Brake Discs: Drilled, Slotted, Both, or Neither?

[XanThoZ]

Can someone explain to me the significance of the direction of the slots in slotted rotors.

I read somewhere (I can't remeber if it was SuperStreet or perhaps Motortrend?) that the direction of the slots have a significant role.

Also, on the episode of Tuner Transformation with the Sentra SE-R, the brake guy explained that slotted rotors are meant to provide more of a "bite" and not to shed gasses? Is he right or did i word this incorectly?

All responses welcomed

[XanThoZ]

people fail to realize that bigger rotors mean more rotating mass, which equates to more power to move the wheels and more power to stop them.

I can't remember where i saw the test article, but they 'upgraded' the brakes on a car and found that the car had like 8 feet FARTHER stopping distance. sure better fade resistance, more clamping power, etc, etc, but what about when you need them to come to a full stop?

i agree that keeping a stock rotor size and going with better lines, fluids, and better pads are the best performance improvement.

They had this on Sports Car Revolution on the Acura RSX Mugen Project
They increased the diameter of the rotors and despite all the engine and exhaust upgrades, they (lol) lost some power. They thought it was the exhaust, i believe, and when they put back the original, there was a even more significant loss of power. So yes, i believe what you are saying is true

[JunpoweR]

They had this on Sports Car Revolution on the Acura RSX Mugen Project
They increased the diameter of the rotors and despite all the engine and exhaust upgrades, they (lol) lost some power. They thought it was the exhaust, i believe, and when they put back the original, there was a even more significant loss of power. So yes, i believe what you are saying is true

I believe you all also..But the nsx is sorta a sorry representation of a true sports car..LOL j/k haha..and if they thought the exhaust made the car loose power I would never let then touch my car..noobies..Also my friend who competes in D1 just got his car back and it looks like *Censored**Censored**Censored**Censored*..the motor just got rebuilt but all the spot welds that the sponsor did on his ride are starting to rust and little things like taping up the hole where the rear windsheild wiper is left alone..so water got into the rear section and started to rust the chassis spot welds..what a nobie overlooking something so small ..also after spot welding the body you better wirebrush sand and repaint the areas where you welded..

so stick to stock with better pads on the street..I don't know why it's so hard to make a choice when it comes to braking..

It will take longer and yes the rotating mass is larger..

but think about these variables:
Tire contact patch. unsprung weight.brake tempatures.

The stock ones might stop better during cold or normal tempatures but after 3 or 4 hard stopd it will not brake as well as the aftermarket rotors and calipers..they will overheat and start to fade while the aftermarket system will operate better and give more stopping power when it's hot.

so I guess you noobies forgot.. stock brakes will be better under most street conditions..
but if youre going to go TOE-GHEY( lol ) or as i call it,"StreetRacing" go with upgraded pads and mabey stock size rotors slotted at most..
for the track get something bigger and you could offset the extra unsprung weight with a lighter wheel but it does cost alot of money to do that...

[GRiDRaceTech]

Xanthoz- Slots should point out and down, not out and up.

"more of a "bite" and not to shed gasses?"- Organic pads had/have a tendency to release gasses, which reduce the effectiveness of the pads as they're now separated from the rotor by a thin layer of gas and the slots provide an escaping point for these gasses.

Slotted rotors have a tendency to shave off a small bit of the pad material with each application, thus exposing the fresh, non-glazed surface and increasing bite. The actual effectiveness of this, I do not know... other than the fact that it increases pad consumption.

[JunpoweR]

Organic pads had/have a tendency to release gasses, which reduce the effectiveness of the pads as they're now separated from the rotor by a thin layer of gas and the slots provide an escaping point for these gasses.

Slotted rotors have a tendency to shave off a small bit of the pad material with each application, thus exposing the fresh, non-glazed surface and increasing bite. The actual effectiveness of this, I do not know... other than the fact that it increases pad consumption.

I also agree and to add to that,for racing larger and stronger pistons, while heavier will ensure good braking and system cooling during "race conditions"
not too important for "drift",unless you do more than 3 minute runs on the mountians,also meaning you know how to push the limit and know how it feels.slotting or drilling or even both, will help braking under extreme use but crappy under normal conditions.you just have to come up with a good combination for drift and one for race.usually just changing the type of pads your'e using.street pads such as hawks or some CarbonRace for the track.
Each pad has it optimal tempature range..streets good cold stopping surface and bad while it gets hotter.Racing Pads don't work well untill you heat them up and when there cold they lose up to 25-60% of their efficiency.so depending on your application you will have to figure something out.

on my FC
for the street would use
stock calipers(4 Piston)
Delphi Lockheed DOT 5.1
EBC Red pads
Slotted Rotors(5 cuts)
Braided Stainless lines
And make some type of cooling Duct to feed fresh/cold air to the calipers to keep tempatures down

good enough for a 4 hr mountian run i say

[illegalgarage]

endless braking in half? sounds like an ebay special or you installed them wrong, i track my car with endless pads as do several of my friends, some quite heavily and nobody plans on switching to anything else now.

Ahhhh no i had them on my S13 when i lived in japan
This was a few years back, you know before anyone had heard of eBay

Max

[maverick27]

rottors

i went with slotted rotors. y? easy slotted adds for the rotor to breath but more strenght to the rotor than cross drilled. and for people who do heavy runs be it touge or canyons brake fade is a scary thing. thats y i upgraded brakes 3z power! hahaha work great. thats just my 2 cents

[Delphince]

Xanthoz- Slots should point out and down, not out and up.

That was a bit of an ambiguous/confusing statement there bro. "Down" reverses compared to the other side of a disk, and again reverses depending on the side of the car. Unless, of course, by "down" you meant "downspin", heh.

In any case, what you want to go for, Xan, is angle it so the portion of the slot towards the inside of the disk strikes the pad first, progressing towards the outside of the disk. That goes along with centripetal force to "throw" the gas from the disk.

[blargonator]

haha i want to get some hawk pads on my stupid little honda civic, our local car forum goes on generally long cruises on fridays sometimes and obviously it being a honda civic, i can't gain any ground on the straights so i have to rely on hard braking <8- P well....anyways....this is not really going to give much to the discussion but....its a funny story about how drum brakes suck.
ok, we go for a drive to the beach, its like 45 minutes there and i notice my brakes feel kind of funny when im flying towards the new STi in front of me and its taking a while to slow down well, i stopped in time and made it to the beach with the guys. well, on our drive through the town to leave, we are coming up to a stoplight, my foot slightly resting on the brake pedal....then i feel it become easier to press, i push the pedal further, it collapses to the floor like a empty inflatable woman. i keep downshifting the rest of the trip home but luckily there were only 2 stops (downshifting was my friend) to get home. i am like 10 minutes away from home, but i am back in a populated area with lots of traffic lights. a cop pulls up next to me! im saved! i roll down my window and yell "hey! my brakes crapped out! they barely work! what should i do!???!" the cop looks over to me and says "that's too bad" as he drives away when his light turns green
i make it home safely after some scary downhill roads. we look and see the stream of brake fluid running down the passenger side rear drum the culprit was a failed wheel cylinder. we open the drum the next day and notice there is no material left on the shoe either......drum brakes rock

[itsoem]

I should be okay with just with slotted rotors and upgraded lines and pads.

[Nixon]

well, im a pizza delivery boy, i drive about 4-5 hours almost every day in traffic for a little over a year now. when i got my '89 Nissan 240SX it had stock replacement rotors and pads, and regular tires, after a couple of deliveries i would start to experience brake fade to the point where i would have to drive slower than usual and start braking a lot earlier, really bad overall brakes. then i bought brembo cross drilled brakes for the front, size is same as stock, but with good pads, tires were the same. anyways, the problem was solved, ive only experienced brake fade once after the brembo install, and that was because i was racing a fellow delivery boy across town (took about 30mins, back and forth with very hard braking), oh and as for wear, after about 5 months of installing the brembos my pads were worn about halfway while the rear stock brakes were completely gone after 7 months, so basically i drive hard on the streets A LOT, and cross drilled brakes worked for me when it comes to brake fade, never tried slotted so i cant really say that cross drilled are better but just thought id share my story, maybe the hating on cross drilled rotors might go down a bit

[zerodrifter]

everyone know why cross drill rotors are used....they look soo fing cool when the ladies can see them thought the spokes! everyone is just repeating everything in this thread my 2 cents...ha ha