Found this browsing ebay.
drilled/slotted rotors- good? bad? necessary?
ROTORS clicky (http://cgi.ebay.com/ebaymotors/Nissan-XTERRA-2WD-4WD-05-06-F-R-Drill-Slot-BRAKE-ROTORS_W0QQcmdZViewItemQQcategoryZ33564QQihZ012QQi temZ220103769235QQrdZ1)

Especially with the bigger meats and added weight many of us carry, these kind of rotors seem like a great idea.

So do beefier calipers for that matter, but we all know where that would leave us!

Especially with the bigger meats and added weight many of us carry, these kind of rotors seem like a great idea.

So do beefier calipers for that matter, but we all know where that would leave us!


at home wishing we could drive but cant afford gas? $3/gallon in Utah! WTF!!

Drilled/slotted rotors are a reasonable addition. They help to significantly reduce brake heat, thus increasing the coefficient of friction, along with prolonging brake-life.

there was a thread on the other xterra website indicating that holes and slots can become filled with off road stuff(mud dirt etc...) and may not be a good idea for offroad users. Street use may benefit as discussed.

I've always been a little skeptical of the drilled and slotted rotors for one reason, strength. The slots and holes have to weaken the overall integrity of the rotor. No imagine a normal da of stop and go driving in the rain hitting mud puddles. Your rotor heats up. The water drastically cools it. This happens over and over and over. Eventually it might break due from the stress of it heating up and rapidly cooling. I was once told to either do slotted or drilled, never both.

Now before anyone says so, yes race cars do run slotted/drilled rotors and those go under heavy use. Yet those things get thrown out with the half eaten burito in the garages after the race.

i recall hearing (from back in my import tuner days, lol) drilled rotors may warp, it's best to go with slotted only rotors

I've got the drilled/ slotted rotors stillen sells and have been very happy w/ them so far.

i recall hearing (from back in my import tuner days, lol) drilled rotors may warp, it's best to go with slotted only rotors
X2... but more likely to crack

drill holes provide heat ventilation for rotors

i recall hearing (from back in my import tuner days, lol) drilled rotors may warp, it's best to go with slotted only rotors
X2
X3 Thats why I've stayed away. And that they cost $$. $$ I could spend on many other things.
Seriously, I can see some validity in it. I get plenty of rocks stuck in my front brakes without them.

the main point for SLOTTED rotors has nothing to do with heat at all....the slots or to relieve and expel the gas created between the pad and rotors. the slots also help prevent the pads from glazing over which happens to the X's brakes everytime im coming down the mountain and some ricer thinks he can out drive me.....lol....they're always pissed when a truck weighting twice as much and having a center of gravity more than a few feet higher passes them up ON THE TURNS....the x handles~!!!!
anyways.....the main purpose of slots are not for cooling, the holes are~!
they create alot more surface area for the air to cool the rotor. but with drilled rotors, the holes are usually drilled out from blanks. i would not doubt if the ebay rotors were drilled out wrong.....i mean there are holed that were just drilled and there are holes that are....damn i can't think of the word...chamfered....angled.....like...the hole...looks like a V from the side rather than a ll u get what im saying......holes drilled out like ll create sharp spots which will lead to stress cracks. especially under some heat.

plus there are many ways to treat rotors to make them stronger and more resistant?to thermal breakdown..? like they resist breakage due to changes in heat. like....cryotreating, and heat treating. when done right, they raise the strength of the material greatly....

i just forgot what else i was going to type.....damn TV....
aite....so anyways.....there are alot of rotors out there that are not made right.......there are rotors that were made to be drilled and slotted...they are not the same as a rotor designed to be blank and then having a second person drill it themselves.....

the stillen rotors were designed that way.....they are quality rotors....stillen also uses AP racing brakes which are REALLY good

anyways....uh....im getting tired.... trust me...i go to school for this stuff...im mechanical engineer..... and soon to be member of the formula race team..... bastard teammates get to go to italy to race our car on farrari's proving grounds and get a tour of the plant and etc....i wish i had $2k to go....

Dude, thanks for the post. Who knew you were a mechanical engineer?

Save up and spend the 2K on mods that will last years!

that came out wrong....im studying to be a mech. engineer....most of my classes til NOW have pretty much vector this thermo that stress this....but noow.....its a class where i have to use all that and design on solidworks....freaking time consuming....last week i spent the entire week working on solidworks, never knew i could stay at school for sooo long.... i understand y people commit suicide now....its really depressing in a computer lab with 4 people at 4am....
the $2K is really just to get a chance to get to know the farrari engineers....plus i dunno....i guess its an engineer geek thing....lol im not going so im not a geek....

That's good to know. I thought rotors were all basically the same. Hopefully r1concept can clarify this issue regarding their rotors?

.....i mean there are holed that were just drilled and there are holes that are....damn i can't think of the word...chamfered....angled.....like...the hole...looks like a V from the side rather than a ll u get what im saying......

You had it right with chamfered. Have you taken dymamics yet? If not, it could make you long for the long nights of SolidWorks.

u mean...have i passed dynamics yet? im working on it....dont get me wrong....i hate solidworks...but man....beats a nights of dynamics thermo and all the other chapters of physics built into classes, ANYDAY.....graduation seems so far away
R or were u a ME too?

R or were u a ME too?

I was, but now I'm on the other side of the classroom.

when I worked a little on a trans am cars in the 90's, they were only using slotted rotors with AP brakes all around.

It's stupid to use them on an suv since the rotors will need to be changed at every brake job and , if anything, they won't work well with normal pads since there will be less surface area to have friction against.

You'd be money ahead to fit bigger custom brakes rather than drill holes in your rotors. If crossdrilling is done right, you might prevent brake fade on a road course or autocross, but the small stock brakes still won't work better with 35 inch tires, cross drilled or not.

but the small stock brakes still won't work better with 35 inch tires, cross drilled or not.
True, and as mike said the drilling reduces friction surface decreasing performance unless you upgrade to bigger brakes, of course.

And won't bigger brakes mean bigger calipers and thus--the dreaded wheel contact? Now even our stock wheels won't fit, lol!

Sorry, just looked more closely at my last post. I don't mean to suggest anyone's running 35s with OEM rims. I'm just thinking what about beefier brakes with 33s, or whatever? What are our options with so little room around the backspace?

these nissan brakes are leaps and bound better than what my jeep TJ came with..and still do. bigger tire have side effects on any vehicle.

guys....the WHOLE point of slotted/drilled rotors are not so your vehicle can stop quicker.....no matter what rotor you use, it will not reduce stopping distance. maybe bigger rotors but just because they're cross drilled doesn't mean anything

slotted drilled rotors are to reduce brake fade/glazing....the rotors are designed to cool down alot faster. ONE of the reason people experience brake fade is the heat. the more often you brake....ie...track days or comming down the mountain.....the less time your rotors have to cool down. in turn...they heat up more.....
this is where pads come in.....there are various types of pads you can buy, all with different heat ranges.
pretty much....if it brakes good at low temp, they suck when hot...vice versa....
STOCK OEM PADS are great when brakes are not super hot...once they do start to heat up, they suck~!
stock are usually organic....
METALIC pads are good and will work alot better when hot, the problem with metalic is they EAT UP THE ROTOR quicker.
when u get to expensive pads, they tend to have carbon or are carbon ceramic.....these work EXTREMELY WELL when HOT....they will work even when you rotor is glowing red hot....RACE CARS USE CARBON...ENZO uses carbon......THE BAD PART....they squeek when cold....not just a small squeek...more along the lines of man..that guy needs a brake job squeek.......

BIGGER ROTORS
bigger rotors might decrease stopping distance a little....but considering we have 4600lbs truck...they dont help much. dont get me wrong THEY DO HELP....
BUT AGAIN...Big Brake Kits are made for tracks, THEY ARE MADE TO KEEP BRAKE FADE DOWN....brakefade is very minimal, next to none. THEY WILL NOT HELP US....sure they might look good, but how often do we have to stomp the brakes to stop 90-0mph 15 times in less than a couple minutes????

plus if brakes are made right....i mean the whole system, from the master cylinder(brake ratio F to R) to the brake ducts to cool brakes...there will be minimal gain from a bbk if any, interms of stopping distance.......
ugh...im getting tired.....

ok....i dont mean to attack anyone with this post......
lets say we have a 12 inch rotor with 3 inches of actual rotor which is 130 sq in minus 30 sq in of unused rotor.... so its the outer 3 inchs of the radius....that about 100 square inches of total surface contact with the pads...lets say theres 12 slots(usually less than 10), 1/8 inch wide 4inchs long. thats ONLY 6 square inchs......so there is only 6% less surface area.....
thats not going to do much at all..... thats calculation for one side of the rotor..... this does not mean that your car will stop 6% slower......
UGH~! im loosing focus again
anyways....they do not make much difference if any....

a good reason not is that guy that said we might get a rock or pebble stuck in it....that is good

damn TV AGAIN....

uuh..... yea.... you can also think of it this way...all those holes, are less surface area to heat up....lol.....ok
THE HOLES.....they provide the rotor with ALOT i mean ALOT more surface are to cool down vs. loosing pad contact area....u may be loosing ...lets say 12 sq. inchs in contact area but you'll be GAINING 3x (36sq. in)more surface area to cool it down....thats be BIG different.
SEE.....its pretty much STRICTLY to REDUCE BRAKE FADE


ok.... and for the 33 in tires and crap.... OUR TIRES ARE THICK....70-85% the width of the tire....that means that are rims are closer to the center than someone w/ low profile 25-40% with 24" rims.....

to keep it short......WE HAVE LESS ROTATION MASS than someone with DUBS.... because we have small rims and fat tires, that means the weight is closer to the center which makes its alot easier to stop. dubs push weight further out which is much harder to stop.....
if there was a graph....amt. pwr needed to stop vs. weight pushed futher from the center...the graph would be expodential.......


BRAKES ARE Changed depending on race. if brakes had to be changed everyrace....that would not be very cost effective, considering the amount of money it cost THEM for brakes....look....if nascar had to change brakes after every race, what happends in a lamans race....they would have to do a brake job several times in the middle of the race. that doesn't make sense.......
it would make more sense if they were super anal about weight savings and they calculated how thick each pad and each rotor would need to be depending on each track.....but that would be hard.... calculate temp of day, temp of track, how much braking needed per turn, how many left turns vs. right turns....pressure.... but if they're that crazy they have take into account the quality of materials in the rotor and pads, is there any surface imperfections, no...not imperfection but....damn forgot the word again......IMPURITIES! ahhh..... stuff like that

rotor life depends more on how hard someone will brake and the type of pad being used. again...metal vs organic vs ceramic vs carbon etc.
im sure ill have more to say later......
i hope u guys are getting an understanding of how much crap the engineers think of when designing stuff.....dont get paid neough to do all this

correct buddy drilled holes are for heat ventilation while slots are for a better braking bit.


the main point for SLOTTED rotors has nothing to do with heat at all....the slots or to relieve and expel the gas created between the pad and rotors. the slots also help prevent the pads from glazing over which happens to the X's brakes everytime im coming down the mountain and some ricer thinks he can out drive me.....lol....they're always pissed when a truck weighting twice as much and having a center of gravity more than a few feet higher passes them up ON THE TURNS....the x handles~!!!!
anyways.....the main purpose of slots are not for cooling, the holes are~!
they create alot more surface area for the air to cool the rotor. but with drilled rotors, the holes are usually drilled out from blanks. i would not doubt if the ebay rotors were drilled out wrong.....i mean there are holed that were just drilled and there are holes that are....damn i can't think of the word...chamfered....angled.....like...the hole...looks like a V from the side rather than a ll u get what im saying......holes drilled out like ll create sharp spots which will lead to stress cracks. especially under some heat.

plus there are many ways to treat rotors to make them stronger and more resistant?to thermal breakdown..? like they resist breakage due to changes in heat. like....cryotreating, and heat treating. when done right, they raise the strength of the material greatly....

i just forgot what else i was going to type.....damn TV....
aite....so anyways.....there are alot of rotors out there that are not made right.......there are rotors that were made to be drilled and slotted...they are not the same as a rotor designed to be blank and then having a second person drill it themselves.....

the stillen rotors were designed that way.....they are quality rotors....stillen also uses AP racing brakes which are REALLY good

anyways....uh....im getting tired.... trust me...i go to school for this stuff...im mechanical engineer..... and soon to be member of the formula race team..... bastard teammates get to go to italy to race our car on farrari's proving grounds and get a tour of the plant and etc....i wish i had $2k to go....

Every road racer and cone dodger I ever talked to told me that cross drilled rotors were nothing but bling for car shows. Something to show off through your huge wheels. More trouble than they are worth.
A lot of them run non-drilled/non-slotted 2 piece rotors for reduced weight, and to keep heat away from the wheel-bearings. Wheel bearings don't like being cooked. Then they pick up some good pads.

Bigger brakes can help manage heat with a larger mass of metal to wick it away. They also provide more leverage on the axle.

The problem is, most modern factory brakes are more than capable of locking the tires, hence the need for ABS. If you can lock the tires, you don't need more leverage or bite, you need better tires to stop more quickly. Otherwise your awesome upgraded brakes won't help you stop any quicker, they will just make your ABS work harder.

With a truck(after a tire upgrade), you don't only add more weight and momentum for the brakes to manage, but the tire actually has more leverage on the axle due to the increased diameter.

In this case, if you can no longer lock the tires, or trigger the ABS, then a big brake setup may help you, or better pad selection, or both.

Cross drilling will not increase bite. It will also do very little to manage heat. They can also lead to issues during off-roading, as already mentioned.

I would have to research the pro's and con's of slotting again to give any real opinion on them.

I have a feeling heat management on a hill decent is the biggest issue you would see with these trucks. I think proper pad selection would clear that up for most people.

what? non drilled non slotted? y would anyone run that if they are a road racer, autocross, etc. those people do not know what they are talking about. well more than 90% of the people that you meet will no nothing about what they are talking about. even on the forums, everything is hearsay...not to bash on forums.....not one bit, but....LITERALLY everything is hear say, how many people on the forums actually go out do half the things they say they do...how many people really work on cars...i dont mean oil changes, i mean open up the heads and do valve jobs and what not, not to say that a valve job is hard, or clearancing bearings are any bit hard.
once you get the hang of it, its pretty easy....
cars are just big legos for adults.....
i mean...man....HOW WOULD U REALLY KNOW IF YOU'VE NEVER DONE IT..... thats like saying a every housewife who watches iron chef/any cable cooking show can go out and be the headchef at a 5* restaurant!
anyways.....IM SAYING THOSE PEOPLE YOU MEt....MOST DONT KNOW.....
Forums are a great way to learn,pick up on skills you never learned before, hang out with people of the same interest(the X), but you can not believe everything you read and see.....

i digrese.....anyways....the rotors.... did you not read what i posted above? sorry if i sound like an ******* but man.....i dunno what to say.....
ok.....weight savings....cross drilling and slotting always take weight off the rotor. some people go ahead and drill out holes on other parts of the rotor besides the pad contact area. ie...the hub area...all to save weight. it does not make sense that a cross drilled rotor of the same material would have more mass than a reg. blank rotor.

oh i read ur post wrong....2 peice rotors....yea they can save weight running a 2peice....but i dont see y they wouuld just run a blank 2 peice....yea theres benefits, but if they're running costly 2 peice rotors, than y not run the slotted too and reep all the benefits.
and im pretty sure u meant surface contact area rather than mass when talking about bigger brakes
most bbk are 2 different types of metal, usually aluminum for the rotors hat. and the ....braking part of the rotor being something else.... the reduced weight of 2 peice rotors and releiving the hub/bearing are some benefits, but the 2 peice rotors also aid in cost, they dont have to manufacture the whole thing, so when it gets warped, only the outter ring needs to be replaced. same concept as running 3 piece rims. plus different materials maybe purchased.
and bigger brakes dont mean they are heavier, they can leave rotors as iron, or they can switch to different types of alloys and or run the "carbon ceramic rotors" which are real race rotors. again...F1 and enzo, porche...etc. those rotors are alot lighter than cast iron.....BAH...im tired again...i hate skewl



i agree with on leverage and everything else written in your post BUT the first paragraph.

but just because you upgrade the diameter of the tires does not mean than you will loose braking power. ALOT has to do with the type of tire and type of compound its made out of.....
i have 33" Mt/r on my X right now and ill tell you, theres plenty of braking force to lock my tires up.....plenty.....

I'm hearing what everyone's saying here and it's great info.
I think the point should be made that it really comes to quality.
There are tons of ***-ass ebay drilled rotors out there that some guy with a drill press is turning out of his workshop.
If you go with Brembo, AP, EBC... a reputable company you'll be safe.

yea....thats best way to put it...i didn't have to stress out....
but beware, these people know they trust name brands and they stamp their site so it seems like you are getting the real deal....plus..alot of the companies use brembo blanks and drill it themselves....

i was not specifically talking about this forum...i think this forum is great too, but i was talking about forums in general....mostly the 240sx and honda forums.....UGH!!!!! freaking people...they get on my nerves alot...even when you meet them and explain everything out.....ugh...man...they get on my nerves! think they know everything from just talking to other idiots....like...the idiots gather together to come up with a bunch of crap to piss people who do know ssomething off! man....im sorry...i just needed to vent
people on this forum and a few other small forums are great....really nice people....just all the young people forums.....lol....although im young too

I feel that the drilling/slotting benefits are just overrated. Rotors are already vented most of the time. Take a look at the amount of cooling area available there, right through the center of the rotor. Thats my own opinion based on my research. I've been wrong before. :drunken:

I agree that there may be some small benefits, but that they are not as dramatic as some think.

Here is a good read on brakes if anyone is interested.

Nasioc Brake upgrade FAQ (http://forums.nasioc.com/forums/showthread.php?t=1154081&highlight=brake+faq)

Subaru oriented, but good universal info non the less. Discussions of big brake kits, pad selection, reducing fade, rotor selection, ect. [/url]