tc3Guru, I believe BMI is still working on a prototype chassis for the TC4. Some extra stuff needs to be on the chassis, compared to the TC3 one, to take care of the camber rod mounting, as it is not part of the shock tower like on the TC3. I am looking forward to seeing BMI's setup too, as even with the graphite parts, I feel the TC4 has too much torsional flex in the chassis.