Croc,
Sorry, missed your post somehow.
After several weeks of communicating with Roger Kraus (Roger Kraus Racing) and Rich (Bogart), I (we; collectively) came up with a 16” wheel with a smaller center designed to: a) lighten the wheel; and b) to pull as much as possible of the rotating mass inward as close as possible to the center of the wheel. This quest for wheels/tires all came about as a result of my having added 50-plus HP to the rear wheels this winter. The initial drive, after dyno tuning, suggested that this change had given rise to the need of another . . . . More grip. While my car can be driven very easily with its progressive throttle linkage, it was pretty obvious that to utilize the additional power to its fullest potential out of a turn would require rethinking getting it to the ground.
Last year, I ran (both front and rear) Avon 10.7x21.5x15 A11 compound tires on low-dollar budget 15x10 aluminum wheels from Summit Racing, all with a 4.5” backspacing. While this combination worked relatively well when mixed with my novice driving skills (or lack thereof), I still felt like I was leaving something on the table; and this was before making the engine mods. After many conversations with Roger regarding sidewall height and deflection, grip, usable power coming out of corners, wheel width, slip angle, as well as some irregular tire wear I had experienced with my current setup, we came up, first, with slick sizes for the front and the rear; Avon (A11 compound) 10x23.5x16 and 11x23.5x16 respectively and then wheel widths to accommodate; 10” front and 12” rear.
With Roger’s brain picked and his wisdom tucked neatly in my back pocket, Rich at Bogart began working with me to come up with, what we both felt would be, a suitable wheel combo for the car. What we ended up with (final decision made yesterday evening) was a 16x10, 4.5” backspacing for the front and a 16x12 for the rear with a backspacing that will end up somewhere between 4 and 4.5 (min to max). Since the current steering geometry seemed to work very well with the 10” wheel with a 4.5” backspacing, we decided that that part of the equation shouldn’t be monkeyed around with.
So, having rambled on here, the proof will ultimately end up being in the pudding.
This sorta' goes along with the handling thread, but don't necessarily want to put this info there . . . . at least not right now as that thread is rolling along pretty well with suspension setup.
:svengo: