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Old 08-28-2008, 04:25 AM   #21 (permalink)
instarx
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Join Date: Jul 2008
Location: NC
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Volvo - '00 Volvo V70 XC AWD SE
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Quote:
Originally Posted by tasdrouille View Post
You don't smoke because you don't have a turbo, you smoke because you are dumping too much fuel in for the air you can get. I had a 1990 NA diesel and it wasn't smoking at all at full load. I can get my 1999 TDI to smoke like an old freight train if I want by offsetting the base inj qty. Most of the time, if your stock diesel is smoking it just means your intake is restricted for the power you're trying to make. On TDIs it's often filling with gunk from the mix of EGR soot and oil from the crankcase so it'll smoke at high loads.
It's six of one/half dozen of another whether we say smoking is caused by not enough O2 or too much fuel. The result is the same - incomplete combustion resulting in black exhaust smoke. I'm sticking to my main point that turbos reduce that problem. If I implied that a lack of a turbo caused smoking I apologize.

But you are right, my post was worded badly. When I re-read it I see I gave the impression that no NA engine at full throttle ever got enough O2 and that all NA diesels belched black smoke - neither of which is correct. In fact, I have a 95 NA diesel that doesn't visibly smoke under full throttle.

However, having said that, all diesels smoke under load. It just isn't easily seen in daylight with the naked eye.


Last edited by instarx; 08-28-2008 at 05:38 AM..
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