Heiserb

http://www.amazon.com/Power-Stop-K69...pe=5&carId=002

I found this kit on amazon for under 200$
and am very interested, wanted to get some feedback

also i feel pretty disappointed when i look at my rear drums and if i do a front disk swap, i should also get rear disks to combat a nose dive on serious breaking.

all feedback is appreciated

pwnsauce

no, but at one time i wanted to do this untill everyone started saying the holes will crack. if you really want to do it id say just do slotted rotors not drilled.

ezone

I've cut spiral grooves in rotors with the brake lathe.
It's not what most people want though.

lowlife9

Y U got race car ???

SlimRisk

They look nice yeah, but unless you wanna do some 100-0 times or you're doing some serious racing, it's not worth the money. A 2,500 lb car isn't hard to stop. Suspensions swaps FTW. That's what I would spend my money on personally

04 Honda Civic

iTrader: (2)

Buy name brand rotors. Many cheap aka china ones warp over time.

04 Honda Civic

iTrader: (2)

From what I read, if the holes are cast in the rotor it is ok. Not sure how true that is though.

sdaidoji

iTrader: (1)

erm...
heiserb, have no idea what makes you think that drilled or slotted would make yer braking better...
First off, the best way to improve braking is to put sticky tires. In the end, no matter what brakes, the tires are the ones that do the work...
2nd, the drilled ones even if casted in will crack if the holes are not rounded in the edges (it's geometric factor mainly, concentration of stress in sharp edges - just rounding them will not do either, it needs to be well designed).
using big brakes will not make you stop faster either. They will just resist better to fading.
Oh, yeh, goggling returned thousands of pages, this is one of them:
http://www.rx7club.com/showthread.php?t=480082
unfortunately wikipedia is on strike due to SOPA...

One of the worthy posts is the first:
"More facts about rotors. May the great myth of drilling rotors for improved cooling finally die...

Darrick Dong; Director of Motorsports at Performance Friction.

"In the days of asbestos pads there was a gas boundary layer that appeared at the interface area of the pad and rotor. Although that gas boundary layer still occurs it is much less of a problem with modern friction materials. Slots are more than adequate to carry that gas away. Years ago that gas boundary, along with reducing weight, led to the popularity of drilled rotors. However, in the intervening period, the myth has persisted that cooling is the main reason for drilled rotors. Anyone that tells you that drilling makes the disc run cooler is smoking crack."

Why is Dong so adamant? Because he works with racing brake systems for a living and it isn't too hard to take two identical rotors, drill one of them and slot the other, put them on a brake dyno and measure temps and life. "

Another:
"Quote:
Originally posted by spoolin93r1
it seems everyone wants to downgrade drilled rotors, yet they never provide factual proof.

I've seen a lot of pictures of crossdrilled rotors that cracked during track use. I've never seen a single picture of a plain or slotted rotor that cracked.

Crossdrilling is fine for the street, especially if the edges of the holes are rounded to prevent stress risers (and eventually cracks) from forming, but anyone who thinks that it's anything more than an appearance mod needs to do some research.


Quote:
if it wasn't worth doing, brembo and many other companies wouldn't still be doing it

Of course they would, because they can charge a premium for it. People think it looks good, and most of them don't know or don't care that there's no performance benefit. Most people don't track their cars anyway."

this one is worthwhile too:
Quote:
Originally posted by spoolin93r1
so basically everyone is sticking to their guns about the cross drilled being junk without providing proof?

Darrick Dong; Director of Motorsports at Performance Friction: "Anyone that tells you that drilling makes the disc run cooler is smoking crack."

Power Slot: "At one time the conventional wisdom in racing circles was to cross-drill brake rotors to aid cooling and eliminate the gas emitted by brake pads. However, today%u2019s elite teams in open wheel, Indy and Trans Am racing are moving away from crack prone, cross-drilled brake rotors in favor of rotors modified with a fatigue resistant slotting process."

Stop Tech: "StopTech provides rotors slotted, drilled or plain. For most performance applications slotted is the preferred choice. Slotting helps wipe away debris from between the pad and rotor as well as increasing the "bite" characteristics of the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage. Many customers prefer the look of a drilled rotor and for street and occasional light duty track use they will work fine. For more severe applications, we recommend slotted rotors." (Note that even though Stop Tech sells both drilled and slotted rotors they do not recommend drilled rotors for severe applications.)

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."

From Waren Gilliand: (Warren Gilliland is a well-known brake engineer in the racing industry and has more than 32 years experience in custom designing brake systems ...he became the main source for improving the brake systems on a variety of different race vehicles from midgets to Nascar Winston Cup cars.) "If you cross drill one of these vented rotors, you are creating a stress riser that will encourage the rotor to crack right through the hole. Many of the rotors available in the aftermarket are nothing more than inexpensive offshore manufactured stock replacement rotors, cross drilled to appeal to the performance market. They are not performance rotors and will have a corresponding high failure rate"

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...However, with today%u2019s race pad technology, %u2018outgassing%u2019 is no longer much of a concern...Slotted surfaces are what Baer recommends for track only use. Slotted only rotors are offered as an option for any of Baer%u2019s offerings."

Grassroots Motorsports: "Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the '40s and 50s, not a whole lot. Rotors were first drilled because early brake pad materials gave off gasses when heated to racing temperatures, a process known as "gassing out." ...It was an effective solution, but today's friction materials do not exhibit the some gassing out phenomenon as the early pads. Contrary to popular belief, they don't lower temperatures. (In fact, by removing weight from the rotor, they can actually cause temperatures to increase a little.) These holes create stress risers that allow the rotor to crack sooner, and make a mess of brake pads--sort of like a cheese grater rubbing against them at every stop. Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it...Slotting rotors, on the other hand, might be a consideration if your sanctioning body allows for it. Cutting thin slots across the face of the rotor can actually help to clean the face of the brake pads over time, helping to reduce the glazing often found during high-speed use which can lower the coefficient of friction. While there may still be a small concern over creating stress risers in the face of the rotor, if the slots are shallow and cut properly, the trade-off appears to be worth the risk. (Have you looked at a NASCAR rotor lately?)

AP Racing: "Grooves improve 'cleaning' of the pad surfaces and result in a more consistent brake performance. Grooved discs have a longer life than cross-drilled discs."

also from AP: "Cross drilled...can compromise disc life. Radiused drilled...mainly used for aesthetic reasons on road applications."

...I'll keep looking for more. Note that these quotes are from people who are in the racing business, not the poser business. "

Note 1: I could have explained this, but copying and pasting from the internet is easier :P

Note 2: Porsche, Ferrari uses drilled, but the brakes are inspected every scheduled maintenance for crack (hint, hint!)

Note 3: all the above refers to very high temps in the racing environment. Most road use should be fine. Anyone that ran a track day do know how scaryly the brakes start to fade... Temps are monstruously high, only road condition to ever come close would be a 20 mile canyon downhill, i guess.

MindBomber

hint, look at the picture.

the slots are going the same direction for both rotors, driver and passenger.

sdaidoji

iTrader: (1)

^ bwaaaaahahahaha! I did not even bother to click on the link so did not notice!!!!!!

sl33pyriceboi

iTrader: (3)

here is the answer to what you want to know HEISERB.

its simple.

the more holes/slots that there are on a rotor, the less SURFACE AREA.

less surface area = less brake pad contact = decrease in braking power.

look at our rotors, its a small little rotor, like 10"

now go look at an expensive car (lambo, higher class benz, M3), look how HUGE their rotor is...they can spare a few holes.

the is the basic dynamics of why you shouldnt get drilled and slotted

Heiserb

I wanted to know if anyone has done them because I've always been interested in them being that high performance cars that was already mentioned use a similar concept, and the link was just to use as reference actually the one i linked was 130$ including shipping defiantly brakes aren't a spot where I want to cheap out. But it was the simplest link i could find. Now for my second question that wasn't answer has anyone swapped out their rear drums for disks. I am not racing but disks look and perform better even under common use.
Has anyone ever swapped out their rear drums for disks?
And currently I'm running performance tires just to avoid the get better tires b4 u swap your drums comment i see coming

sdaidoji

iTrader: (1)

rear disks?
yeh just need to use the search function (yet again...)

maxtierney

iTrader: (5)

I've got drilled and slotted rotors. They were a "freebie upgrade" thrown in by Wilwood for a three-week shipment delay. When I replace my rotors, I'm going slotted only. Most track-day guys I know use blanks if/when possible. Primarily for being cheaper to replace and the better heat dissipation. As stated earlier in sdaioji’s post, I prefer slotted rotor for the street because of the clean/even wear on the pads, as well on the rotor. No grooves or waves along the surface. Only drawback is that it wears out the pads faster.

MindBomber

Drum brakes are lighter, less expensive to maintain and will not hinder performance at the street or autox levels. The only time a disc to drum swap could be considered anything but cosmetic is if significant power is added and you take up road racing. There are very serious and competitive racers who do not swap to discs for the reasons listed above.

maxtierney

iTrader: (5)

+1 on that. The only negative knocks on drums vs. disks was concerning water dispersement and some fade issues on tracks. For 99.9 percent of conversions, it's all about cosmetics.

ezone

(I posted this in the other nearly identical thread too.)

A relevant discussion was going on today on CL. I know electrickytech, he is a longtime racer. Knows his stuff. Check the whole thread.Yeah, I know it's CL so there is some BS too.

Why do they drill holes in rotors?
https://forums.craigslist.org/?ID=205275257


http://www.torquecars.com/articles/brake-fade.php
"A brake pad will start to smoke as it gets beyond its operating temperature, the layer of gas emitted will act as a lubricant between the two friction surfaces and will be manifest as ineffective brakes."

Hmmm. "...the layer of gas emitted will act as a lubricant between the two friction surfaces...."
The holes and slots let these gases out so the pads can maintain contact with the rotors.

Read on:

http://www.torquecars.com/tuning/brake-mods.php

"The heat is dissipated from the pad by the discs %u2013 a vented disc has a central channel which increases the surface to air ratio of the disc and created better and faster cooling. Drilled discs also increase the air ratio and along with grooves help to prevent a gas build up between the pad and the disc and keep the pads %u2018clean and sharp%u2019."

MindBomber

That's a good little discussion.

I think the key piece of information is, "a brake pad will start to smoke as it gets beyond its operating temperature", and furthermore, the amount of smoke produced should directly relate to how hard you are pushing the car. On the street, it should never feel any different than braking on a wet road, I've pushed my brakes extremely hard going down hill on mountain roads and they have never reduced to less than stopping power comparable to braking on a wet road. I switched to powerslot cryo front rotors, the only stock replacement slotted rotors I would ever even consider, and I feel little or no difference from stock. If I were on a road racing course, heating my brakes until they glow red hot and the brake fluid is boiling, I would probably feel a slight difference, but never on the street or autox.

Buy good, blank replacements.

ezone

I have faded brakes many times, in various cars. None were designed to do what I was doing with them. I'll agree that it is somewhat similar to wet brakes.
Brakes work on principles of friction, and friction generates heat.
The brake fade alone is just a loss of friction against the rotor surface.
Chemistry and Physics classes made me think it was heat alone causing the coefficient of friction to drop.
The articles explain well what really happens when brake pads are involved.


I have had brakes hot enough to BOIL THE FLUID and LOSE ALL PEDAL.
Now THAT gets scary! ZERO control!
Ever keep on driving after a caliper seizes? This is what happens somewhere around the time the rotor glows and smoke is rolling out of the wheelwells.

sdaidoji

iTrader: (1)

hahaha! now it's getting a real discussion! great!
i have had all four drum brakes go out in me old bettle before, pedal all the way down - scaaary! but them, civics get front disks where most of the braking is done anyways