I like it when someone tries to be different
![Smile :)](./images/smilies/icon_e_smile.gif)
Got a pic of your setup? At a guess
it could be that there is enough air/fuel mix in the tubing between the turbo and the
combustion chambers to cause the engine to flare even after you close the throttle.
Probably depends on the size of your turbo. If it is small and spools early it could be
making a few psi of boost at 2000rpm. Bearing in mind that I don't know anything
about turbo systems... is it possible that you need a vacuum operated bypass valve
to route that compressed charge backto the intake side of the compressor when the
throttle closes?
Cheers... jondee86