Brembo and Racing Brake don't offer front cross drilled rotors. Anyone else out there other than KVR that offers front cross drilled 1 piece rotors for a 91 NSX?
Front Drilled rotors
- Thread starter dablackgoku1234
- Start date
Try Powerslot.
Whats wrong with KVR? Terry Gosse is the shit!
Whats wrong with KVR? Terry Gosse is the shit!
Well, doesn't this indicate to you they may have a reason for not offering these?
My view on x-drilled:
If x-drilled OE discs (like on Porsche), nothing wrong, as these are usually cast with holes, not drilled.
If you want x-drilled for appearance and road use, than nothing wrong with x-drilled.
If you want performance as in track use: don't get x-drilled! Just about every responsible brake disc supplier will advise against these in aftermarket version as you risk cracking under track conditions.
(I have had it happen once too on the track, never will buy x-drilled again)
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Hmm, I bought drilled Brembos for the 350Z before.
Nothing wrong with KVR, just seeing what options I have. I understand that cross drilled rotors have a bigger chance of failing, but I wont be tracking the car. Just want a better look since I have to change my rotors soon, but want to stay with a reputable company. Would there be a negative effect running different brands in the front than the rear?
Stoptech has beautiful 2 pc. drilled rotors.
If you want performance as in track use: don't get x-drilled! Just about every responsible brake disc supplier will advise against these in aftermarket version as you risk cracking under track conditions.
(I have had it happen once too on the track, never will buy x-drilled again)[/QUOTE]
+1 on the above- even some spirited canyon driving can crack/warp drilled rotors (done it on several cars). if you want the benefit of gas release and pad cleaning then go for the slotted rotors, not drilled.
(I have had it happen once too on the track, never will buy x-drilled again)[/QUOTE]
+1 on the above- even some spirited canyon driving can crack/warp drilled rotors (done it on several cars). if you want the benefit of gas release and pad cleaning then go for the slotted rotors, not drilled.
I agree with drilled rotors. I run slotted on all 4, supplied by KVR. I'm not sure what the quality of the one piece are, but the 2 piece rotors they offer are well engineered and gorgeous.
There's little evidence, if any, that cross-drilled rotors offer better performance. As others have noted there is a great deal of evidence to suggest drilled rotors actually perform worse that both plain and slotted rotors and are more susceptible to failure than both plain and slotted rotors.
While there are many performance cars that come equipped with drilled rotors you won't be finding drilled rotors on competitive race cars (where it really counts). NASCAR and all Formula series exclusively use slotted rotors and have done so for as long as I am aware. The consensus is that drilled rotors are really for looks only.
As a side note, if one does choose drilled for looks be sure to purchase rotors that have the holes cast in them as opposed to the holes drilled into the rotor after casting. The latter are much more prone to failure. rsevo6 also mentioned this.
While there are many performance cars that come equipped with drilled rotors you won't be finding drilled rotors on competitive race cars (where it really counts). NASCAR and all Formula series exclusively use slotted rotors and have done so for as long as I am aware. The consensus is that drilled rotors are really for looks only.
As a side note, if one does choose drilled for looks be sure to purchase rotors that have the holes cast in them as opposed to the holes drilled into the rotor after casting. The latter are much more prone to failure. rsevo6 also mentioned this.
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It would surprise me if anyone thought the drilled front rotors and plain rear rotors that the Mercedes S class leaves the factory with improve the car's looks.
Here's an interesting question for someone who knows about thermodynamics: by removing material through drilling, we are reducing the mass of the heat sink, meaning it cannot absorb as much heat and will overheat more quickly, right? But, aren't we also increasing the surface area of the rotor that is exposed to air?
It's been a while since 8th grade math, but I guess the question is: if you think of each drill hole as a cylinder, you've removed the top and bottom of the cylinder and have exposed the inside wall. Is the area of the inside wall greater than the area of the top and bottom?
Let's say we drill a 6mm hole. The area of the top is Pi*r2, or 3.14(3*3) = 28.26 sq. mm. Multiply by 2 to get the surface area lost by removing the top and bottom = 56.52 sq. mm.
Now we just need surface area added by exposing the cylinder inside wall. Area of the cylinder is pi*diameter*height. Assuming a 21mm thick rotor, the area is 3.14(6)(21)= 395.64 sq. mm.
So, by drilling a 6mm hole, we are increasing the exposed rotor surface area by 395.64-56.52= 339.12 sq. mm. Structural issues aside, could this be why drilled rotors were tried in the first place?
It's been a while since 8th grade math, but I guess the question is: if you think of each drill hole as a cylinder, you've removed the top and bottom of the cylinder and have exposed the inside wall. Is the area of the inside wall greater than the area of the top and bottom?
Let's say we drill a 6mm hole. The area of the top is Pi*r2, or 3.14(3*3) = 28.26 sq. mm. Multiply by 2 to get the surface area lost by removing the top and bottom = 56.52 sq. mm.
Now we just need surface area added by exposing the cylinder inside wall. Area of the cylinder is pi*diameter*height. Assuming a 21mm thick rotor, the area is 3.14(6)(21)= 395.64 sq. mm.
So, by drilling a 6mm hole, we are increasing the exposed rotor surface area by 395.64-56.52= 339.12 sq. mm. Structural issues aside, could this be why drilled rotors were tried in the first place?
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you are absolutely correct BUT by drilling that hole we just increased a local stress concentration around it by 600% (no bs)- thats why they crack.
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I too have never seen a drilled rotor on a race car.
OTOH, the OP stated that he wants them for looks only. IMO, the slotted rotors look more racey though.
Here are a couple:
- Ferrari F355 Challenge race car
- if it counts, the 2009 Porsche 911 GT3 RS comes standard with a roll cage and drilled steel brake rotors (pictured are the optional drilled ceramic rotors)
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The Ferrari ones were likely done back when that was still thought to help, not hurt. As for Porsche, are you SURE they aren't cast?
No, I don't know how the holes were made. On the German Porsche website they just say, "The steel rotors are large: 350 mm diameter front and rear. They have holes and are internally ventilated..." (Die Stahlbremsscheiben sind groß dimensioniert: mit 350 mm Durchmesser vorne und hinten. Sie sind gelocht und innenbelüftet...). They don't mention whether the holes were cast; whether they were drilled, chamfered, and then heated in an oven to relieve internal stresses; etc. What's the generic word for rotors with holes?
cheese:wink:
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