I really recommend upgraded brakes and new tires

[Pablo]

i'll put my 2 cents in here also.


if you have a slotted rotor VS a non-slotted rotor/drilled rotor whatever.

yes you do lose the amount of surface area on the face of the rotor but you actally add more pressure to surface area when going to a slotted/drilled rotor. to do the same stopping power.


say for example your brake pad has A surface area of 6 inches. so your non slotted/drilled rotor has the same 6 inch pad applying pressure @ say 30 psi

so you have 30 psi over 6 inches thats 5 psi per inch when you allpied the brakes.

with the same pad @ 6 inches of surface area but with a drilled rotor you have now reduced the surface area that the brake pad comes in contact with.

so the new contact area on the rotor is ruduced down to 4.5 inches on the rotor witht he same 6 inch pad. so it's like have a 4.5 inch pad correct?

so now your applying 30 psi to the 4.5 surface area and you get 6.667 psi of clamping pressure inturn more pressure @ the same brake caliper/pad combo.

look at the racing clutches of stick cars and you will see that they have reduced the surface area on the friction disc for that same reason that i have explaned up above.

But like someone said up above there is a problem with the heat build up with the massnot being there for the heat soak your gonna run into brake fade alot faster.

brake fading is boiling the brake fluid in the caliper from what i have read. Fluid fade
Fluid fade is caused by the boiling of the brake fluid in the calipers. This produces bubbles in the brake system. Since bubbles are compressible, this makes for a soft spongy pedal. In worse cases, the pedal can plunge to the floor with very little slowing! Fluid fade can be avoided by running a high grade racing type brake fluid and/or frequent changes of brake fluid. Also if you change the pads before they get super thin, the remaining friction material will help insulate the calipers from the heat. Some people have had some success with having swaintech spray thermal barrier coating on the backing plate of the pads to help isolate the heat but I have never tried this.

Fluid fade usually has a gradual onset.



HTH

Flame suit on

You dont increase braking force by reducing the area, sliding friction remains the same regardless of area. The only thing that matters is the amount of force applied to the objects sliding against eachother. The one caveat to this is any adhesive qualities (as I currently understand it) the materials being rubbed together might have. If they do, then the surface area matters. The smaller the surface area the less the adhesive quality plays into the equation. Granted, the increased psi might play into increasing the adhesive quality of the pad now that I think about it. It might end up being a wash depending on the system.
I do however know that many aftermarket direct replacement brake systems in modern cars that have no problem with brake modulation and generating enough force to skid the tires fail to produce results as good or much less better than stock in 1 time brake tests.

When it comes to braking force, its not how many psi on the swept area of the rotor/brake pad face that counts, its how many lbs of torque they are scrubbing off at the hub.

 

[madhat]

I can't imagine for the life of me how drilling rotors=more clamping force(you apply the same force over less area=less force)...less frictional space=less friction. Someone needs to make a calculator(maybe Bremo or someone that could profit from it, therefore putting more effort into it) that takes into account tires size, weight, rotor size, pad size, etc...

 

[Pablo]

I can't imagine for the life of me how drilling rotors=more clamping force(you apply the same force over less area=less force)...less frictional space=less friction. Someone needs to make a calculator(maybe Bremo or someone that could profit from it, therefore putting more effort into it) that takes into account tires size, weight, rotor size, pad size, etc...

I dont think they would do that. All that would do is show that nothing you do short of modifying your power booster will change the ratio of input force to output force slowing you down. Those brake systems are for improved heat dissipation and modulation. If you can lock up your tires with stock brakes, what more force do you need? its not going to help. The only thing that will help is if you can repeatedly generate the force necessary to stop you, and modulate it easily

I'm no brake guru so if someone out there is, please feel free to correct me if i am wrong. It seems like pretty simple math to me.

 

[turbov6joe]

Drilled/Slotted rotors help dissapate the gasses that build up under the pads that cause the pads to float on the rotor surface.

 

[Pablo]

Drilled/Slotted rotors help dissapate the gasses that build up under the pads that cause the pads to float on the rotor surface.

this was discussed above

 

[Turtle TR]

The formula 1 brake picture is one of those carbon rotors with ceramic compound pads. The take heat very well, more so, they also help reduce the parisitic force within the rotating mass making braking easier and easier to modulate steering. Most people cant afford that technology on street cars...and they need a lot of heating to get them to work properly, garnering them pretty useless on street cars.

the best way to utilize brakes to it's fullest potential and predictablilityh are braided s.s. lines (probably one of the better investments), better metallic brake compounds, stickier tires and, lesser weight on the car. I'm sure there are tons of aftermarket fiberglass panels that can replace the stock sheet metal that will greatly reduce the mass. And unless you guys plan on tracking or auto-x'ing the TR or TTA, changing out your brake fluid with higher boiling point is pretty useless.

most track day goers (myself included) would prefer slotted over x-drilled. it is said that x-drilled are more prone to cracking. While I have cracked a couple of slottled rotors myself..I've cracked more x-drilled. The more prefered choice is solid rotors because they have better surface contact. while slotted is the closest to being solid...it's best suited for better pad wear - where the slots rather "wipe" the pad's surface vs expelling gasses. better pad compounds emit less gasses. the downside of both rotors is increased pad wear altogether. but thats the price you pay for performance.

larger rotor sizes are mainly for reducing brake fade...you will not necessarily get better stopping distance. The same goes with larger pad surface. In some cases, it may do more harm than good in your quest for shorter stopping distance. With larger rotors, you need matching calipers. larger calipers with more pistons just create a more evenly distributed clamping force.

more about using larger rotors and using stock calipers here:
http://www.stoptech.com/tech_info/StopTech White Paper A7-Caliper Move-Out Kits.pdf

Of course there are more physical factors...but thats the gist of it. you dont need math to figure things out unless you're a fabricator or engineer. Just a little common sense to know what works and what doesnt...and not to follow the trends too far (ie. large rotors).

There's more info on brakes on StopTech.com too for more reading. Too bad they dont have anything off the shelf for GN's. If there's generated interest, they could probably make something.