Slotted or Drilled Rotors, the truth

[online170]

Less usable surface area for generating friction

LOL.

His general concensus might be right, but im gonna guess he doesnt know the first thing about physics.

Force of Friction = U-friction X Normal Force. Where (U is "mew"). Dont see any surface area in that formula.


$0.02

 

[Peter]

whether he is an expert scientist or author, im not sure is the point, i think its a great read and he presents a lot of evidence to back up what he is saying.

 

[81cutlass]

I had lt1 style brakes on the front of my firebird and the thing didnt stop worth a crap. I got some LS1 spindles and calipers so I just randomly ordered some rotors and they were drilled and slotted. Car stopped twice as good. Most of the improvement is probably from upgrading the rotor size and putting new parts on but anyways. Havnt cracked yet.

Do they help, probably not. Is it for looks, maybe. Honestly, if Porshe, Corvettes, and whatever use them there must be some engineering there.

One thing I think is people tend to get really big into brake size. Unless you have ABS and slicks your going to end up locking the tires up on the street long before your ever going to get heat soak.

My cutlass with 32 year old factory rear drums and shoes and factory front rotors with some replacement front pads locks the tires up at 50 in a panic stop. No reason to get better brakes unless I run 255 tires on all corners on non dusty roads. Yeah, they will heat soak, but im not road racing it either.

 

[Peter]

Do they help, probably not. Is it for looks, maybe. Honestly, if Porshe, Corvettes, and whatever use them there must be some engineering there.

People think they want them, because they think they are better so why wouldnt the manufacturers include them as an option and jack the price up.

ceramic brakes which are what are offered on a lot of these cars are a different story because they are clearly more advanced than their poor mans counterpart. but lets be honest 9/10 times you see these they are steel rotors that are drilled or slotted or both

 

[79loserbluebu]

The reason Corvette's and Porsche's have those rotors is because they are designed to be race cars. I hate to say it on here, but a G-body will NEVER pull as many G's on the skid pad as a Z06 or ZR1 can. If can have all the suspension and brake work in the world but the Corvette was designed for a much different purpose than a G-body...

Also if you notice on cars with the slotted rotors, they also have brake cooling ducts from the factory

That being said, the LMP and GT cars use those because they are under constant stress. Those slots are there to cool it down because they have such little time for the air to cool it down. That's not an issue whatsoever on street cars like ours unless your car is a track only vehicle.

Great example, take a look at the ZL1 Camaro. 580hp, car was designed for racing, weighs at least 4100lbs, and uses although a two piece rotor, standard blank rotors.

 

[my86442]

I like the whole thing and especially like the comment that was posted:

" known about this for a while, Dont let the ricers know"

 

[othtim]

The reason Corvette's and Porsche's have those rotors is because they are designed to be race cars. I hate to say it on here, but a G-body will NEVER pull as many G's on the skid pad as a Z06 or ZR1 can. If can have all the suspension and brake work in the world but the Corvette was designed for a much different purpose than a G-body...

Also if you notice on cars with the slotted rotors, they also have brake cooling ducts from the factory

That being said, the LMP and GT cars use those because they are under constant stress. Those slots are there to cool it down because they have such little time for the air to cool it down. That's not an issue whatsoever on street cars like ours unless your car is a track only vehicle.

Great example, take a look at the ZL1 Camaro. 580hp, car was designed for racing, weighs at least 4100lbs, and uses although a two piece rotor, standard blank rotors.

The slots are not for cooling, afaik. The slots are to remove glazing and debris. If you've ever seen LMP or nascar-style brakes there are no slots that like on "drilled and slotted" rotors. There are little U-shaped or S-shaped markings that do not go the full lenth of the rotor, my assumption is to remove glazing? F1 brakes as far as i've seen have no markings at all.

Corvettes and porsches that are actual race cars are not going to have those "drilled and slotted" rotors. Heavily drilled rotors are a liability on a race car. It's for looks, not performance, thats all there is to it. I would think that high-end sports car manufacturers would know that most people that buy a ferrari/corvette are not going to be stressing it like a "real" racecar. THe slotted/drilled are probably fine for 99% of the driving that those cars will encounter - street driving. And they look cool 🙂

The exception as far as I know is like Sprint-car brakes, because they are heavily drilled for weight savings, because that's more important than stopping power for them.

 

[jlcustomz]

I agree, drilled & chamfered also reduces unsprung weight -slightly. Race cars take whatever they can get.

I drilled & chamfered a few sets of motorcycle rotors myself years ago, not really that hard to do on a drill press after drawing out a pattern & centerpunching. I figure on the street, someone like me isn't likely to overheat them enough to crack.

And you can say, yea Idid them myself.

 

[mrlee]

Just my .02 here.

Fom the research I've done, the slots will keep the brake pads surface from glazing aka the slots basically act as a shaver thus for regular street use, not really feasable. Racing is best suited for.

Now drilled rotors on the other hand is different. They do keep the rotors cooler.

Real life, Proof in point. Once had a min-van. I was goin through rotors due to warping every 15k. Turned out the mfg to be unamed, didn't equip the vehicle with strong enough brakes and basically warped from too much heat/cool down. This was documented btw.

So i got fed up did the research and placed drilled rotors on it. They lasted on the same pads and rotors for over 60k when I sold it. Rotors were still in perfect shape and the thing stopped with more positive feedback than stock.


Sent from my SCH-R530U using Tapatalk 2

 

[Peter]

Just my .02 here

Now drilled rotors on the other hand is different. They do keep the rotors cooler.

Real life, Proof in point. Once had a min-van. I was goin through rotors due to warping every 15k. Turned out the mfg to be unamed, didn't equip the vehicle with strong enough brakes and basically warped from too much heat/cool down. This was documented btw.

So i got fed up did the research and placed drilled rotors on it. They lasted on the same pads and rotors for over 60k when I sold it. Rotors were still in perfect shape and the thing stopped with more positive feedback than stock.


Sent from my SCH-R530U using Tapatalk 2

all that means is you had a shitty set of regular rotors, doesnt mean drilled rotors were the solution. they were just an upgrade over a terrible set of rotors