I only double stuffed Tamiya 60D's. I used a Sorex C firm insert complete against the tyre and then used a Tamiya firm foam insert. It takes a bit of practice to get it to sit right.
There is an article on the
http://www.rc-mini.net/ concerning this process.
Dan,
Hate to diappoint you, but you will most probably white wash us all next weekend at the state titles.
Speed secrets be smooth and consistant.
Drifting101,
I have my Transponder mounted on the side of the rear chassis facing out, just behind the battery mount, opposite side to the motor.
Later
Calvin.