Is it safe to track these rotors?
12-05-2002, 02:42 PM
#31
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As for porsche ceramic brakes go, they have outstanding heat capacity and cooling efficiency to take abuse and last longer than conventional brakes. To all their own.
my 0.02
12-05-2002, 02:51 PM
#32
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This post brings back many memories .
To drill or not to drill .
Cast iron is not a good material to have holes drilled or cast in , where the pad runs . The heat generated under hard use will always start cracks , at the holes . Because the structure of the disk is weaker at the holes , when a disk fails it will be at the weakest point .
The reason that Spoon makes these rotors , is that people want them . They are directional rotors that are not left and right specific? ( engineered by who?)
If you are going to use your car hard on the track I would definitely recommend two piece racing rotors . ( not look-a-like offshore cast one's [ no Chinese or Taiwan ])
People wonder why our rotors cost so much , yes all our rotor are thermally treated . our hats are Forged , we supply stainless steel bushings to allow for expansion of the rotor and all the bolts are safety wired .
We are working on a Steel composite rotor that will run 30% cooler than the cast iron racing rotor that we supply in our kit now . It will also be drilled for weight reduction.
Brad
Pinnacle Braking Systems
To drill or not to drill .
Cast iron is not a good material to have holes drilled or cast in , where the pad runs . The heat generated under hard use will always start cracks , at the holes . Because the structure of the disk is weaker at the holes , when a disk fails it will be at the weakest point .
The reason that Spoon makes these rotors , is that people want them . They are directional rotors that are not left and right specific? ( engineered by who?)
If you are going to use your car hard on the track I would definitely recommend two piece racing rotors . ( not look-a-like offshore cast one's [ no Chinese or Taiwan ])
People wonder why our rotors cost so much , yes all our rotor are thermally treated . our hats are Forged , we supply stainless steel bushings to allow for expansion of the rotor and all the bolts are safety wired .
We are working on a Steel composite rotor that will run 30% cooler than the cast iron racing rotor that we supply in our kit now . It will also be drilled for weight reduction.
Brad
Pinnacle Braking Systems
12-06-2002, 03:48 AM
#33
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Hey Brad - do you make a replacement rotor that works with OEM calipers? I'm thinking about going that route for track days and then swapping back to OEM rotors to stay in the stock autocross class. Also, would such a system work with stock components in the rear? TIA
Based on my personal experiences, I agree with Mike, drilled rotors crack! I've never observed drilled rotors on street cars that were used on the track that didn't crack. Does ANYONE have data to counter this statement? I agree that composite rotors and two-piece racing rotors may work when drilled. I'm talking about rotors for production cars.
Based on my personal experiences, I agree with Mike, drilled rotors crack! I've never observed drilled rotors on street cars that were used on the track that didn't crack. Does ANYONE have data to counter this statement? I agree that composite rotors and two-piece racing rotors may work when drilled. I'm talking about rotors for production cars.
12-06-2002, 09:16 PM
#34
Originally posted by Mike Schuster
Really if Spoon will replace rotors with cracked holes like these then I probably should start using them! Cracks always start at the holes, if any, and I always end up replacing my rotors due to cracks rather than wear. So free rotors for life!
Really if Spoon will replace rotors with cracked holes like these then I probably should start using them! Cracks always start at the holes, if any, and I always end up replacing my rotors due to cracks rather than wear. So free rotors for life!
.Utah
P.S. If you do have a failed rotor please feel free to send it to me and I'll tell you why it failed. Where else can you get free wet metallography and free electron microscopy in an aerospace failure analysis lab? With as cast holes and proper stress relieve the rotor should outlast the pad, and usually the car, without exception.
12-06-2002, 10:28 PM
#35
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Originally posted by Utah S2K
Stop buying cheap rotors and then the cracks won't start at all.
Stop buying cheap rotors and then the cracks won't start at all
.
In my case I think rotors crack because I overheat them. I believe Honda did not design the brakes for track driving. So you should expect to have trouble. If you aren't then learn to drive faster.
Cracks usually start as faint surface cracks oriented the the radial direction. Here is a picture of what happens if I continue to drive with these faint cracks - they get longer and deeper:
If I keep driving then eventually this happens:
If you look at a budget rotor cracking is actually not a major cost issue. Per day at the track I spend roughly $100 on tires, $100-200 on pads, $250 for registration and maybe $50 for rotors.
12-12-2002, 06:44 AM
#36
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I did some research on why Porsche uses holes in their brake rotors. The 911 marketing brochure says
"The front and rear brake discs are cross-drilled to improve braking in the wet. The brakes respond better because the water vapor generated under braking can be released more efficiently."
Although you can get to threshold in the wet easily (ie, ABS activation), it may well be that it takes the car longer to do so in the wet with solid rotors than it would with holed rotors. I had not previously considered this possibility.
This idea would be easy to test. Install a holed rotor on one side of the car and a solid rotor on the other. In the wet see which side goes into ABS consistently first, and measure the time difference. This would tell you roughly how many feet of braking distance, if any, the holes provide.
As I said, in my experience on the track holes do crack, but they may well provide a safety advantage in the wet.
"The front and rear brake discs are cross-drilled to improve braking in the wet. The brakes respond better because the water vapor generated under braking can be released more efficiently."
Although you can get to threshold in the wet easily (ie, ABS activation), it may well be that it takes the car longer to do so in the wet with solid rotors than it would with holed rotors. I had not previously considered this possibility.
This idea would be easy to test. Install a holed rotor on one side of the car and a solid rotor on the other. In the wet see which side goes into ABS consistently first, and measure the time difference. This would tell you roughly how many feet of braking distance, if any, the holes provide.
As I said, in my experience on the track holes do crack, but they may well provide a safety advantage in the wet.
12-12-2002, 07:01 PM
#37
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Yes we can make two piece racing rotors that fit the stock Honda system . Our rear ultra light weight rotor does .
The super rotor that we are working on now is being designed to be able to be machined to fit the stock system also . Because this rotor will have steel wear surfaces , we will cross drill to reduce weight.
Brad
Pinnacle Braking Systems
The super rotor that we are working on now is being designed to be able to be machined to fit the stock system also . Because this rotor will have steel wear surfaces , we will cross drill to reduce weight.
Brad
Pinnacle Braking Systems
06-08-2003, 04:34 PM
#38
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I'm ressurecting this thread, as to my dismay, my OEM rotors show the same type of cracks as the ones I posted above, after just a couple of days of track outings.
Frankly, the spoon rotors don't seem to have fared much worse. The problem must lie elsewhere. I have used brakeman #3, Panther XP, Honda OEM, Honda modulo pads and others but I guess it's not a pad problem. We probably need more cooling.
Is anyone reliably tracking their cars on high speed tracks (top speed 200km/h+) without cracks developing? If so what pads, brakes, rotors, calipers are you using?
Frankly, the spoon rotors don't seem to have fared much worse. The problem must lie elsewhere. I have used brakeman #3, Panther XP, Honda OEM, Honda modulo pads and others but I guess it's not a pad problem. We probably need more cooling.
Is anyone reliably tracking their cars on high speed tracks (top speed 200km/h+) without cracks developing? If so what pads, brakes, rotors, calipers are you using?
06-08-2003, 05:14 PM
#39
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I track my car on the Nurburgring, which can be a hard braking track, but you will see speeds of 220+ as well (maybe 280 on a bike!). There are several sections where you will go a few km without braking, so heat cycling can be an issue. Each lap takes at least 8 minutes of concentration, and I always drive around the town a bit for a cooldown after each lap.
So far, I've not noticed any cracking, just pad build up, leading to vibration. For some reason, the rear pads are wearing out a bit faster than the fronts, and the rear rotors are quite a bit hotter.
I've used the stock pads (faded after a few laps), EBC Greenstuff v4 (good pad, lasted 46 laps), and now the Ferodo DS2500 (good feel), with stock rotors all round. Front rotors are new. Stock calipers too. ATE superblue brake fluid, which was much better than the stock stuff.
///Robin
So far, I've not noticed any cracking, just pad build up, leading to vibration. For some reason, the rear pads are wearing out a bit faster than the fronts, and the rear rotors are quite a bit hotter.
I've used the stock pads (faded after a few laps), EBC Greenstuff v4 (good pad, lasted 46 laps), and now the Ferodo DS2500 (good feel), with stock rotors all round. Front rotors are new. Stock calipers too. ATE superblue brake fluid, which was much better than the stock stuff.
///Robin
06-09-2003, 05:25 PM
#40
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Is anyone reliably tracking their cars on high speed tracks (top speed 200km/h+) without cracks developing? If so what pads, brakes, rotors, calipers are you using?
You're not alone Luis. My OEM rotors are good for about 3-4 hours of hard track use. In fact the rotors don't even look that worn out before developing cracks. Pads: Hawk blue; Carbotech XP, P+; and Brakeman #3's.
You're not alone Luis. My OEM rotors are good for about 3-4 hours of hard track use. In fact the rotors don't even look that worn out before developing cracks. Pads: Hawk blue; Carbotech XP, P+; and Brakeman #3's.