b15 brakes same as....?

[NX 2000]

>From: "Kevin J. Hart" <khart@usit.net>

>going to pick up very very marginal surface area.  Ok then you multiply
>that
>by the number of holes.  Ok you pick up a little extra surface area.  Which
>on a daily driver means jack squat

I think your numbers could be a little better.  But with your numbers, a 1/4
inch hole through 1/2 inch disc.  Each 1/4 inch hole you will lose 0.10
inches squared of surface area.
A 1/4 inch circle has a circumfrance of 1.099 inches and with the 1/2 inch
width, total area of the drilled area is 0.5495 inches square.  So, in the
one circle drilled you gained approximately 0.4495 inches squared of surface
area, and multiply that by the number of holes drilled into the rotors.
Now, on a daily driver, the extra surface area more than likely means very
little.

> > taking a bit more material off the flat part of the rotor and increasing
> > surface area.  You cannot deny that.

>the benifits from sloting have absolutely nothing to do with cooling power.

Now where is the rest of my post?  I said slotting will add more to surface
area, you did not deny that.  Like a heat sink, with increased surface area,
it can disipate more heat, in theory.  I never said that was a benefit of
slotted rotors.  But you also cannot deny that it is possible, if the brakes
are driven that hard.

>what the slot does is help clean off the surface of the pad of any glazeing
>it may have created.  And help disapate gasses(which most pads made these
>days do not put alot out) and water when they get wet.

But you did not state any of this in your original reply about brakes.
Again, if the person went onto SE-R.net and did his reading, he would have
known that, but not from your original reply.

> > Since you kindly added that in, my original reply was to Kevin who said
> > cross dilled rotors have no effect on braking unless you are talking
>about
> > above 90 mph speeds.  My reply was you are contradicting yourself by
>saying
> > no effect and yes effect above 90 mph.  And the link to SE-R.net allows
> > people to read the somewhat truths behind cross drilled and slotted
>rotors,
> > unless you are saying Mike is blowing bananas...

>No Mike isnt blowing bananas.  And if he was, he would admit it.

But that was an obvious one.

But
>re-read what he said..."Overall, I feel that drilled sport rotors are
>mostly
>a cosmetic trick" show me any rotor on the market that isnt in this
>catagory
>then ill show you the price tag of probaly hundreds per rotor.  I do not
>contradict myself by saying what I said, misunderstood and poorly worded
>yes.

Not to be too anal but poorly worded and contradicting yourself in this case
is the same because you said drilled rotors don't help brake, then the next
line you said it will help if you are going 90+ mph.

  What Im saying is on a street car, or even a lapping car, there is no
>benifit to be picked up by crossdrilled rotors

Now Kev, would this be from personal experience or heresay?  I have no
personal experience with cross drilled rotors or slotted rotors on a track
or even the street.  All I offer is what I've read and theory.  Whether or
not it is truth is a whole other story.  All I am doing is offering more
reading to those that ask these questions and have them make their own
choices.

> > judgement.  BTW, Porsche use cross drilled rotors stock

>The random cross drilled rotor(powerslot comes to mind for a distrubuter)
>are not better and not "proper" rotors.  They are for show and end up
>cracking anyway.

Now, if you said this originally or it showed up on Mike K.'s write up then
whoever was asking about brakes would have more info when making their
choices.

  Oh god here comes the Porsche arguement.  Id like to see
>the life expetancy of one of their rotors.  One reason they are on there is
>people can afford such things.

Now that is utter BS.  I only mentioned the Porsche rotor because Pat so
nicely mentioned that SCCA level (amature) and autocross do not allow cross
drilled rotors and that those racers bitch about seats and ecu and airdamns
but not cross drilled rotors.  He said perhaps those racers know of or heard
about the real benefits of cross drilled rotors.  I only offered a counter
argument to that statement.  I in no circumstance said Porsche uses cross
drilled rotors because they are better than flat rotors.
And the "they can afford it because they own a Porsche" is utter BS and you
know it.  I'd expect that from a ricer and not from a veteran of this list.

They are not the standard rotor, one thing
>the holes are cast into the rotor not drilled IIRC.  Doesnt mean they arent
>prone to cracking.  Also Id like to see some data why they are on there.

Whether they are drilled or casted in, there are lots and lots of little
holes in their rotors.

>Test a set of non holed to holed and see what happens.  On a street
>car(which is what the majority of Porsche's end up as) it wont make a
>difference.  Then on track it may make a hair...but if you are fadeing the
>brakes, more than likely you will do it no matter what extra parts you
>throw
>at it.

Okie.  Yeah...   We have a winner here.  You are generalizing here.  Let me
ask you this, how do YOU know that if you drive your car hard enough for the
brakes to fade that "more than likely you will do it no matter what extra
parts you throw at it"?

>Well most of the people see them on race cars and automaticly think they
>will help them on their car even buying cheap ones.  It doesnt.  Hell i
>remember GRM doing a study on it and even pulled out the math on it.  But
>its almost impossible to find unbiased facts on anything these days.

Funny you would mention that.  =)

  I like
>my smooth rotors they are friendlier on pads and can easily be surfaced,
>and
>not going to crack as quickly or easily as cross drilled.  Slotted atleast
>has some benifit not just conjector of it they work

Is this factual, or unbiased heresay?

we would do some back to back
>testing on the air field that Matt has access to.  See if they stop any
>better or if we can get them to resist fade any better.  Totaly scientific
>as possible and unbiased.  hell someoen show me the data and ill shut up.

I think this is a very good idea.  Only things to change is rotors.  Keep
the tires, pads, and speed constant.
Well, maybe try a range of different speeds.

My original post was meant to point out that there is reading material about
brake rotors for the person who originally asked.  Like I said, read Mike
K.'s writeup and then make your own descision about cross drilled, slotted
or oem type rotors.  That's it from me on this topic.  Enjoy the ride.  =)