ONNETZ: What you just described is what every racer should do... experiment with new things. Some people however do not record/remember what they learn, and seem to forget what to do when at the track to make the car work like it did "that one day...". This is honestly where finding one type of car and sticking to it, can benefit a racer. I personally cannot swap from one car to another and make setup change efficiently. You would think that the same adjustments do the same thing from one car to the next, but it never seems to work that way. I had to play around with my diffs yesterday at the track too. High bite fresh laid blacktop that by the main had a sweeet groove. (thank you nitro TC) The blacktop was so fresh, my chair and pit table left dents in the blacktop where they sat. Most guys were running foams, but i was running CS27's until the groove came in. By the second and final qualifier, i had piddled with my front diff and noticed that the tighter i made it, the more the car would wiggle in and out of the corner. The front would squirm uncontrollably coming into the corner and on throttle out of the corner. All this time, the tires were squealing, more notably, the inside front tire on every corner. For the main i swapped my rear camber link, changed to double pink/double pink orange foams (same size at the CS27's .. 62mm), and went back to my original front diff setting. I qualified third in the A, two laps (9 second laps were average) off the TQ pace. TQ was on his own, but also on foams. In the main, the car didnt do any of the earlier mentioned wiggling, it just stuck and drove like a slot car... literally. I ended up putting two laps on the TQ driver, with the last three laps of the race a really nice battle for the third lapping... he wouldnt let me by! My fastest lap was a high 7. Foams make that much difference. ( i actually ticked the second place qualifier off in the first turn at the end of the straight coming into the sweeper, my car carried so much speed i checked up too slow and bumped him and spun him out )
Totally my fault.
The point is this. I think, after all of the setup work i did trying to dial in the car on CS27's, i realize they had reached their limit. Maybe some of the situations you are describing are symptomatic of rubber tires. Do you notice after a run if your tires "wrinkle" on the front or rear of the car? Wrinkled front tires lets you know the car is pushing, and wrinkled rears of course let you know its loose. All four should look smooth after a run. Unless you are of course running a compound that is too soft. In all honesty, you can tune the suspension (not the diffs) on a TC3 to get it to turn in so much, it will turn a small 3' circle with diffs, on power. I still dont like the way a car runs with a spool, and of course, the brake issue with a one-way. Heck, i guess it still comes back to driver preference. Ok, enough of my ramblings..