Unlikely, but is it possibly just some rubber marbles on your tyres that are flailing about and making contact with the wheel arch on cornering G's? Had something similar on my car a few times with soft semi-slicks.
RX-8 230 Bridgeported: Racing Brake Disks & 4 pot front calipers,Full Racing Beat (RB) SS Exhaust system,RB ARB's F & R,RB REVI intake,Tein MonoFlex Coilovers & front strut brace.
RX-7, KIMI 1, 1st Gen S2, Silver,1983 - SORN
RX-7, KIMI 2,^^Ditto - now sold
RX-7, KIMI 3, 1st Gen S3, Red,1984