The 91C was driven by two other drivers in competition. Truesports entered a second car for Geoff Brabham to compete at the 75th Indianapolis 500 in 1991. Brabham retired from the race with an electrical fault. Robco, which previously participated in Toyota Atlantic and Indy Lights, graduated to Indy cars in 1992 with the Truesports 91C powered by the Judd engine. The outfit entered 9 races with rookie Brian Till and scored 8 points, but did not continue onto the 1993 season.