Thursday, Oct 21, 2004 at 15:23
Can't quite agree with your standard equation, Chris. Boost level is not directly a factor in the smoke equation. It's more a case of "too much fuel for the available air = smoke" But even that's a bit too simplistic because, of course, timing, injection pressure and injector condition also come into it.
But assuming nothing else changed when the 'tuning' was done (i.e. his injectors didn't suddenly deteriorate the same day), I'd say it's a fair bet the off-boost/low boost maximum fuel rate has been set too high. This may give you slightly improved 'launch' from standstill but at the expense of objectionable smoke. (And, as
well as being a waste of fuel and causing further unnecessary anti-4WD feeling from other road users (who may be choking on it!), excessive smoke means excessive soot in the cylinders and earlier fouling of the engine oil with soot and unburned hydrocarbons.)
I agree the first step should be to return it to the workshop and tell them you're not happy with the results.
Chris, re."fueled up with higher boost and fuel", I'm just trying to make the point that the same % of excessive fuel will cause just as much smoke at standard boost, as it will at a higher boost. It's the mass ratio of available air to fuel at full throttle that matters.
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