Apologies to resurrect such an old thread, but I'm planning on sending my throttles to Garage Ito for the 49mm enlargement, but I'm having difficulty finding out how to perfectly machine the plenum runner diameters to match.
LaurelPWR how did you go about CNC machining yours, did you have to get a jig made up for it to keep it straight and true? And just to clarify, is it a gradual taper from the 46mm to 49mm? i.e. it increases bit by bit from 46mm until it become 49mm at the throttle end.
Starting the taper from halfway, what kind of distance is that from the throttle end?
Apologies for the many questions, would be incredibly grateful for any info.