I made the venturi and needle valve assembly on mine. The needle is a 2-56 threaded rod with a taper I just ground on a sanding belt. It was stainless steel, so I could not solder it, so I had to butt nuts to keep the big washer on. There is a control line venturi available though, as a friend has one. I believe the needle assembly from the RC one threads into it. It is above the casting though, not like mine. I can not speak for Annette, but mine goes fairly fast with the thin wing. It kind of mushes around on loops, which is because of the wing being, well, a real estate sign. I have since cut the wing much smaller. It was traced from an F2D combat wing, but now is more like a Lil Satan. Still flies about the same. I have added a pic of the modified muffler, and a header I made for using a pipe. The muffler stinger can be unscrewed which opens it up to about 5 mm. It is a 6mm thread. I tapped it to 5/16" -32 or something and made a new stinger. I have also tried a turbo plug head which I made up. It helps about 1,500 rpm.