I'll try and give a pretty detailed explaination... I have been curious as to find a way to explain why the pistons work the way they do. I didnt really quite understand it untill I learned more about fluid dynamics in physics class last week LMAO. This will help me review a bit for my test as well.
It's all about when the shock oil molecules change from laminar (smooth) flow, to turbulent (not so smooth) flow. When the shock moves at a slower speed, the oil flowing through the piston holes and the outside edge of the piston is fairly laminar. This means the fluid is flowing is fairly straight streams of oil and the molecules arent hitting each other in so many random directions.
Then there is a point where if the shock piston travels fast enough, oil's flow goes from laminar to turbulent. When the flow is turbulent, it "packs" up because it's harder for all the oil molecules to pass through the holes when they aren't in uniform lines. Think of it as a bunch of crazy after thanksgiving shoppers trying to get through a mall door
So the piston has a BIG effect on how easily the oil goes from laminar flow, to turbulent flow. A simple, and very general way to compare pistons is to take the area of the holes in the piston.
So if you have a piston with 3, 1.1mm holes:
3.14 * (1.1mm/2)^2 = .94 square mm, the cross sectional area of one hole
then multiply it by 3 to get the total area of about 2.84 square mm
Compare to a piston with 2, 1.2mm holes:
3.14 * (1.2mm/2)^2 = 1.13 square mm for one hole
then multiply by 2 to get the total area of about 2.26 square mm
Alright... So as we can see, the 1.2mm 2 hole piston has less area for the oil to pass through. This would make it easier for the oil flow to be turbulent when the rate of which the pistons moves gets faster. This is why it packs up more than a 3 hole, 1.1mm piston. Thats pretty intuitive, but now you guys know all to cool freakness behind it haha.
Anyway, the 1.1mm 3 hole pistons have less pack. With a thicker oil, they have the same slow speed dampening feel, but they pack up less when you REALLY throw the car into the corner (moving the shock piston quickly). I feel in most conditions it gives a little more grip, and seems more balanced throughout the entire corner.
The 1.2mm 2 hole pistons combined with a slightly thinner oil will have similar slow speed feel, but when you start moving weight around the car quickly, it packs up really quick and prevents the car from rolling. This can reduce traction a bit, and make the car a little inconsistent in low grip conditions.
When the grip is REALLY high, as in foam tire carpet racing, sometimes the effects can be different. More pack sometimes creates more grip, while less pack creates less grip. I think it's mainly because there is so much available traction, it just pushes the tires into the ground harder, rather than rolling. Thus... it develops more grip with more pack, and less when the car is allows to roll.
I hope that wasnt to confusing for everyone, but I figured it might be kind of cool to know the reasoning behind what we feel on the track.