Brake Discs: Drilled, Slotted, Both, or Neither?

[mikesil]

people fail to realize that bigger rotors mean more rotating mass, which equates to more power to move the wheels and more power to stop them.

I can't remember where i saw the test article, but they 'upgraded' the brakes on a car and found that the car had like 8 feet FARTHER stopping distance. sure better fade resistance, more clamping power, etc, etc, but what about when you need them to come to a full stop?

i agree that keeping a stock rotor size and going with better lines, fluids, and better pads are the best performance improvement.

[blargonator]

but the pros of a better braking system outweighs (literally <8- ) the cons of a weak system.....but anwyays someone already said if you can lock your tires you should not have to upgrade your brakes right? tires can only handle so much. tires are the most efficient upgrade as we should all know.

[Whisky]

On my car I run Powerstop slotted rotors, Motul 600 fluid, Goodridge SS lines, and Porterfield R4-S pads, all stock sized parts. I have no fade and excellent pedal feel and control, the car brakes equally well at Willow Springs and Buttonwillow. Although I will agree about the Axxis pads, they do have the best cold bite I have found and they are fairly fade-resistant, they also wear absurdly quickly and covered my wheels in brown dust in a matter of a few miles. I have no such problems with the R4-S, but they do take one good stop to really bite well.

I would advise against big brake kits. Higher torque isn't going to help you if you lock your fronts at 20 mph.

Remember, if you put big huge calipers on the front, and the rears are still stock, you have a number of problems, none of which will help you get around a circuit faster. Your master cyl is now too small to properly control fluid pressure at the front pistons. Your bias is also way off now. Since you probably do not have a dual cyl brake setup with a bias-bar, you don't have any good way of adjusting bias. If you must do a Z32 swap, do yourself a favor and swap everything, front, rear, and at the firewall.

Another little pet-peeve I need to set straight... weight transfer is a function of weight, CG location, wheelbase, and track width. The vast majority of weight transfer occurs as a funtion of the leverage created by the difference in height between the CG and the opposite force acting on the tires at the ground level. As a result, the best way to decrease weight transfer is to lower the CG, and the only practical way to do that is to lower the car.

Stiffer springs do not substantially alter weight transfer, as only a small portion of weight transfer can be attributed to the x or y axis movement of the CG. Stiffer springs prevent body roll, and body roll is really only bad because it excessively deflects your suspension.

Ultimately, the tires accelerate, turn, and yes, stop the car. Not the engine, not the suspension, not the brakes.

I also agree that Carroll Smith's books are a must-have if you actually want to know something about racing and race cars.

Just my $.02

[JunpoweR]

blah blah blah

There all good..
I personaly like the slotted ones..
less prone to cracking at the holes.

[nightracer]

blah blah blah

There all good..
I personaly like the slotted ones..
less prone to cracking at the holes.

This is the truth people. The GT cars are all running slotted rotors for a reason..

[GRiDRaceTech]

I would advise against big brake kits. Higher torque isn't going to help you if you lock your fronts at 20 mph... If you must do a Z32 swap, do yourself a favor and swap everything, front, rear, and at the firewall.

Exactly. I see the occasional guy running crapper tires with a BBK, expecting to stop quickly. In order to decrease stopping distance, you must upgrade tire compound as well.

Well-put about the Z32 swap as well. There have been entire threads documenting the exact forces and the disadvantages of front-only Z32 conversions on both Freshalloy.com and Zilvia.net.

I can't remember where i saw the test article, but they 'upgraded' the brakes on a car and found that the car had like 8 feet FARTHER stopping distance. sure better fade resistance, more clamping power, etc, etc, but what about when you need them to come to a full stop?

i agree that keeping a stock rotor size and going with better lines, fluids, and better pads are the best performance improvement.

Re: first paragraph- Did they also "upgrade" the wheels? Wheels are a large part of the braking equation as well. Did they upgrade the tires? Clue us in more, or seem clueless.

Re: second paragraph- So JGTC cars shouldn't be running big brakes? Signal's time attack R34? Bigger brakes increase surface area. Increased surface area leads to better heat absorption and dissipation, not to mention increased pad friction area. Big brakes ARE important if the car is truly pressed.

[FD3S_pilot]

[QUOTE=GRiDRaceTech]Slotted brake discs are blank brake discs into which grooves have been cut. The grooves may extend in an arc to the outer edge of the rotor, or in straight lines.[QUOTE]

Like this right?

[JunpoweR]

Those are tight *Censored**Censored**Censored* rotors =)


I think my project car is looking at a set of 6 pot brakes front and 4 rear
($6500 KIT!!) yup but there slotted and vented..

check these out!!

[JunpoweR]

ALso I dont know if any of you knew brake fade is also caused by the pad and rotor heating up to super hot tempatures so when ur braking it creates an air pocket between the rotor and the pads friction surface..with the fluid getting hot and what not but hope someone agrees and knows what im talking about..
So when you have either slotted or cross drilled rotors it helps the air to escape also during hard use but we all have our own opinions about braking systems..
I'll just stick to Slotted ones..

[Whisky]

ALso I dont know if any of you knew brake fade is also caused by the pad and rotor heating up to super hot tempatures so when ur braking it creates an air pocket between the rotor and the pads friction surface..with the fluid getting hot and what not but hope someone agrees and knows what im talking about..
So when you have either slotted or cross drilled rotors it helps the air to escape also during hard use but we all have our own opinions about braking systems..
I'll just stick to Slotted ones..

Yes, the idea behind slotted rotors is to prevent gasses (not air, per se) from building up between the pad and the rotor surface as the pad material is consumed under very heavy braking. While this isn't much of a problem with "modern" race pads, I run slotted rotors also. What can it hurt? I've never seen a slotted rotor crack because of the slots (which is the common problem with drilled rotors). This doesn't really fall under the "fade" category as it is gone as soon as you let off the brakes, whereas "fade" is specifically a heat-related issue that is not quickly solved (quickly meaning not in a matter of seconds).

On the issue of cracking rotors, please also be aware that you can crack your rotors more easily than you might think. DO NOT PUT YOUR LUG NUTS ON WITH AN IMPACT GUN. If you let the local tire shop and their minimum wage employee put your lug nuts on with an impact gun at 250lb/ft you can expect cracked rotors sooner than later. For passenger cars you really only need about 85lb/ft on the lug nuts. Most cracks I've seen were the result of overtightening.

[illegalgarage]

Endless products are over priced.
I broke a set of front pads in half on my S13.
I preffer american made Carbon-Metalic pads.
My clutch guy who also does heavy industrial brakes (big rigs, work trucks, etc) has cut down truck brake pads to fit my S13 coupe, 300Z brakes (for the same S13 coupe, and my AE86.
I have broke the rear pads on the AE86 but that was under severe e-braking.

Max

[GRiDRaceTech]

You really should consider being less cheap with your brakes.

[hatebbobbarker]

Endless products are over priced.
I broke a set of front pads in half on my S13.
I preffer american made Carbon-Metalic pads.
My clutch guy who also does heavy industrial brakes (big rigs, work trucks, etc) has cut down truck brake pads to fit my S13 coupe, 300Z brakes (for the same S13 coupe, and my AE86.
I have broke the rear pads on the AE86 but that was under severe e-braking.

Max

endless braking in half? sounds like an ebay special or you installed them wrong, i track my car with endless pads as do several of my friends, some quite heavily and nobody plans on switching to anything else now.

[buddy]

ok
stock system with pads, fluid etc is good if everything works, but don't you also have to take into consideration the power amount of power (which entails momentum and force) and the weight of the car after mods and lightening, if any?
b/c the more momentum you have the more it takes to stop you . and just b/c you can lock the tires does that mean it is able to hold the car on the edge of lock with that much power/force behind it?
it seems like this would require more surface area (obviously) and what of master cylinder type/quality? would this have to be upgraded to keep up?
and what kind of pressure for the front and rear has max. stopping power?
the examples i'm thining of are that people are getting, now, 6-pot calipers in from and 4-pot in the rear. is this really necessary, or is it even the right front /rear braking power ratio?

[JunpoweR]

ok
stock system with pads, fluid etc is good if everything works, but don't you also have to take into consideration the power amount of power (which entails momentum and force) and the weight of the car after mods and lightening, if any?
b/c the more momentum you have the more it takes to stop you . and just b/c you can lock the tires does that mean it is able to hold the car on the edge of lock with that much power/force behind it?
it seems like this would require more surface area (obviously) and what of master cylinder type/quality? would this have to be upgraded to keep up?
and what kind of pressure for the front and rear has max. stopping power?
the examples i'm thining of are that people are getting, now, 6-pot calipers in from and 4-pot in the rear. is this really necessary, or is it even the right front /rear braking power ratio?

Well we always want the braking bias towards the front since while braking weight is transfered to the front of the car onto the tires..6\4 f\r pot brakes why..well yes for bias and also why have 6 on rear when you dont need that much braking power as the front..also you dont have to have that set up if you want you could have 6 for front and rear. just set the bias.you could do that with a valving job on the brake hoses..well mabey someone isn't as lazy as me to explain these things lol..blah blah blah..