Grims

I bought the drilled and slotted with out doing my research first. I have noticed no braking performance increase, and am just waiting for them to crack

CALL911

From what I understand, the full race applications such as on the C5R ect. Have solid rotors because the air ducting cools them enough, and the rotors are much stronger.

Even by having more mass (larger rotor) to stop you with, these still will get hot and warp won't they? Even though they are larger, the caliper is larger with bigger brake pads as well. This would make the stopping easier, however they still can be put to their limits from a high speed braking, and as a result warp won't they? Again, it seemed as though the plain rotors would warp in no time at all after some hard stopping for a couple months, whereas the X-drilled and slotted ones have held up for years. Why? Is it that the material is stronger in the rotors? If so, is there any plain rotor that is stronger than say a stock one?

StephenDeli22

In extreme applications it seems rotors are not x-drilled. Formula One, ALMS and all those other high perfomance vehicles dont use them. I know they use carbon fiber rotors too. Im not expert but you would think with big piston calipers the holes might comprimise the structural integrity of the rotor, maybe leading to failure in extreme high performance cases.

For our cases maybe the x-drilled rotors offer a little bit of venting that bare rotors do not have. Kinda moving off of CALL911's post, the x-drilled rotors for street applications might give the venting that our rotors need to stay straight, we do not have cooling ducts. Bare rotors just simply have nothing to cool themselves off with.

TobyZ28

Wouldn't this be easy to test? Just run a skidpad with normal rotors, put in some some slotted ones, bed them in properly and repeat the skidpad test again, From a higher speed.... Repeat for cross drilled next.. You could even throw in a disk thermal reading if you have the right tool immediatly after each stop...

Has anyone or does anyone know anyone whos done any testing like this?

Greed4Speed

YES!!!!
Stock front rotors are very light, weighing in at 16 lbs
Many aftermarket stock replacement blanks are 18.5-19 lbs.
Stock sized Baer rotors are over 20lbs.

Just because a rotor has more mass DOES NOT mean it is larger.

Saying your rotors lasted "years" is misleading since they have only lasted a mere 15k miles in those "years." I have over twice that (~35k miles) on my Wagner stock replacement blanks and no warpage. There are many people who put a season of autoX on aftermarket replacement blanks with no warpage.

The venting theory is incorrect. There is no outgassing with modern pad mterials. So what are you venting??? They won't increase ventillation either. Something spinning that fast with a hole that small on a flat surface isn't going to get any air into the hole. You would need forced air across the surface to get it into those little holes.

Quit speculating and do some searches in here, ls1tech or ls2.com. Ask about them on the ffrax forum too.

CALL911

That is an excellent idea/question!

Greed4Speed

Oh! or you could just visit the forums I mentioned and learn from guys who put their brakes to the limit on a regular basis.

Grims

Quick question, Why do speed bikes all use drilled rotors? Even my Katana has them, and bikes are known for their awesome braking.

spartyon

Bikes are also a lot lighter. My guess with the bikes would be because they are so light, the "weaker" drill/slotted rotors are fine. Plus they look a ton better than big flat chunks of iron. Bikes would be more for looks I would assume, the same as with cars.

Greed4Speed

Bikes also have much thinner and smaller rotors and smaller calipers and pads. Does this make them more performance oriented just because a bike has them?

Spartyon hit the nail on the head with weight. You're comparing hundreds of pounds to thousands of pounds.

RussStang

I would agree that cross drilling has no benefit on today's brakes, and will probably just cause you problems if you really beat the hell out of your brakes. However, I would not say slotted rotors are totally worthless. The slots aren't there to help move gasses, they are there to help keep cutting at the pad, and keep them from glazing. I can only speculate at the effectiveness of this, but I have heard from more than one source that slotting rotors can have benefits.

Greed4Speed

If you have the proper heat range of pad they won't overheat and glaze.

FASTFATBOY

I always thought(and I aint the brightest light in the hallway) that drilling/slotting was to help prevent brake FADE issues under continous use I.E. road racing /autocross type stuff....to help the gasses escape quicker and keep the pads/brake fluid cooler..or did I miss the boat and fall off the dock? IMO slotting only is the ticket for a heavy streetcar....but hey just my opinion.


TA-BODY..look at the size ratio of the rotor vs weight....BIG difference compared to a car. The force that can be applied to that bike rotor can stand it up on its front tire with little effort, bikes accelerate ALOT harder than cars(at least the 170 rwhp Busa under my carport does)



David

RussStang

I am not disagreeing with that. I was simply asserting that slotted rotors can how some benefits, regardless of how great those benefits may be, while drilled rotors are usually a liability.

Greed4Speed

I've heard they're a bit better in the rain too. It hasn't rained enough here since my new rotors for me to tell. Plus I don't know how my new pads would have done w/out slots in the rain either so there isn't a good comparison. IMO slots are still more for looks though. The only reason I have them is beause of the deal I got.