[darkpuppet]

sr20det,Feb 25 2005, 04:41 PM Wrote:i have no egr in the nissan....i was told by nissan that i would not need it if i was not driving my car in the winter...he said it wont make much difference....why the winter has the effect on it, thats what i dont know :blink:
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Quote:

EGR - Exhaust Gas Recirculation



Why would anyone want to dump exhaust back into the intake of a perfectly good engine?

Unfortunately, the internal combustion engine is not `perfectly good.' The modern multi-valve, high compression engine can create NOx (Nitrous Oxide) during the high temperature combustion process. NOx reacts with sunlight to create atmospheric problems such as smog and so comes into the category of 'not a good idea'.

EGR is considered a `metered intake leak' and was developed to reduce the combustion temperatures to below 2,500 degrees, the threshold where NOx is created. Not unlike putting a brick in your lavatory to lower the volume of water used, the EGR valve meters a readily available inert gas (actually exhaust gas which contains a lot of very inert Carbon Dioxide) into the combustion chamber to effectively reduce the volume. Smaller effective displacement means less fire, and less heat and thus lower temperatures, thereby controlling NOx emissions.

tis quicker to copy and paste someone else's work.. I need a pint