I have a bunch of mods on my C30 and overall it's driving really nicely but I still think the handling needs some fine tuning so I'm keen to hear suggestions.
Current mods are:
Limited slip diff
Bilstein B8 shocks/struts & Eibach springs
Elevate rear swaybar (25.4mm)
Whiteline anti-lift front LCA kit
Silver Project adjustable rear camber arms
Current tyres: Goodyear Asymmetric 5
Most of the time the car feels pretty balanced, and with the LSD I can throw it into corners with a fair bit of confidence. Obviously I'm limited by the grip of the front tyres and sometimes I get understeer if I go through a corner too fast but this is fairly predictale and not a big issue (and could probably be fixed by just going up to a better tyre).
The main issue is that in some circumstances the rear of the car feels very sloppy and not at all composed. Often I experience this going quickly around roundabouts, either when lifting off the power after accelerating hard or changing directions through the roundabout. However I find that this is less predictable than the understeer and it feels like the main restrictive factor in the car's handling. It doesn't really feel like a grip issue (that could be fixed with better tyres for example), more of a handling issue resulting from the suspension set-up but I'm having trouble pinpointing it.