Offroading Online Magazine Issue #20 | Page 39

ost Pressure Common Rail Diesel Engines have every part of the engine monitored and managed from the air going in to the exhaust going out. Even the turbo boost is electronically monitored and managed. The exhaust gases required to drive the turbo have been closely controlled by engine design including the flow of the exhaust system. Changing to a larger exhaust can have effects on the operation and boost level of the turbo. Some EFI Diesel engines can actually have the turbo ‘over boost’ because of the gas flow changes of upgrading the exhaust. This can be for ‘better or worse’ so it is best to record boost operation and levels before you install an exhaust to follow the effects. It’s advisable when choosing a tuning chip for your new Common Rail Diesel that you choose one that ‘does not’ adjust turbo boost as Common Rail Diesels already have more than enough turbo boost to cope with. Chips that adjust turbo boost are doing so too offset and hide heavy fuel load increases. Diesel chips that don’t adjust boost are ‘for most of us’ wanting reliable power gains as they are not adding excessive load to the engine. Remember most of us want longevity from our ‘tow vehicle’ not short term racing. Safe Driving Andrew Offroading Online Magazine  39