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Discussion Starter #1
hi folks, im going to replace my stoptech rotors soon but what are the best alround brake pads for street use? also my rotors are slotted but stoptech do a drilled rotor is there any difference with performance between the two types of rotor??
 

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Are you running a Stoptech BBK?

Re pads,the EBC red or yellow stuff is great,I ran yellow stuff for 15k miles and they were superb compared to the OE textar pad.

From the tests ive seen having slotted or drilled discs doesnt really make a diffrence-just for show according to most people.
 

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Company Representative for Valley Motorwerks
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For the street slotted and or drilled is just eye candy. Try a set of ceramic pads, Akebono or otherwise. No discernable dusting as it will not stick to your wheels...
 

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It is recommended to stick with slotted rotors above all. Pads, I recommend carbotech. A quick search will result in a recently discussed brake pad question also.
 

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Are you saying this would be the best choice in your opinion for stock rotors?
Yes, no dusting and decent braking performance. I run them on everything I own with stock rotors.. it is one of the rare occasions where I'll recommend a part other than BMW OEM. My response was assuming he did not have a BBK - IIRC the Stoptech kit runs a Porsche shape pad, Akebono's may be available for them. I've run Carbotech Panthers on my old BMWCCA race car, I loved them. I have no experience with any of their street applications.
 

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Discussion Starter #8
hi thanks for the replys, yes its a stoptech bbk 355 x 32 with st40 calipers
 

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For the street slotted and or drilled is just eye candy. ...
there were some engineers from GM that wrote a paper on the differences between solid and drilled rotors below is a link to a summary of their paper:

eBay Guides - Drilled vs slotted rotors, what is better

here is a link to purchase the whole paper:

The Effect of Rotor Crossdrilling on Brake Performance

basically what they found was that drilled rotors did show an improvement on the street vs. solid rotors.

I also talked to a local race shop that builds and races BMW's and asked them if there was any advantages to either. what I was told was for the street stick with drilled and for the track slotted. I also asked about drilled rotors cracking and basically its a non issue for the street, on the track they could crack due to higher temps.

take this info how you wish I'm just passing on what I have read/heard. Personally as an engineer myself I trust another engineers research and also the opinion of people who race and test on and off the track.
 

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Company Representative for Valley Motorwerks
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there were some engineers from GM that wrote a paper on the differences between solid and drilled rotors below is a link to a summary of their paper:

eBay Guides - Drilled vs slotted rotors, what is better

here is a link to purchase the whole paper:

The Effect of Rotor Crossdrilling on Brake Performance

basically what they found was that drilled rotors did show an improvement on the street vs. solid rotors.

I also talked to a local race shop that builds and races BMW's and asked them if there was any advantages to either. what I was told was for the street stick with drilled and for the track slotted. I also asked about drilled rotors cracking and basically its a non issue for the street, on the track they could crack due to higher temps.

take this info how you wish I'm just passing on what I have read/heard. Personally as an engineer myself I trust another engineers research and also the opinion of people who race and test on and off the track.
We build and race BMW's, holding 2 regional championships and a multitude of wins with BMWCCA and NASA. That said... stopping power is more a function of tire adhesion and not the rotor and pad. Cars are equipped from the factory with ABS for this reason.. I run slotted on my US Touring / GTS car and find them to be more than adequate for even the toughest race conditions that we see. Our championship winning SpecE30's run factory solid eom rotors and have never had an issue with extreme braking. As I said in my previous post, if you can tell the difference on the street between drilled, slotted or solid rotors then please do not drive anywhere near me.

FWIW oem original brakes are more than adequate for street and hp track days. Again I reiterate that it is tire adhesion that determines overall braking efficiency, when the ABS takes over you're at the limit of the tires and not the brakes. Despite knowing this I run Brembo BBK's on my mostly street driven 500+ HP M3 and 4 pot brakes on my Mini Cooper because they look great and I track my cars.

After a hard day tracking my Cooper I never once felt brake fade. However after 2 laps in another equivalent car the OEM brakes were beginning to fail miserably. BBK's will not stop any car any faster than oem on the street. What they do is allow multiple hard stops by dissipating heat more quickly. Once the ABS is engaged it doesn't matter how big your brakes are or what type rotor you have.
 

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Cars are equipped with ABS from the factory because people don't know how to drive. if braking was all about the tires there would be no need for different compound pads. if brake cooling wasn't important people wouldn't need cooling ducts.

  1. For the sports sedan, the coefficient of friction was 21% higher for drilled rotors than standard front rotors at 340F and higher using 15 brake snubs at 62mph. The track simulated 124 mph fade test showed 37% better brake output for drilled rotors. The drilled rotor brake temperature was about 150 degrees cooler.
  2. For the performance car, the coefficient of friction was significantly higher for drilled rotors especially at high temperature.
  3. Wet braking at high pedal pressure was the same for drilled or standard rotors. Wet braking is not significantly improved by drilled rotors.
  4. Pedal force was much more consistent with drilled rotors over the brake temperature range. That is, to stop at the same deceleration rate, the driver does not need to modulate pedal pressure based on different brake temperatures. This reduces driver fatigue and improves brake response.
The authors also reported that drilled rotors prevent pad resin glazing on the rotor.

so what you are saying is none of the above information means anything and drilled rotors are just "eye candy"?
 

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Cars are equipped with ABS from the factory because people don't know how to drive. if braking was all about the tires there would be no need for different compound pads. if brake cooling wasn't important people wouldn't need cooling ducts.
so what you are saying is none of the above information means anything and drilled rotors are just "eye candy"?

How often do you brake hard from 124mph on the street? How often do you brake multiple times from 62mph with your rotors starting at a temp of 340deg F? I stand by my statements, they are in agreement with what you posted, you just don't see it.

Put **** tires on your car and brake hard, then go with a set of slicks do it again, how much more quickly do you think you'll stop with the better tires? Both setups will kick in ABS so where is your braking being limited? By the pads? The rotors? Not so if the ABS is engaged.. lock up is lock up. You placed extra weight with people who build race cars.. When you find out that I also build and win in racing all of a sudden it doesn't matter any more?

READ CAREFULLY - on a street car drilled and or slotted rotrs are JUST EYE CANDY. IF YOU ARE NEEDING THEM FOR THE STREET THEN YOU ARE DRIVING BEYOND WHAT CITY STREETS ARE DESIGNED FOR -IS THIS CLEAR ENOUGH? I never said that they aren't advantageous. If we were on a NASA racing forum it would be a different discussion... ever try to purchase racing pads? One of the questions among others is, are you on DOT R's or slicks? Why do you think this is?
 

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Agreeing with Valley here (but, hey, not disagreeing with anyone else), there were many discussions on BBK's for my old Coupe, and time after time, a specific disc and pad combination was recommended, in standard size and with standard calipers (Brembo 4-pots on the front). The reason being that one of the forum members of great stand (a regular 450bhp+ runner) often stated that with that combination, he could easily lock all 4 wheels at well over 100mph. The discussion would continue back onto BBK's, which is the best, can I make this one fit, when the reality was, barring appearance, there wasn't really a good reason for them. There were mods for improving cooling, SS lines etc. all bases were pretty much covered.

Now I know the M5 and the Fiat Coupe are very different cars, weight especially, but the point is that ultimate stopping power is often limited by the car's ability to actually grip the road, and not friction between disc and pad.

As a by-the-by, my car was fitted with the front discs from a later LE model which were drilled, and when I sold the car, I had lots little spidery cracks eminating from the drilled holes, and though I 'enjoyed' it, I never tracked it.

Edit - Had forgotten too that I got the ABS to kick in 3 figure speeds on the motorway after an Audi (typical) pulled out in front of me without any use of the mirrors, and that was on standard discs and pads, and decent tyres too.
 

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Cars are equipped with ABS from the factory because people don't know how to drive. if braking was all about the tires there would be no need for different compound pads. if brake cooling wasn't important people wouldn't need cooling ducts.




so what you are saying is none of the above information means anything and drilled rotors are just "eye candy"?
You got it - for street use, they are nothing more than eye candy.

Cars have ABS because people stomp on the pedal, exceed the adhesion of their tires, and skid. So, since the tires are the limiting factor in braking, and people can't pump the pedal fast enough (or at all), ABS was introduced.

Think of it this way: If the brake pads were the limitation, and not the tires, then there would be no ABS. It wouldn't be necessary since stomping on the pedal and keeping it down would be the fastest way to stop. This, however, is not the case.

Tracking is a different story since there are repeated high speed braking events, but on the street you might have 1 emergency stop, but if there is more than that then you belong on the track.

d-
 

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Discussion Starter #15
hi
ok so what is a good brake pad for the stoptech st40 brake kit folks ? ,i occasionaly hit high speeds but never track the car.
 

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hi
ok so what is a good brake pad for the stoptech st40 brake kit folks ? ,i occasionaly hit high speeds but never track the car.
I was always happy with the Ax Ults that came with my kit on Dave Z's recommendation. It may not be the newest, or "best", but very good street pad.
Regards,
Jerry
 
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