Hi, I guess this can serve as my semi-official introduction to the N2 online community. My name is Mike Faillace and I own and operate MDM. We're based just outside of Philadelphia and we've been around for over 10 years serving the track day and racing community and I've been a Pirelli man for as long as I've been involved in motorcycles. First, as a track day rider and then as a racer and now, for the past several years, as the official race tire vendor for this region. I've won a lot of races and championships on Pirelli tires and have worked with a lot of racers and track day riders over the years and have been fortunate enough to have my name associated with 1000s of race wins and hundreds of championships. I have crew chiefed for many CCS racers, run pit crews for a number of Daytona 200s and have most recently served as crew chief for Xavier Zayat and Brandon Paasch and a number of other very talented young (and old!) racers in addition to working at the pro level on occasion (a few times for N2's very own Eziah Davis). My shop's specialty is chassis and suspension and, of course, Pirelli tires.
That said, let's answer some questions you may have.
Exact psi recommendations will vary based on track and conditions and rider preference and pace. In general, I've found that most riders are running fronts too low when left to their own devices or internet or Facebook information. Pirelli offers general guidelines for pressures much in the same way that some suspension tuners will offer you sag numbers; they are often very subjective. I have a few expert racers that are running the fronts as "high" (I put that in quotations because it's only "high" if you are basing your idea of a starting point on an incorrect number) as 38 psi. The answer is (almost) always give the tire (or the suspension, for that matter) what it needs. When riders complain of a motorcycle that's difficult to turn while trail braking, it is usually because they are running an under inflated front tire. The profile of the tire is distorted because it doesn't have enough air in it to maintain the profile under load.
As a general rule of thumb, correct pressures for most track day riders will be 33-36 psi in the front and 24-26 psi in the rear for most compounds on most tracks on most days. Pressures should be set hot (meaning hot on the warmers after 45 minutes to an hour of bake time) at 170-180ºF. Pressures set on the warmers yields a repeatable result. It is worth noting that having an accurate tire gauge is very, very important. Many riders and racers are checking the pressure on a $400 set of tires with a gauge that costs less than their lunch and is about as useful as a ham sandwich when setting pressures. Get a good gauge. Check the gauge you're using now. And checking your pressures is free; do it often. Your tires will thank you.
Compounds have an operating temperature range they are designed to work in. Again, as a general rule, the colder ambient and track temps are, the softer a front and the harder a rear compound you want. In warmer temperatures, a harder front and a softer rear will work better. Pirelli offers fronts in SC1, SC2 and SC3 compounds and rears in SC0, SC1, SC2 and SC3 compounds. We often refer to compounds by colors as well. SC0 is white, SC1 is blue, SC2 is green and SC3 is yellow. A fast rider or racer will almost always want the SC1 or SC0 rear. Slower or more intermediate riders may want to trade the outright grip of the SC1 for the longevity of the SC2 or SC3. Grip and longevity are inversely related; the more grip you have, the quicker the tire will wear out. The less grip you have, the longer the tire will last.
The fronts are a bit more subjective. In general, faster riders will get along better with the SC2 or SC3 fronts while the SC1 front is more of our utility workhorse tire (it can do pretty much anything). Tuning the feel of the front with pressure is very important and there is a lot of overlap in performance and feel. For example, most riders would not be able to tell the difference between an SC1 front run at 36 psi and a SC2 front run at 34 psi. The faster a rider is, the more important it is to isolate which compound and psi gives them the best feel and confidence.
In general, the SBK product is a slightly stiffer carcass when compared to the DOT tire. The siping (or tread) of the tire is a break in surface tension on the DOTs and allows them to deflect more under load than the SBK tires. So, in general, we'll run the DOTs 1psi higher than the SBK. There is a lot of overlap in performance between the fronts and the carcass of the tire can be tuned (within reason) by adjusting pressure without compromising performance and outright grip.
I have attached the official fitment guide as provided by Pirelli which can be used as a general guide and I'll try and monitor the board as best I can and be responsive to questions regarding the tires. We have a variety of compounds and sizes available to suit different riding styles and Pirelli invests a lot of resources in developing the tires and evolving the technology and information we have available to us.
There's a lot more info we can get into regarding warmer usage and compounds and heat cycles and how a tire actually creates heat and things like that, so I'll let you guys decide what you'd like to know and we'll go from there.