A few more comments regarding the general setup, etc. etc.
Setup:
600# F, 800# R springs
-3F, -2R camber
0 deg toe front, .05 deg rear each side
Lots of rake, about 23" ride height both ends (18" tires)
245-40-18 F, 265-40-18 R, Trofeo-R's.
Swaybars (hotchkis) F- 2 of 4 (soft middle), R- 2 of 3 (middle)
Although I'm running a staggered tire setup, for no other reason than to preserve the street driving quality (no tramlining, etc.), the car still turns just fine. I pick up some understeer (about mid-way through a normal ~25 minute session) as the front tires get too hot, but some of that was learning the Trofeo's, and I was running them too high PSI up front....around 36 all around. The front needs to be 32-34, and rear needs to be about 34-36 hot.
Also, I'm going to put the rear bar on full stiff, and adjust shocks more next week, and this should help keep the car balanced all through the session. In fact, my buddy who is also a very good motorsport setup guy, gave the exact same analysis as I did after he drove the car. He thought the car had great balance until the got front tires too hot. I think ultimately, yes, I need to "take" a little grip away from the rear to help keep the front tires underneath the car, but that is fine. In no way did I feel like the car was "under tired" on a 265, with these sticky Trofeos. I could have been a lot faster had I not been waiting on the front of the car, waiting to get back to throttle. If I could rotate the rear more quickly, can get to throttle sooner, and ultimately be faster, all while preserving more front tire.
Sure, I can slap on more front tire (square setup), but that's not always needed. I don't want to lower the ride heights any further, or destroy the nice light weighting of the wheel. I also don't want to swap wheels. In short, my goal is to make a staggered tire setup work, without understeer, which clearly can be done with the help of an adjustable rear swaybar. I'm making this car truly a "jump in and go to the track" car.
However, if you have solid rear subframe bushings, I have no idea, even with a square setup, how people track this car without an adjustable rear swaybar. On my E46 with square 275 setup, I still ran the rear turner bars on full stiff. This E92 chassis feels no different to me, albeit a much stiffer chassis shell. Not having that adjustment at the rear of the car is a real disservice to yourself.
Regarding tires....guys, these Trofeo-R's are the real deal. They are sticky, but still offer a lot of feel. They aren't cheap, but you get what you pay for. Hands down the very best track tire that can be driven to the track, and I like that they come in stock 18" sizes for the car. And if absolutely needed, I could always use a 265-35-18 front, for a square width setup (not diameter). I like to run my cars with staggered tire diameters (with exception of a miata). The rake helps the car turn, and the taller rear tire adds progressiveness to the rear, so you can really stiffen the chassis up to add balance. Shorter front diameter gives steering great response. Just my preference.
I'll follow up after next week's test of the new chassis settings. I think it's going to be just about right
