Fair call and worth investigating, I wondered also if for some bizarre reason the traction control may have been creeping into the equation....a long shot I know but stranger things have happened. Thanks for your input. Yes well I guess I could be shifting later than I think but having driven many quick cars I reckon it's not too late, the thing is still making good power when I shift, not like it's over revving as such. Put it this way, if the problem IS the limiter...it's set too low. How do I know it's the gearbox? Well...without sounding like I know it all (coz I don't) I am in the gear manufacture/gearbox overhaul game so figure I have a fair idea. The car also has the usual diff gear/ drive spline play and the noise origin is discernibly separate. Cheers for your input.