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Old 06-08-2009, 03:13 PM   #26 (permalink)
wstar
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Quote:
Originally Posted by Modshack View Post
Built some experimental big ID MAF tubes today, so the whole project should be interesting..Cool air and more of it!
You're probably more aware than I am, but just in case: beware larger MAF tubes giving false MAF readings. The stock MAF sensors are calibrated for a given tube diameter, and they will read artificially low airflow numbers in a larger tube (which results in the engine running lean and not realizing it, because the MAF input is wrong).

I think the wideband O2's in our headers will correct for this at idle/normal engine speeds, but maybe not at WOT. It may be moot anyways if our ECU's ability to predict knock and adjust timing in both directions is as good as some are claiming (e.g. in the threads about the engine adapting to higher octane fuel - in theory this is like an artificial boost in air density that the ECU can't directly see, which is a lot like dropping the fuel octane from a knock-avoidance point of view).

I don't really know anything definitive about this whole subject on our cars, but based on previous experience (LS1's from circa 10 years ago), you don't want to lie to the ECU about the MAF data, which is what a wider tube with stock sensor effectively does.
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