Best is a matter of opinion. Personally I use R-1 Concepts zink plated cross drilled and slotted ventilated rotors and the pads they recommend and sell for their rotors. These are high performance rotors and pads and have the added benefit of not rusting due to the zink plating. They continue to look nice through the wheel spokes. Just a suggestion. Google R-1 Concepts on the net and at least take a look at them.
I don't just have them on my quad. I also have them on my Nissan P/U and the wife's Honda.
There are a lot of high performance brake pads out there. They all have their strengths and weaknesses. What kind of driving do you do and what do you want out of the brakes? Personally I run only cast iron discs and street/track pads. My current discs are just the stockers and I run Ferodo DS2500 pads which I love. They have a nice strong initial bite and resist fading when hot very well. They get a little better with some heat, but work very well when cold. They make a god-awful mess of the wheels with dust and tend to squeak a bit from time to time but they get the job done bombing up and down steep twisty mountain roads. My discs look like crap through the holes in the wheels if they've sat for any length of time. My car looks great disappearing into the distance near the end of a twisty downhill section of mountain road.
Here are some factors that all balance each other out - no pad does everything. Dusting, longevity, quietness, initial bite, high temperature fading.
I'm a fan of slotting but not of cross-drilling. Don't really see the point of cross-drilling on a car (on a bike you run a huge diameter rotor for leverage and heat dissipation, then drill it to reduce unsprung weight.) and I've had cross-drilled Brembo discs develop stress fractures around the holes.
It's important to note that none of this disagrees with Robert's setup at all - different needs require different setups. Spirited driving on the roads around here is extremely hard on brakes. Nice shiny rotors with no brake dust look great, and drilled discs definitely look awesome. Now if I could run ventilated discs with the stock calipers that would be AWESOME! So........
Robert - are you running ventilated discs with stock calipers?
Yep. Been using R-1 Concepts for the past 3 Nissan trucks without any problems. Admmittedly I do not do much high performance driving here in Midtown Memphis, TN.
When I installed the R-1's on the Alfa spider I installed new rotors and new calipers all the way around. Rotors and pads from R-1 and new calipers from Rockauto Parts, but I cannot remember the brand name off the top on my head. There are probably better brakes available out there but these suit me and I love the un-dusted and un-rusty looks of the calipers and wheels as a result of using this setup.
I got my cross drilled/slotted discs from Centerline, with Ferodo DS2500 pads, and SS brake hoses. It feels like dropping an anchor out the door when I brake hard in my S4 Spider. Those Ferodos just plain work, wet or dry.
Fortunately for guys like us who like to ponder engineering problems it is WAY more complicated than that, Bob. Unfortunately for us, a major part of the equation is an unknowable variable - the driver.
If you run street pads off one after another cold with a pro driver behind the wheel you'll find nearly identical stopping distances. If your Spider's brake system is healthy all of them will be easy to bring to the threshold of locking, making the suspension and tires the limiting factor. In fact a true race pad will perform the worst in this test - depending on the pad it may well NOT generate enough friction to lock them up when cold resulting in longer stopping distances. True race pads are not suitable for street use for this reason.
Similarly, if you put a novice driver in the seat and put them into panic situations they'll all perform the same as well - the novice will stomp the brakes as hard as he can locking up the brakes and taking the pads completely out of the equation.
If you have the pro do a series of maximum stops - say 60-0 - several times in a row then you'll start seeing differences in how the pads handle the heat. But you may get different results again if you start timing laps as consistency and pedal feel become more important.
So the differences come in the different parameters I listed earlier. Wear rate, pedal feel, cold performance, hot performance, dusting, noise, etc. Some of these parameters are mutually exclusive, so it's a big balancing act around these parameters. That's why it's so important to know the application and characteristics that a driver is looking for.
My Ferodo DS2500 pads are listed by Ferodo for both street and race application. They're listed in the race catalog only for endurance racing with relatively light-weight cars. On the street they have good but not great feel and bite when stone cold but get better with some heat, give a good pedal feel and will stand up to the heat of spirited mountain driving. On the track they give consistent performance across a range of weather conditions, give good pedal feel, perform well when completely cold and resist fade at higher temps. Good for an inexperienced driver doing track-day lapping - or even an experienced driver if he's careful not to push them too long and hard. They make a lot of dust though and can be a little noisy.
Next up in Ferodo's lineup is the full-race DS3000. They say all over "not suitable for street use". When full cold stepping on the brake pedal feels like stepping on a 2x4. They don't bite well at all and terrible pedal feel when cold. If you can get them up to temperature they wear fast and send off fountains of dust. But man, once they're nice and hot they grip fantastically and can take all the heat you can throw at them. You'll boil the fluid before you get pad fade.
I used to love EBC Green Stuff on my race bikes but hated them on my car. Great cold performance and really grippy as they get a little hotter. But then they just wilt under the heat with a lot of fade. Then they left horrible deposits on my rotors leaving me feeling like they were warped all of the time. Blech!
Unfortunately I don't have a lot of experience with more pure street pads so I don't have a good example there. But if you mostly just cruise you'll probably be looking for a pad with good bite and pedal feel when cold along with long wear and low dusting. You're not really going to be concerned with what they do when they get really hot since they'll probably never get really hot.
A lot of generalities in the video, but still a good explanation:
The article confirmed some of my suspicions about both pads and rotors. My Spider has unknown pads and stock rotors from the PO. From 100 MPH in and unscientific stop I can put all the force I can on the pedal and not get any lockup or fade but I do have some tire "squeal".
I kinda like it not locking up the wheels- this is with 165/65R14 Brigestone Potenzas with about 6 years of age and not a lot of wear. I will put the computer in it and check the G's and distance in a future post.