I was wondering what are the pros and cons on drilled, slotted and combined rotors... also what are you guys running... by the way i have a 91 dx crx.. thanx

 

Cross drilled/Slotted
Pros:
-Spend more Money

Con:
-Pro to crack under heat and stress
-Not necessary
- Do not cool any better than a normal rotor
-No performance gain

I along with everyone else run a solid blank from auto parts store or Brembo. There is no need for cross drilled or slotted. I had them and they did nothing but empty my bank account a little more. They gave me no performance gain on the track what so ever.

 

thats basically it...ull spend more $ b/c ull ware out the brake faster also

 

Brembo blanks or stock solids are the way to go
Drilled or slotted , drilled and slotted
If solid rotors are good enough for F1 cars then there good enough for me

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Red_ED8 &raquo;</TD></TR><TR><TD CLASS="quote">Brembo blanks or stock solids are the way to go
Drilled or slotted , drilled and slotted
If solid rotors are good enough for F1 cars then there good enough for me </TD></TR></TABLE> exactly...if you are baller then you have the big drilled/slotted rotors. I had a pair of brembo blanks, and IMHO those were easily the best choice.

 

I cant believe what i am seeing, Its a proven fact that slotted and drilled rotors are far better then a solid, I am super shocked to see responses like this, to the starter of this thread, please go talk to road course racers they are the guys who have the day in day out proof that you need. Now incase my 10+ years of experiance means any thing to you i will say this, drilled rotors can be prone to crack, much more so if they are a stockish rotor that was just drilled, if they are cryo treated good quality rotors the chance of cracking drops to almost 0 , now slotted are a diiferent story, these almost never crack unless again are a cheap quality. please dont think i am calling these guys liars but its clear they never really road course raced and did long term testing of each type. Now as to why a slotted and or drilled rotor is better, many people think its about cooling and this isnt 100% correct, when a brake pad and rotor get super heated the gasses produced form between the rotor and pad, this is what you feel when you have brake fade. the pad is forced to float on the gasses and is no longer able to make 100% contact with the rotor, the slots and or holes give these gasses a way to escape from between the pad and rotor. Now i will say this with a light car like a crx or civic the brakes dont have to work as much as the brakes on a car weighing 3000+ ibs do, so yes very often normal rotors with upgraded calipers can be used and with good results, but that does not make them "better" , as with any thing if you buy cheap rotors just for the looks they will most likely crack.
To compare F1 brakes is not a good idea, the guys who you see running a solid rotor are using state of the art braking set ups including the use of composite and calipers that make extreme clamping forces. this is a pic of a solid F1 rotor its carbonfiber composite, let the flames begin but in the end i know what it takes to keep my car outa the grass when a long straightaway turns into a 90 I should try and get pics of my buddys brakes from the convention last year, he though upgraded calipers with solid rotors would suffice, needless to say he had to use the brakes so hard he melted every thing that wasnt solid steel, this year he ran cryo treated slotted and cross drilled and actually finished decent with no brake issues.



Modified by boosted91crx at 8:12 AM 9/20/2007

 

https://honda-tech.com/zerothread?id=894745
https://honda-tech.com/zerothread?id=343923
https://honda-tech.com/zerothread?id=752451
https://honda-tech.com/zerothread?id=1129503

^^^from Road Race/Autocross forum

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX Toad &raquo;</TD></TR><TR><TD CLASS="quote">Cross drilled/Slotted
Pros:
-Spend more Money

Con:
-Pro to crack under heat and stress
-Not necessary
- Do not cool any better than a normal rotor
-No performance gain

I along with everyone else run a solid blank from auto parts store or Brembo. There is no need for cross drilled or slotted. I had them and they did nothing but empty my bank account a little more. They gave me no performance gain on the track what so ever. </TD></TR></TABLE>

^^^see, the right answer was posted hours ago

 

IT Guy, beat me to the punch. Also modern pads don't create gas that needs to be exhausted.

BTW...I am a Road Race instructor and had drilled, slotted and now I am back to blanks on my CRX.

 

To each his own, but if you think modern pads dont create gas your wrong, heat = gas. Try running solids on a car thats heavy and has under powered brakes for the course, they will fade like crazy, then switch only the rotors and you will see change, trust me i seen it done many times, what your talking about are cars that have brake sthat are so powerfull and large anough it really no longer matters on the rotor.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted91crx &raquo;</TD></TR><TR><TD CLASS="quote">when a brake pad and rotor get super heated the gasses produced form between the rotor and pad, this is what you feel when you have brake fade.</TD></TR></TABLE>

If you're using pads from 1974 that might be true. Organic compounds exhibit outgassing when they become very hot. But very few modern pads are organic, most are metallic or ceramic. These material do not outgas, and so do not create a gas layer to ride on. Outgassing of the pads is one type of brake fade but it is not Brake Fade. There are other causes, such as boiling the fluid, thermal expansion of parts, changes in Cf of the pad, etc.

 

If you are running a good pad the off gassing shouldn't be an issue. Even good rotors like the Brembo's that come on Porsches crack....

I hang out quite a bit with NASA in the MA and SE divisions. I'd say 90% of the guys I've seen are running solid rotors. I run solid rotors on my track car (not a Honda, and most certianly over 3000 lbs) I also run good pads, Carbotech mostly.

For me a slotted rotor or drilled rotor is less friction area for the pads to work with.

 

I didnt want to get into all that with him since his question was rotor related, but yeah you are right.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted91crx &raquo;</TD></TR><TR><TD CLASS="quote">heat = gas</TD></TR></TABLE>

To each his on on that also. Where did you learn that, Nascar Technical Institute? Here's a quick quiz for you: why does the clutch on a street car slip when it's hot? And then, why do drag racers slip the clutch before the launch to get it very hot?

 

I am sure cross/slotted rotors work for motorcycles or Porsches, but I doubt they work as well on our Hondas.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EL Vap133 &raquo;</TD></TR><TR><TD CLASS="quote">I am sure cross/slotted rotors work for motorcycles or Porsches, but I doubt they work as well on our Hondas.</TD></TR></TABLE>

Well it makes them sell a lot of Porsches, and it makes motorcycles lighter, but solid would be better otherwise. "Because someone else does it" is the worst reason to do anything because you never really know all the reasons it was done.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drdisco69 &raquo;</TD></TR><TR><TD CLASS="quote">

Well it makes them sell a lot of Porsches, and it makes motorcycles lighter, but solid would be better otherwise. "Because someone else does it" is the worst reason to do anything because you never really know all the reasons it was done.</TD></TR></TABLE>

Yeah, and look at those monster brake systems those Porsches have. Even that Chayenne (or however you spell it) has a killer brake system.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drdisco69 &raquo;</TD></TR><TR><TD CLASS="quote">

To each his on on that also. Where did you learn that, Nascar Technical Institute? Here's a quick quiz for you: why does the clutch on a street car slip when it's hot? And then, why do drag racers slip the clutch before the launch to get it very hot?</TD></TR></TABLE>
Different materials are used on the clutches,( not to mention clamping force of the PP) but any way for example in my last car( non honda) i used a clutch master stage 3 that was kevlar based, it needed a little heat to grip smoothly, some materials have better dynamic friction then others when hot. but even those clutches can be made to hot and can slip, of course now we are getting way off base since comparing clutches to brakes is not a good way of making a point. The bottom line is do your research contact the companys and try stuff your self, This is just more proof that many people have differing opinions on the same issues, some of these guys swear by solid rotors, but there are just as many and maybe more who swear by drilled and or slotted, you need to find what works best for you in the end.


Modified by boosted91crx at 10:49 AM 9/20/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted91crx &raquo;</TD></TR><TR><TD CLASS="quote">Different materials are used on the clutches</TD></TR></TABLE>

That's exactly right. Organic clutch compounds are usually used in street cars. When the friction material gets hot, the coefficient of friction increased. But we know a hot clutch slips, so what's the problem? The organic material outgasses and rides on the small layer of air created. So the race clutches such as the ceramic, metallic and kevlar clutches do not outgas. Like the organic clutch, the other materials also exhibit increasing Cf as temperature increases, which is why drag racers slip the clutch some during the burnout in order to put heat into the clutch. As you said yourself, yours grips better with some heat in it. But I'd bet my own kevlar clutch that your flywheel is not cross drilled...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted91crx &raquo;</TD></TR><TR><TD CLASS="quote">now we are getting way off base since comparing clutches to brakes is not a good way of making a point.</TD></TR></TABLE>

I think it's a great way of making a point, because they both function in very similar ways, with a friction material sliding on a steel surface. Understanding that not all materials act the same under all conditions is what prevents people from making engines out of bread or something. The moral of the story is that in the stone age when pads were made of compressed poop and outgassed, vents allowed a release of that gas. But current (1985) technology allows pad compounds that do not create this gas. The "need" for drilling or (hopefully) casting holes in your rotors should be re-evaluated, because it creates huge stress concentrations that are extremely prone to cracking. I've seen so many cracked rotors on Porches that come into the dealership I work at it's not funny. And I've seen solid rotors with cracks also. So why aggravate a problem that already can rear it's ugly head.






<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boosted91crx &raquo;</TD></TR><TR><TD CLASS="quote">The bottom line is do your research contact the companys and try stuff your self</TD></TR></TABLE>

My research is a BSME in Mechanical Engineering, and I've talked to Darrick Dong who is the head of the motorsports division at Performance Friction, he laughs at the idea of putting holes in rotors. Here's what some other companies and experts who "actually race" have to say: http://flashoffroad.com/Mainte....html

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EL Vap133 &raquo;</TD></TR><TR><TD CLASS="quote">Yeah, and look at those monster brake systems those Porsches have. Even that Chayenne (or however you spell it) has a killer brake system. </TD></TR></TABLE>

That's what the marketing department wants you to do, look at them and think that since they're drilled they're better. The calipers are painted red and yellow for a reason also, and it's not because it makes the car stop better...

 

so their is really no point of getting drilled or slotted. bcuz at my work i can get them for like 100 for the slotted and drilled and for the blanks its like 15 bucks ...
by the way its only a daily driver... i was gonna buy the slotted for looks.. lol

 

Blanks FTW.

$15 is a hell of a deal, too.

 

$15 FTW

 

Do you happen to work in NC and can get some people some $15 blanks?!?

 

sorry i live in cali... thanks for everyone though...