Drilled/slotted rotors

[4mulacar]

Like your video jtower! I find it interesting in the first 3 minutes the differential heating of the rotor surface, for example at 1:16 you see just the inner surface of the rotor heating,at 1:27 heat bands appear on the inner and middle circumfrentially, at 1:46 at your hardest braking in T14 wider bands than at 1:27 but cooler inner and outer bands. At T1 inner and outer bands are glowing but the center area is cooler, however at 2:12 center cool area is minimizing. Even though these are not infrared camera shots with a camera that can be set for emmistivity there are some interesting visual data points. By 3 minutes into this the rotor has normalized and the heat pattern is no longer easily discernable hence a calibratable infrared camera would be required to discern the effects.
I know from racing experience after about 2 laps on most tracks my brakes are hot enough for driving in anger, however your post has really got me thinking about how well I have actually optimized my braking system. A call to my local friends at Fleer is in order on my trip to Portland this weekend. Thanks for posting the video it really made me think and that I enjoy.

It is definitely hard to draw any finite conclusions without further testing of this to quantify some of what I saw but I may PM you after this weekend of testing to ask you about some of what I saw and you can enlighten me on some of my questions.

 

[jtower]

Like your video jtower!

it's not *my* video, just one that i stumbled across recently. but glad you like it

 

[VBNSX]

i have to admit.. I never thought I could be so amazing watching a metal disk spin around :tongue:

 

[Liquid]

I have the NSX-R slotted rotors. They look good and basic physics tells you they will handle heat better. Agree it isnt needed for street, but it can't hurt and in the event you decide to try a track event they are there.

I figure if there were no value at all Honda wouldnt have put them on the R. You cant exactly accused the R of having "dress up only" parts!

Details on these (Cost, NA1 or NA2, 2 piece, etc.)? Did you purchase through your Acura dealer?

 

[lightguy]

By the way; what ever happened to dimpled ?

Mt thoughts on rotors; Its better to cool them down than increase mass as mass increases unsprung weight and slows acceleration.
The cooling ducts/foils offered by standard suppliers help but are no where near what real cooling ducts achieve. Read Carrol Smiths thoughts on proper ducts in his series. In them he states that a blocking plate is needed on the inside "eye" of the rotor to force air through the slots not just spilling out everywhere. And of course the duct attached to this plate should be as big as possible.
He also talks of machining two straight parallel cleaning slots in plain rotors to get an effective result as opposed to radial slots.
Anyone racing on even a novice level must own (and read) his collection.
The best there is.

IMO drilled or ones with cast holes are for show and that is just fine on street cars but are not a cost effective solution in real racing because of the lowered life span.

 

[e.pie]

if you track your car at all drilled rotors WILL crack, it's not a mattor of if but when

blanks or slotted are the only way to go

 

[FXMDBilly]

By the way; what ever happened to dimpled ?

Mt thoughts on rotors; Its better to cool them down than increase mass as mass increases unsprung weight and slows acceleration.
The cooling ducts/foils offered by standard suppliers help but are no where near what real cooling ducts achieve. Read Carrol Smiths thoughts on proper ducts in his series. In them he states that a blocking plate is needed on the inside "eye" of the rotor to force air through the slots not just spilling out everywhere. And of course the duct attached to this plate should be as big as possible.
He also talks of machining two straight parallel cleaning slots in plain rotors to get an effective result as opposed to radial slots.
Anyone racing on even a novice level must own (and read) his collection.
The best there is.

IMO drilled or ones with cast holes are for show and that is just fine on street cars but are not a cost effective solution in real racing because of the lowered life span.

Performance Friction Brakes (PFC) uses dimpled rotors on their street and race applications.

Dimpled rotors work quite well and do not have the stress risers that lead to cracks like drilled rotors while not having the cheese-grater effect that increases pad wear in slotted rotors.