Idle air injestion, g/sec?

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skid542
Fifth Gear
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Joined: Fri Dec 26, 2003 6:37 am
Location: North Idaho

Idle air injestion, g/sec?

Post by skid542 »

I'm working on setting up some of the values in my fuel tune and I have some options for idle conditions. One of them is a MAF limit that limits the signal sent to the ECU. This is based off air intake at idle.

So, in gram/second, how much air do our motors roughly injest during idle?

Thank you.
Lee

93' SS, 5mt swapped, 182k, not stock...
96' N/A OBW 5sp, 212k, Couple mods... RIP
99' N/A OBW, 4eat, mostly stock.
wtdash
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Re: Idle air injestion, g/sec?

Post by wtdash »

Lee,
Found this on USMB, which states it shouldn't exceed 4.8 g/sec.....this is on a '97 EJ25, but I'd bet it's going to be very similar, since they use the same MAF system (albeit the JECs/AUTECS version).

GL,
Td
Turbo Subies:
'87 GL-10 Turbo - SOLD
'90 BJ EJ22T/DOHC & 5speed swap - SOLD
'04 FXT, Forged internals, VF39, STI TMIC, Cobb AP- SOLD
'93 Legacy SS - 5-speed, SOLD :-(
'02 WRX -SOLD
'96 BD-turbo'd-SOLD
'98 SF - NA-T
skid542
Fifth Gear
Posts: 2857
Joined: Fri Dec 26, 2003 6:37 am
Location: North Idaho

Re: Idle air injestion, g/sec?

Post by skid542 »

Todd, thanks for the reply.

4.8 g/sec seems really low to me. Maybe it isn't, but 4.8g is not much at all. I just want to be sure the value I put in is correct so I don't lean it way out at idle.

Any other inputs?
Lee

93' SS, 5mt swapped, 182k, not stock...
96' N/A OBW 5sp, 212k, Couple mods... RIP
99' N/A OBW, 4eat, mostly stock.
IronMonkeyL255
Fourth Gear
Posts: 1902
Joined: Sat Aug 09, 2003 5:02 pm
Location: Woodruff, SC

Re: Idle air injestion, g/sec?

Post by IronMonkeyL255 »

could always find the voltage from the MAF at idle on a stock-ish car and backtrack from there, couldn't you?
Disclaimer: If anything I post is inaccurate, please correct me. I do not wish to add to the misinformation floating around on the internet.

That being said, everything I post is accurate to the best of my knowledge.

Rio Red '91 Legacy SS
skid542
Fifth Gear
Posts: 2857
Joined: Fri Dec 26, 2003 6:37 am
Location: North Idaho

Re: Idle air injestion, g/sec?

Post by skid542 »

Well that's what I'm hoping someone can give me or they can plug in one of Vikash's tools and tell me what it says at idle :). I would do this myself except I've converted to a speed density system and no longer have a MAF.

But yes, if I had a voltage I could back out the injestion.
Lee

93' SS, 5mt swapped, 182k, not stock...
96' N/A OBW 5sp, 212k, Couple mods... RIP
99' N/A OBW, 4eat, mostly stock.
BSOD2600
Fourth Gear
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Joined: Tue Sep 12, 2006 6:49 am
Location: Seattle, WA

Re: Idle air injestion, g/sec?

Post by BSOD2600 »

According to RevScan (which I strongly suspect uses a calculated airflow based off the MAF voltage) from a 13 sample collection...

Idle (rpm) = 750 (avg = 752)
Airflow [JECS] (g/s) = 2.6 through 3.4 (avg = 2.72)
MAF [JECS] (volt) = 0.94 through 1.02 (avg = 0.98)

'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
skid542
Fifth Gear
Posts: 2857
Joined: Fri Dec 26, 2003 6:37 am
Location: North Idaho

Re: Idle air injestion, g/sec?

Post by skid542 »

^^^ Perfect!

That's exactly what I needed to know. Many thanks!
Lee

93' SS, 5mt swapped, 182k, not stock...
96' N/A OBW 5sp, 212k, Couple mods... RIP
99' N/A OBW, 4eat, mostly stock.
IronMonkeyL255
Fourth Gear
Posts: 1902
Joined: Sat Aug 09, 2003 5:02 pm
Location: Woodruff, SC

Re: Idle air injestion, g/sec?

Post by IronMonkeyL255 »

Ya beat me to it.

I was about to go plug in my evoscan to grab it........
Disclaimer: If anything I post is inaccurate, please correct me. I do not wish to add to the misinformation floating around on the internet.

That being said, everything I post is accurate to the best of my knowledge.

Rio Red '91 Legacy SS
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