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Discussion Starter · #1 ·
Hers the deal, my scan tool doesnt read the MAF in voltage it reads it in LBS/Min. Can anyone tell me if my MAF readings are ok? I usually get around 56-58 Lbs/Min under WOT. Can Anyone help convert that or help out? Thanks Jamie
 

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L&M Engines
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03Venom

57 lb/min = 750 scfm
If the MAF is calibrated correctly that would be for 4.6L engine =
100% VE 750 scfm/.0813=9223RPM naturally aspirated.

If supercharged, a much lower RPM.

I neeed to know at what RPM you arrive at this reading of 57 lb/min

Regards. //Michael
 

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Discussion Starter · #3 ·
I Hit this at WOT around 5000 +/- 500 rpms. It does it every time i have logged it! Think im over running the MAF?
 

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Snake Charmer
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I would also like to find a way to see if we are pegging our MAFs by using the autotap, either via air flow or voltage.
 

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Well 57 lb/min at 5000 RPM is right for 185% combined VE. That would calculate to be approxmately 12 psi of boost corrected to STD atmosphere, NOT GUAGE PRESSURE IN THE CAR. Guage pressure is a function of the heated air from blower inefficiency and intercooler effectiveness. The higher you spin the blower the higher the inefficiency, power gain is much less and dash bord guage pressure gets higher.

With a correctly calibrated MAF voltage/mass air are directly related. With voltage output from a MAF calibrated it should be .5-4.90 volts from below idle to slightly past WOT peak rpm.

As an example idle 500 RPM 3 lb/min = .500 v, WOT 7000 RPM 80 lb/min = 4.8 v

I hope this helps.

For more in car tuning help with this see Joe at JD's Performance 215-938-9270 or post to his forum here.

//Michael

TORCO RACE FUEL DISTRIBUTOR
 

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Can you translate in english so dumb people like me get it

i.e. how much cfm is the 03 cobra maf limited to without having to flex any math skills. Its nice to know the voltages but id like to know the cfm limit before its pegged.
 

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Discussion Starter · #7 ·
What Jonas said lol! So, am i maxing the MAF out? Im running around 15-16 psi! And after logging it this morning it pegs 56-58 lbs/min as soon as it goes WOT. Thanks for your help. Jamie
 

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Jamie,

I don't have the parameters of a stock '03 MAF, but Monday I will have them for you.

Please e-mail me if I forget. I will post the answer here. //Michael


TORCO Race Fuels Distributor
 

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I Forgot, you say it shows 57 lb/min @ 5000 RPM. What speed due you typically run the engine to? Is there an increase in MAF readings?
If not the MAF is not calibrated correctly. //Michael
 

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Snake Charmer
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I just downloaded autotap 2.04 (my old release was 2.03) and the new release shows MAF voltage.
 
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