Exactly why I want stiffer springs. I have done some checking to see where the threshold is on the slipper but it seems to be a decent amount higher than the engine braking. The engine braking on this nikenis fairly weak. I read because the Euro 5 emmisions strategy doesn't close the throttle plates very tight on decel. Something a real tune could no doubt fix but the springs would need to be stout enough to deal with it.