really not that big of a deal, I'm not going to loose any sleep over it.

[gmtech16450yz]

"the ABS kicking in less doesn't mean it's worse because he's changed his tires. stickier tires will not break lose as easily. it's hard to compare if you change tires and brakes at the same time."


Oh and nobody said anything about changing tires, or did I miss that. Sorry if I did. Obviously tires would change the anti-lock results.

[ophidia31]

From the research Ive done from building my own brake kit (4pot 12.19 wilwood components to fit under the stock 16" wheel of a Regal GS) and from over the years of other brake options for my car, the biggest improvement you can make is a larger rotor. Keeping with your stock pads a caliper you will have a noticeable improvement in stopping power. Reason being, the torque is being placed further out on rotation.

Plain, slotted, drilled or both, your best bet is plain rotors. Even better would be plain directional vaned rotors. The best would be solid 2 piece directional vaned.

Slots were brought up in the early days of racing because the pad compounds would out gas and create a barrier between the pad and rotor that greatly decreased the available friction. The slots would remove these gasses and restore full friction to the rotor surface. As mentioned earlier, an easy case for slotted rotors on the street that actually help your braking is during foul weather. The slots would remove any water from the surface of the rotor to give you the best surface possible.

The drilling of rotors was brought into racing when there really wasnt anywhere else to decrease your weight from. Thats all drilling is for. Other than that, your taking metal away from the mass of the rotor which you dont want to do. Decreasing the heat holding capability of your rotors. Unlike the magazines lead you to believe, you dont want cool rotors. You want there to be heat to keep your pads in their operating temperature range. But you also dont want to have crazy hot rotors either. Which is were directional vaning comes into play. They act as a pump to bring cooler air into the rotor without decreasing mass or pad contact area.

Two piece direction vane rotors are the best bet you can have. You get the cooling ability of the vanes plus the added bonus of an aluminum heatsink for the rotor hat. After a hard drive, after not even 5 minutes I am able to grab one of my rotors with a bare hand and not even get burned. They are only warm to the touch.

On to the calipers. In my experience now, you dont need a monoblock multipiston caliper on the street. Do they stop even better and look kick ass. You bet they do. But a typical 2-3 (in ssbc case) piston floating caliper is usually more than enough than anyone would need. The main benefits of a monoblock caliper is 1. Much lighter weight than a floating caliper 2. Amazing pedal feel and modulation and 3. Even and instant pad initiation of the surface of the rotor. Unlike with a floating caliper where you first need to push the brake pedal to move fluid to the piston(s) in the caliper to get the inner pad to contact the rotor then push the pedal further to slide the caliper on its slide pins to move the outer pad into the rotor. I make it sound like alots happening but when youd look at a mono block caliper all you do is push the pedal move the fluid to the pistons and both pads engage at the same time. Cuts down on alot of work that needs to be done.

In the end, would I put a 2 piece rotor with a monoblock caliper on my car for the street? Hell yeah, because it looks cool and can smash your face off the steering wheel if you arent careful. Lol But do you need all of that? Hell no. Like I mentioned earlier. Most people would be happier than a pig in shit with a larger diameter rotor, some nice biting semi metallics and stainless lines for pedal feel. Really, thats anyone needs on the street, but for looks, you cant beat a nice race setup.

[Uranium-238]

This is getting old.

Motorsports is the ultimate medium for testing automotive technologies. It has consistently proven on this forum that while larger rotors/calipers do have advantages, upgrading to racing pads and high temp brake fluid is all that's needed unless you're turing a Kappa into a dedicated race car. I don't know of any autocrossers with upgraded pads/fluid that aren't complaining.

[snaponbob]

Big brakes, std size brakes, stock calipers, multi-piston calipers, stock pads, performance pads, slots, holes, whatever. Not sure, but I may seen only ONE reference to upgrading the DOT 3 to DOT 4. I was getting fade with Hawk pads, and it was the DOT 3. As soon as the change was made, almost all fade was gone. If you don't upgrade the brake fluid, you are missing the single best change that can be done to the brake system.

[gmtech16450yz]

Big brakes, std size brakes, stock calipers, multi-piston calipers, stock pads, performance pads, slots, holes, whatever. Not sure, but I may seen only ONE reference to upgrading the DOT 3 to DOT 4. I was getting fade with Hawk pads, and it was the DOT 3. As soon as the change was made, almost all fade was gone. If you don't upgrade the brake fluid, you are missing the single best change that can be done to the brake system.

Exactly!

On my Sky I put braided lines, Hawk pads, flushed and filled with ATE TYP200 brake fluid and have yet to out drive the brakes. I've laid on them so hard at night you can see sparks coming off the front brakes past the outside mirrors!

[Uranium-238]

After upgrading to ATE superblue the only time I saw fade autocrossing was on a 100 degree day on the 4th and 5th runs. On the street only times I've seen it was after several minutes worth of 80 to 30 mph decelerations. I expect with better pads (I'm still running stock) I wouldn't even see fade in these circumstances.

[snaponbob]

After upgrading to ATE superblue the only time I saw fade autocrossing was on a 100 degree day on the 4th and 5th runs. On the street only times I've seen it was after several minutes worth of 80 to 30 mph decelerations. I expect with better pads (I'm still running stock) I wouldn't even see fade in these circumstances.

Once you have cooked the stock pads to the point where you can get them to fade, they will fade more easily over time. Sort of like r-comps heat cycling to death. Streak has been sitting dormant for over a month, yet when I took it out to drive it, the CarboTech pads worked perfectly the first time I hit the brakes in low thirty temps, and that answered that question I had about them. Far superior to the Hawks, but a) dirtier, and b) harder on the rotors. Totally fair trade off. 

[kennysabarese]

Once you have cooked the stock pads to the point where you can get them to fade, they will fade more easily over time. Sort of like r-comps heat cycling to death. Streak has been sitting dormant for over a month, yet when I took it out to drive it, the CarboTech pads worked perfectly the first time I hit the brakes in low thirty temps, and that answered that question I had about them. Far superior to the Hawks, but a) dirtier, and b) harder on the rotors. Totally fair trade off. 

Ok I'll definitely be considering those CarboTechs then I need to replace my Porterfields next season.

[Uranium-238]

Still haven't decided who to go with. EBC and Porterfield are in the front running, carbotech not so much since last time I looked they were double the price of the other two.

[kennysabarese]

I am happy with the porterfields on the street and they would probably be great for AX, but they are more dusty than the stock pads, so i would probably go with EBC if you care about dust.

Dave @ DDM just recommended me to go with Hawk's I will have to compare over the winter.

If the carbos can be used for both street and circuit i might not mind paying more for them.