Cross Drilled rotor problems

[240speed]

I talked to my mechanics' break guy today, in which he told me that cross drilled rotors could crack under high temperatures. I've heard this info before, but only with older rotors that had bigger holes drilled in them. He made it sound like this happens all the time. He said that he has seen a couple that had been crack and advised against me continuing to use cross drilled rotors.

[sr240mike]

I've been on mine for over a year with no cracking. They probably will crack eventually. It is important that the holes are chamferred to prevent cracking.

[240KAT]

as long as theyre quality drilled and not some guy with a table drill in his basement, you'll be okay.

[Pank]

hah, please dont start this argument again.

there was a thread on an altima forum that debated this at length

[240speed]

I've been on mine for over a year with no cracking. They probably will crack eventually. It is important that the holes are chamferred to prevent cracking.

Will crack eventually? explain... So the life expectancy of a solid rotor is greater than a drilled rotor?

[Var]

if you care about longevity dont do performance mods period. Expect everything to break every day you drive your car.

[aznpoopy]

screw the x-drilled rotors...

just run blanks with high temperature aggressive track pads for the track.

westborough - true... but he's asking about a 'performance' part possibly undergoing catastrophic failure during repeated high speed braking, i.e. on a track. having a rotor crack while you are in a 120mph to 40mph braking zone would be very, very bad.

[Var]

rotors dont crack and shatter into pieces. They develop spider web cracks between the holes.

[chuy]

"Click the banner bitch" thats great

[withy]

w00t for my first post!!!111!!!!11!

if your not continuesly on a track x-drilled will be fine, they do tend to warp and crack under constant HARSH abuse. x-drilled is more or less jsut bling fo yo ride

[zero.counter]

Slotted have worked fine for me, both in hard and normal driving conditions in the past. But then, so have blanks. But I won't knock the drilled type and still have yet to see any actual MASS amount of evidence that the drilled are bad...

[240speed]

Yeah i think that he (the mechanic) was just trying to look out for the best. They were more than likely a cheep brand of some kind in which they started to crack because of over use. Or (just thought of this) what if after a long day of driving the rotors had cold water sprayed on them, lets say for a car wash... that might make them crack. The instant change in temp tends to make things warp.

[withy]

i never said that they were bad and i don't recall anyone in this thread directly saying "x-drilled is bad" (i only skimmed the thread however). However, most cross drilled rotors i have looked at cost almost twice as much as blanks...i jsut can't jsutify spending more for some that has the same performance value and could potentially break quicker.

[!Zar!]

Well, the holes are supposed to be for ventilation and to release the gasses that occur when under hevy breaking. As for the cracking I know people who have them and haven't had cracking... yet? I figure it's a trade off better performance for less life kind of like a sticky tire

[Rezlo]

rotors dont crack and shatter into pieces. They develop spider web cracks between the holes.
False sir, they actualy can fall apart seen it many times where whole cunks come off, ive got picks somewhere of my Stratus track car with the front rottors aglow slowing down and 3 days later a dollar bill size bit broke off taking out my brand new 6 pot caliper.

90% of X-drilled rottors will form minute hair cracks around the holes, thats perfectly normal, go look at any fancy porsche and youll see if it has been driven like it should be there will be some, its all in how you break them in, do it gentle as all break pad instructions tell you how to basicaly heat treat the rottors from new to withstand higher temps, its called thermal cycling the rottor.

Slotted tend to be more street friendly, but drilled still have better shear breaking anti-fade abilities, just break them in nicely and they last a whole bunch longer

[Var]

well yes.. i mean your rotors were probably already cracked. Plus my advice is circumstantial.

[240speed]

well i just ordered some kvr drilled rotors and brake pads from pdm to replace my stock. my rotors are warped anyway, so i broke down, and im going with it. one thing though, i dont have a torque wrench so should i just tighten until they are very tight? 52-74 ft. lb.

[withy]

you can jsut put them on......i've watched "mechanics" put heads back on with impacts....they are like $55 at sears and you'll use it more then once i promise, its an important tool to have.

[Var]

i got my torque wrench at Harbor Freight for 15 bucks with tax. It's a Pittsburg brand name. I know they arent great but it still works fine

[HyperTek]

If I put a body kit on my car, my detailer said it will crack, is that true?

If your not willing to take chances. then dont do it.

[Rezlo]

KVR are the brand that fell apart on me because i didnt break them in correctly, when they sent the replacements to me I thermo cycled them for about a week while driving and ive had them on now for 50 000miles with minimal cracking, just a few round the holes which is perfectly normal.

[aznpoopy]

hah, please dont start this argument again.

there was a thread on an altima forum that debated this at length

for reference:

http://www.nissanclub.com/forums/showthread.php?t=32327&page=2&pp=15

some good info in there. cross drilled rotors may not crack and crash cars 24/7, but they are a big waste of money IMO.

slotted / drilled rotors do look pretty nice though. :rawk:

[240speed]

If I put a body kit on my car, my detailer said it will crack, is that true?

If your not willing to take chances. then dont do it.

I'm just trying to figure out what's best for my car and me behind the wheel.

[HyperTek]

tehn you will be ok.. ive never heard of anyone personally that has broke a rotor.

[Pank]

unless you are running brake pads manufactured before 1923, your street cars pads arent going to outgas enough to warrant cross drilled rotors. if you're worried about the rotors warping due to heat, get better wheels, or fabricate some brake ducts.

As far as slotting, its there to "clean" the pad after it glazes over under mega-hard braking.

In conclusion:
If you're running a 100% track car that gets CRAZY MAD 200% WACKY MEGA hard driven on the track, then slotted/crossdrilled rotors may be needed, but be prepared to maintain and replace them, and always have a watchful eye (the same way you would with SS brake lines, etc).

if you drive a street car, even if its modified, save yourself the money and time and just get normal blanks, spend the money on calipers and pads

[TheSpeedFactor]

we have sold HUNDREDS of slotted and or drilled rotors and we have never once had on crack. not once in 2 years. All of ours are machined at an actual machining facility and that is where the difference lies. Their are a lot of people that buy cheap china rotors then drill them with a black and decker special. Needless to say they don't lsat too long.

All just goes back to the saying "you get what you pay for"

[SDS14Driver]

I had this same conversation with a skilled mechanic/tuner in my area a week ago. What it boils down to is you get what you pay for. If you buy those $99 rotors off of ebay for like all 4, you should probably keep an eye on them as it was probley just some dude drilling holes.

If you're paying for Brembo's stuff or some of the other major manufactorers than you'll be in good shape for a very long time, espically if you're just 100% street. Pay a little extra for a highly reputable company's work; they're well aware of the disturbed integrity by even dimpling a rotor and have the machinary to safely compinsate for it while still giving you the performance you're after.

[aznpoopy]

i still say cross drilling = little to no performance benefit.

modern pads do not 'gas'.
you are taking material away from the rotor to absorb heat.
you are taking away effective surface area to dissippate heat.

my 2 cents. theres 100x more information on google, so if you're serious go look it up.

but, i'll admit they look cool. if i wanted to give my brakes a cosmetic upgrade for regular street driving, i'd definitely slap them on there.

[OptionZero]

Blanks are more effective and cheaper, for the reasons above. Once you get over the myth you need to be cool and let everyone know you have "upgraded" rotors, you can save money and improve your braking system.

Use the money you save on pads (that no one can see, too bad), you'll feel a much bigger difference.

Oh, and buy some tires, which actually stop your car (not the brakes).

[calebxmartyr]

i've been running z32 brakes for almost a year now with KVR cross-drilled rotors with over 15 autocrosses and many many many many mountian runs with no cracks so far...

[SochBAT]

save up, buy a JDM 180sx brake "upgrade"

Bigger pot, bigger rotor, bigger pads.
I Think you can also source them from an Altima.
And you can use your stock brakelines. The stopping power is great.
Not sure how they compare to the Z32s stopping power.

[240speed]

I'll be getting my buddy's z32 calipers soon from his practicaly brand new 90 tt. so ill just have these at the most for 2 years. cant wait for those... I'll be getting them very cheep too, maybe even free.

[s13addict]

umm this interesting because i have BREMBO slotted cross drilled rotors for almost a year and so far so good..i havent heard any negitive comments about brembo but i did hear about rotora's worping and cracking...ill be on the look out...good post btw :2f2f:

[OptionZero]

Brembo makes cross drilled rotors for the same reason as most manufacturers; people who want to buy them for the looks.

If you never track your car or push it to the limits, you probably won't even notice a difference, you'll collect the looks you want, and everything will be fine.

If you seriously wanted to drive your car (not just on the street), then you'd get Brembo BLANKS.

There are no doubt tons of people who say "oh, i have cross drilled and they're fine" or "i upgraded to cross drilled and they're better than stock"

A) Of course they're fine. You never stress it to the limit at the track, so you could run pretty much anything and it'd survive.

B) If you're upgrading/replacing worn OEM hardware, OF COURSE the new stuff will be better. Had you compared NEW cross drilled versus NEW blanks, I would be you'd find the blanks are far superior, unless you were running some exotic hardware (i.e. driving a Porsche).

The fact is:
If you want stopping power, you buy blanks, you get better brake pads, and you get better tires. You flush your brake fluid and replace it regularly, you get stainless steel lines.

If you want people to notice your cool new brakes and never beat the car, you can go ahead and get cross drilled/slotted rotors.

EDIT: It's not necessarily the company, either, its' the principle behind cross-drilling. Even if it's "brembo", you can still experience failure because some shops buy brembo blanks and drill them themselves; other companys have cross drilled but specifically note that they are an aesthetic modification (see Altima thread, i.e. Wilwood).

[withy]

its funny how the same posts keep getting made and nothing has been solved. oh well, i'll keep it alive. to the people who have cross drilled rotors that havn't cracked...good for you, it doesn't make you stop any faster. you jsut paid for some bling bling.

option, i agree with you to about 95%......reason:
while traction may own all and tires should be a first upgrade for everyone i would dare say that pads, ss lines, and a nice set of front calipers would be where to put that extra $200 you saved buy not buying cross drilled rotors

+1 post w00t!!!!1111!!!11!!!