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Are MAF g/sec readings a good indicator of airflow efficiency?

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Old 01-23-2016 | 09:12 PM
  #21  
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OLD THREAD ALERT

Was going to make the same thread and found this the other day. I want to know the answer to this (title of thread) and want to know everyones MAF readings during idle and WOT. Seems the thread was derailed before the OP got a proper answer to his qn.
What I've gathered from this thread is that 240 g/sec or so is too low for WOT
and this thread
https://ls1tech.com/forums/pcm-diagn...flow-idle.html
shows that idle should be around 7 g/s.

So idle should be 7 g/s and WOT around 400-1,500 or so???
Mine seems to bounce all over the place from 0 to 9,000 G/s but I see it at around 1,100 G/s half of the time on idle. Does that sound right at all for a modified/larger intake system?
My Mass Airflow Frequency usually sits on around 2,600Hz (and doesn't bounce around as hard).

I'm hoping that my high numbers indicate that my intake system is very umm non-restrictive, and that it's not a(nother) problem with my scantool.
Old 01-23-2016 | 10:43 PM
  #22  
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Depending on idle speed, g/sec would generally range from 7 to 13 g/sec. 1100 g/sec is a **** ton of air. That's like 2.5 pounds of air per second, which would be like 2000 ish cubic feet per minute.

2600 hz on your MAF should be near 10-g/sec give or take.

If the frequency is stable and g/sec is everywhere, it's probably another scanner set up parameter.
Old 01-24-2016 | 02:30 PM
  #23  
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G/sec is also going to vary with mods and a lot of other factors so imo thats sort of a poor way to measure the maf efficiency. Log KPA at wot, 101kpa is atmospheric and represents 0 restriction. Anything less than 98kpa or so is going to indicate some type of restriction. At that point it could be the intake or maf but its not too hard to figure out which at that point.
Old 01-25-2016 | 08:53 AM
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Thanks guys. You're a good dude, Lord V8r. I don't care what anyone (in the universe) says.

Still interested to know other guys MAF readings (G's and frequencies.. and now kPa) during idle and WOT and know their mods..
Old 01-25-2016 | 09:25 AM
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I log mine in lbs/min but it's around 1.2 lbs/min at idle and 52-54 lbs/min at WOT if I remember correctly.

My MAP readings are usually within 1-2 kPa of whatever the MAP reads with ignition on, engine off.

ls2 with 234/242 equivalent cam
ported 799/243 heads
Fast 90mm
4" intake piping and giant cone filter
1 3/4" longtubes and 3" duals
GM 85mm truck MAF




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