Interesting development

My IM throttle body has sheared off one of the retaining pins that hold the butterfly in place (I sure hope it went out through the engine). The shaft has a break at the pin hole on the back side of the plate. I don't have a BOV and I am running 5.5psi max.

My thoughts are that the throttle slamming shut could be trapping boost and, with a 2.5" diameter throttle plate, be applying 27 pounds (plus any pressure pulse) across the plate. Do you think this might be enough, over time, to fatigue the pins and flex the shaft to breaking? Has anyone else experienced this?

There's plenty of people who've had TB's break on them, it's not related to dual throttles though.

Thanks and you are right - further research led me to here http://forum.miata.net/vb/showthread...+throttle+body