RE: exhaust bubble..? and whistling noise UPDATE
the traxxas tuned pipe workes too. [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXSP47&P=ML]pipe[/link] it works great. i run it. my friend gave it to me... after he took the blue coloring off... and drilling a hole in the end.