treyZ28

fins are the for cooling, period. If we were worried about strength we would use a solid rotor and not spend millions researching better fin design. rotor doesn't require that much support over there... 1 or 2 simple "disks" would more than hold the rotor together

however a stiffer disc will be benificial in many ways. A stiffer caliper is where its at

bruecksteve

I did, they both say it's pretty much worthless. I am reading that correctly aren't I???

treyZ28

baer said it could be useful under these conditions-

BUT those conditions are almost non existant.

Wilwood took less of a corperate strategy and said they are useless

bruecksteve

That's exactly what I thought I was reading!!! Thanks Trey!!

treyZ28

.04mm thickness variation on our rotors. How do you like them apples?

bryanz882

Here's the exact information on Wilwood:

"Q: Why are some rotors drilled or slotted?
A: Rotors are drilled to reduce rotating weight, an issue near and dear to racers searching for ways to minimize unsprung weight. Drilling diminishes a rotor's durability and cooling capacity."

I quoted only a section of the text here. That doesn't support ZPaul's arg. It almost contradicts it. Then in the part I didn't post it says the slots are to scrape away pad glazing when using vintage asbestos pads, which has nothing to do with water.

Then I love this one from Baer

"What are the benefits to Crossdrilling, Slotting, and Zinc-Washing my rotors?
In years past, crossdrilling and/or Slotting the rotor for racing purposes was beneficial by providing a way to expel the gasses created when the bonding agents employed to manufacture the pads began to break down at extreme temperatures. This condition is often referred to as “green pad fade” or “outgassing”. When it does occur, the driver still has a good firm brake pedal, but simply little or no friction. Since this normally happens only at temperatures witnessed in racing, this can be very exciting!"

Yeah having your brake pads exerting little or no friction is VERY EXCITING. Especially when you kiss the track sidewall


These are commercial sites. They are trying to sell their product to stay in business. This forum is here to give you advice from real Camaro owners. Don't be sucker and fall for the sales pitch.

Mindgame

A thou and a half is perfectly within reasonable "thickness" limits for modern machining equipment. Was I suppose to be impressed?

So that's what you were referring to as "profile clearance"?

-Mindgame

TheHeadFL

Maybe its my defective thinking but...

... the ability to lock your brakes does not indicate a good brake system. I'm sure its more than easy enough to lock the brakes in most cars w/o ABS and hit ABS modulation in most cars that do. Does that mean they stop adequately? I doubt it.

As previously mentioned, the job of brakes is conversion of kinetic energy to thermal energy, however, it would seem to me at least, that a larger diameter rotor with more mass, and a larger number of pistons in the caliper, or at least more even force distribution would be more conducive to stopping the vehicle right on the edge of lockup but not actually in lockup, as in, the ability to dissipate more heat before catastrophic breakdown of thermal transfer abilities.

treyZ28

you reasoning is incorrect. The ability to lock up your brakes shows you have the ability to reach maximum braking- in other word, a stronger caliper wont help you.

Kind of like having a 60 ft race in a VIPER or TPI camaro. More power wont help either because they are traction limited.

Same idea applies. The caliper is strong enough to stop the car, limiting factor is traction between the tire and the ground. If there is more traction there, the brake can sqeeze harder without locking up. Its more than a simple energy transfer equation.

ABS is irrelivant to the equation at this point. Take ABS out of my truck and it still wont have enough braking power to stop itself at 60mph. ABS kicks in after the wheel locks up so its a non issue. I am saying "if it has or doesn't have the ability lock brakes" not that locking brakes stops you faster- it doesn't. Only on displaceable surfaces like mud, snow, sand ect.

Quote:

As previously mentioned, the job of brakes is conversion of kinetic energy to thermal energy, however, it would seem to me at least, that a larger diameter rotor with more mass, and a larger number of pistons in the caliper, or at least more even force distribution would be more conducive to stopping the vehicle right on the edge of lockup but not actually in lockup, as in, the ability to dissipate more heat before catastrophic breakdown of thermal transfer abilities.

seems to me like you used a whole bunch of big words to real end.

Yes a larger rotor is less prone to heat fade due to its larger mass- it can act as a bigger heat sink. Is this what you are saying?

Yes- even force distribution on the pad is a very good thing. Prevents a slew of quality issues as well as promoting better perforance. More pistons doesn't warrent better brakes, but it can and usually does.

I dont think i understood your last comments

TheHeadFL

Put more simply, it seems to me, a larger rotor, having *more mechanical advantage* would be able to stop a car much more effectively without lockup. In other words, I feel that a larger diameter rotor would allow you to hold the brakes on the verge of lockup without actually locking up. Less effort is required to generate the same clamping force.

Sort of like trying to break a bolt thats rusted. You try with a 8" ratchet, and you put all your force into it, and all the sudden, you have a catastrophic break... bolt breaks suddenly, you get a bloody knuckle. With an 18" breaker bar, when it finally does break, you have more ability to modulate the 'breaking' force of the rusted nut. When it breaks, you dont bruise your knuckle.

That being said, I feel that the ability to lock your brakes at any speed does not constitute the ultimate in braking performance, just as throwing a metal bar in bike spokes is not an effective way to stop a bike, though you can bet it will lock up the wheel.

treyZ28

you missing the concept- you are way out in left feild. your last statement confirmed it.

Although a larger rotor will allow you to apply "more brake" without lockup, its also a rotating mass that is "pushing" the vehicle ahead.

A heavier vehicle will allow for more braking before lockup as well, but it certainly does not make it easier to stop.

So long as tire:road friction is equal and heat fade isn't an issue, and the calipers have enough power to lock the wheels, mass of the vehicle drops out of the equation. there is an advanced tech thread about this.

However as Eric points out in that thread- that is too much of an ideal situatation/world to even concider it.

Heat fade for a truck is a HUGE issue. Tire: road friction has too many variables. There were a million thigns.


to put it in a nutshell-
the added mass of the rotor does not help a vehcile stop faster because you can apply more of a fricitonal force before lockup. I know exactly what your saying and its wrong. Because you can apply more force, but you need more force to stop the car so it all "balances out" except that you need more "caliper power" to stop the car. so the added rotational mass of the rotor is a bad thing, but a negligable thing when compared to its benifits when heat fade is examined.

A better way to show this to you is a larger heavier wheel. Will that stop you any faster

The thermal properties of a larger rotor are very desirable

And you are way too far off base with the lockup segement of this thread. your viewpoint is way off target- almost backward.

TheHeadFL

I am not talking about larger mass helping you stop the car. Larger rotors obviously add mass, but they increase your mechanical advantage (by having more diameter, you are clamping farther from the pivot), much like a lever arm. They multiply force and reduce effort the same way a hydraulic system allows you to lift a very heavy car. Obviously, this far from the pivot, the tradeoff you make is increased rotor speed, since the molecules at the outer circle are moving faster than the ones at the center, but given good thermal transfer properties, you have more control over a braking maneuver, since force is easier to control when you are working with mechanical advantage.

treyZ28

a larger mass towards the outside is NOT an advantage- not if your trying to stop anyway... maybe if you are trying to plow through a wall

the termal properties have nothing o do with a mechanical advanage.

Tangential velocity is the same through the radius- I think... i forgot. I start school again in 2 weeks so i'll review all that stuff but...

a larger rotor will cool faster and be less prone to heat fade. The outer edge of a rotor is the hottest (except the lip area since its exposed to the air)-

I really dont know WTF you are saying.

It has no mechanical advantage, and I dont understand WHAT the hell you are trying to controll. a larger radius will have more resistance to change in velocity- meaning its harder to accelerate and decelerate.

None of the above thigns you mentioned are really related- or valid.

maybe i'm just misunderstanding you

Compstall

That "brake duct experiment" that was mentioned at the top of this thread has already been and is regularly used on F-bodies that are road raced....

- Brent

treyZ28

awesome, so its not a waste of time...

I think its going on my truck before the Camaro-
my truck has terrible fade under load or at higher speeds on downhills and such...

then agian, you try stoppping 6500lbs going 40mph