ORIGINAL: Recycled Flyer

...A Diesel, when properly warmed and in tune will over compress with any form of returning or 'positive push' wave as that wave will force gases back into the open exhaust port at the last moment. This has been confirmed by fliers who have diesel speed models - no pipe other than a straight length that gained perhaps 200 rpm has any benefit on a diesel.

Yet here we are with MVVS 2.5cc diesels running with a known power boosting pipe, in the correct rev range and yet suffering nothing from over compression.

This seems to tell me that if the MVVS pipe has a 'positive' wave then its effect is not felt back at the exhaust port.

At the moment, my head hurts thinking about this!