R31 Handling Quandary

[trebor]

I have a 2010 R31 (purchased new in 2013) racing in the World Formula class. I am about 2 sec per lap slower than I need to be to be up for a podium(!). Went testing yesterday and tried all sorts of chassis setups: Long vs short torsion bar, different front track widths (1 to 4 spacers inside the wheel). Camber pill set at max camber, camber pill set at min camber etc. etc.. My lap times were within 3/10ths no matter what the setup (55 sec lap).

There is no discernible difference between my laps when I look at Race Studio.

I changed one thing at a time and did 5 laps to get a reasonable average. I drove at maybe 95%, making sure I hit my marks consistently rather than overdriving. Maintained consistent tire pressures.

In the past with other chassis, a half front spacer change has transformed the handling.

So, is my chassis cracked or worn out? Is there something huge I'm missing?

Help!