QUOTE (StanIROCZ @ Sep 25 2013, 09:39 PM)

Even when just the driver mod makes me faster every session? Seriously, over the past year I get faster almost every session without touching the car,,,, just growing ball sack (with a couple exceptions). I could play with my spoiler angle or adjust my front koni's,,, but then I wouldn't know if I got faster because of the tune or driving. I assume your statement is based on the assumption that the driver is using 100% of the cars potential.
In my mind (and everyone tunes differently) you pull enough data to effectively and subjectively view a change as a positive, negative or neutral. More importantly, you're bright enough to do a debrief after a session to help evaluate the performance.
SO...If you were my student and went to a trackday solo, I'd tell you to do the first session or two with everything the same (equalize air pressure) and get a baseline time. After the second session you'll sit down for 5 minutes away from everyone either looking at a track map or watching a replay of a lap. Dissect each corner into entry, mid, and exit and as you do the lap and prioritize what ONE BENEFIT would help you the most. Let's say it is on entry and the car is simply not getting INTO the corner as quick as you think is possible. Mid and exit are okay. So, we now know the result we need (better turn in) and we know to always begin adjustments on the end of the car that is NOT working until you run out of adjustments and then AND ONLY THEN can we "do damage" to the opposite end of the car to achieve balance. So, in the front we need more turn in. Let's ponder that. First, look at the tires. Are they rolling over too much and bumping pressure might help. OR are they not rolling enough and we're overinflated? Does the turn in suffer on both directions? Can we back off on the sway bar end links to let the car roll and bite a bit more? Can we make a damper change?
(Note: Neil has a great chart in his book, also this is damn handy too:
http://www.amazon.com/Carroll-Smiths-Engin...er+in+my+pocket )
So let's say the tires looked great and you backed off on the sway bar end links. Initially you had them totally snug with bulging little bushings, and now you've loosened them 5 rounds a side where they practically rattle (noise does not slow you down, FYI).
Then on the third session one of three things happen. You get faster, slower or stay the same. If you get slower....time to ponder: Assuming you drove well and had clear track, did the setup change NOT help the turn in? Look at your data on turn entry....is the degrees per second turn-in not as good as before? Or time stayed the same? Did the turn in help but it caused you issues on mid or exit now? Or, most likely, you got faster...and you can debrief yourself and say "self, the setup change helped, the car rotate into the corner better and i went faster because of that and because I had more confidence in the car and I'm simply driving better". Now you get to debrief AGAIN pondering 'what ONE change could I make to help my lap times?". And it starts over again. If you're unsure, re-tighten the sway bar end links and drive another session. More than likely you'll say 'fork that!!' and you've successfully learned a quick little trick that can help your setups in the future.
Folks who are vested enough to not only want to go faster but are willing to methodically look at the car, do debriefs, make track notes and also keep records of setups and changes are typically folks who can self-learn assuming they've at least got a baseline procedure to follow. Most any procedure will work and the one I outlined above is the one I use, taught to me by Neil. My last outing I did three sessions flip flopping changes to double verify that they worked.
Now, sometimes you've got to take a sharp car (setup wise) and 'dumb it down' so the driver has a stable car to 'get up to speed' in. Then, when the driver has caught up to the car, we can begin to re-sharpen that car and the driver goes really fast. Now, the setup from step 1 and step 10 ended up being the same, but we had to get the driver up to the ability to drive the damn thing and that took 9 steps. I've had a student who showed up with a prepped c5Z06 on hoosiers and after one session he bolted back on the streets because there was no way he was getting to the level of the car on purple crack. He could almost reach the car's level on streets, but hoohoos were out of the question at that point. A few track days later and we're again ready to bolt on the hoosiers and begin to work our way towards reaching the limits of that combination.
Long and winded and hopefully you followed that....
but that's my .02
Costas
cars and such...