I use to run the Fantom .21 a well great engine great raw power, Im still running the Fantom works pipe on the car at the moment.
There would be a market for a pipe that lets you run a .21.28 in a 1/10th chassis as a pipe is hard to come by this is your MGT monster Truck pipe in a Schumacher fusion.
This one above is a Fantom Works pipe i modded from a Savage and cut in down then tig welded it back together, worked like a charm short and fat gave the 21 a new lease of life as you can see by the pic below the size difference from the original pipe.
Great product the Fantom steel pipe and the sound and little more performance was noticeable.