Airfoils/MAF Screens and Inj. flow rates
Forum: C4 HVAC, Fuel, Emissions, and Exhaust
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http://www.gmtuners.com/flow/index.htm
96LT1 2010-03-06 08:39:59
Found this online---these guys do ECM/PCM tuning---the tests are from a independent source (college)
I found it a very interesting and in my case suprising read...

Vaughn
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You are right, they are some interesting numbers. I've always been reluctant to remove MAF screens, but may have to rethink that decision. Thanks for posting.
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
I removed the screens from my '85 years ago. As long as the air filter is clean, and the air box is well sealed, a screen-less MAF sensor is fine.

Joel Adams
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So I guess the Airfoil is a good investment. I have heard so much feedback that they are a gimmick and a waste of money. Also the MAF screens, have seen this debate back on forth, I will take the plunge and remove them from 1989
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The screen is to straighten the air flow more than keep bugs off the MAF to improve the accuracy, particularly at low flow. It's hot enough to burn most dust that gets by the filter anyway. I'm running a Granatelli which comes without the screen and the output signal curve is calibrated for it. Also, there is a new digital MAF that you can find on Summit's web site. (on my wish list)
Notice they didn't post the differential across the throttle bodies or MAF's only that the density was adjusted to sea level. As I remember, carbs are generally rated at 4" Wg which is sort of where they'd run at wide open throttle on the street. So the numbers are only relative assuming they use the same base line differential pressure. Most air filters will create more drop than that so it's arbitrary at best. I've seen some hot rod articles that suggest a lot more than 10 HP remains in the induction inlet restriction.

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My 85 already had an air foil in it. took the screens out of the bosch MAF added K&N airfilter and cut the center out of my breather cover over the filter to which they sell online for one hundred dollars took me fifteen minutes cost one cut off wheel and have noticed a big difference mostly when getting in to it. of course 85 was before ODBII but have not had any codes or lights come once since doing so and service light before would come on once a week before. Love My Vette!
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Gotta watch using a K&N filter with a MAF sensor..if you get too much oil on the filter, it will mess up the signal from the MAF. Can cause several driveability issues if that happens. It can happen too just installing a fresh, properly oiled filter, if the filter is put into use to quickly. GM has had several TSBs out on this issue, as have all the other car makers.

Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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I have seen that TSB. but have never had any issues just have to follow the instructions on filter kit. the issues are with too much oil being used but thanks for the reminder.
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in Forum: C4 HVAC, Fuel, Emissions, and Exhaust
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