wicked-irocz

I posted a post earlier https://www.thirdgen.org/forums/tpi/...-tpi-flow.html about what I knew and what I was trying to find and no-one could tell me flow data for the stock camaro air box so I flowed it myself. Heres the data

What I knew before
-a stock head at .442" of lift (1.6 rockers) flows 190 cfm @ 28"
-a stock head at .415" of lift (1.5 rockers) flows 187 cfm @ 28"
-a stock runner flows 203 cfm @ 28"
-a stock base and runner flows 199 cfm @ 28"
-a stock MAF flows 529 cfm @ 28"
-a MAF with no screens flows 711 cfm @ 28"
-a stock TB flows 668 cfm @ 28"
-a stock TB with air foil flows 709 cfm @ 28"

What I found (in order of best flowing to least)
-The adapter I used flowed 677 cfm @ 28"
-V6 Lid with a V8 MAF w/o screens flowed 581 cfm @ 28"
-V6 Lid, V8 MAF w/o screens, Base w/o Baffles, Top of Center Ridge Cut Out,
K&N lengthwise flowed 562 cfm @ 28"
-V6 Lid, V8 MAF w/o screens, Base w/o Baffles, Top of Center Ridge Cut Out,
K&N widthwise flowed 560 cfm @ 28"
-V6 Lid, V8 MAF w/o screens, Base w/o Baffles, K&N flowed 558 cfm @ 28"
-V8 Lid and MAF flowed 535 cfm @ 28"
-V6 Lid and V8 MAF flowed 512 cfm @ 28"
-V8 Lid, V8 MAF, Base w/o Baffles, K&N flowed 511 cfm @ 28"
-V6 Lid, V8 MAF, Base w/o Baffles, K&N flowed 502 cfm @ 28"
-V6 Lid, V8 MAF, Base w/o Baffles, Fram flowed 470 cfm @ 28"
-V6 Lid, V8 MAF, Stock Base, Fram flowed 444 cfm @ 28"


What you can see is the fram filters choke the breathing to 470 cfm but as soon as you drop the K&Ns in it flows 32 cfm more with no other changes. Another interesting thing is the variance in the 2 lids. Im guessing it is just manufacturing differences as the sensor in the V6 lid should not cause that much less air flow. Notice how the V8 lid actually made the screened MAF flow more due to less turbulance? Then there was 2 cfm difference just by turning the filters. Also, cutting a 6"x3/4" hole under each one of the filters increased flow by 2 cfm indicating the filters/lid are likely the cause for restriction at that point so everyone that completely guts the base is gaining very little unless they have better than K&N filters and have modified the lid.

I will run a descreened MAF with the V6 lid, base with the baffles removed and tops of the center ridges cut out, K&Ns lengthwise setup for now. Just remember the stock throttle body with air foil flows 147 cfm more than a gutted airbox, K&N, descreened MAF combo.

If anyone has flow data for the plenum attached to the runners and base I would really like to see it. The flowing was done on a superflow 1020 flowbench.

92BLKL98

My Z is a Speed Density car I wonder what the V8 lid alone flows with K&N's and gutted airbox.

wicked-irocz

The V8 lid alone is going to flow a little better than the V8 MAF w/o screens, V6 Lid combo but not much. I would say no more than 600 cfm.

The V8 lid with a gutted base and K&Ns will flow a little better than the cut w/o baffles base, K&N, V6 lid, descreened MAF combo I posted. For that combo I would say no more than 580 cfm.

I can say this because the MAF w/o screens flows 711 cfm and that will obviously be very little, if any, restriction so the only real change would be the V6 to V8 lid.

rushtk

for those of us that are Lid ignorant..... what and where is it? Are you talking about the plastic housing over the filters? From reading your write up and let me say thank you very much for doing so, on the 92 Z 5.7 we should cut the 6" hole below each filter and switch to the K&N filters to get the best air flow. I see some with C.A.I and wonder how much more they are getting? Thank you again for the write up.

BadSS

Yes, the lid is the top part of the air box assembly covering the filters.

Orr recently posted that a homemade ram air set up and stock MAF ran the same times as a custom 3.5" CAI set up with a larger MAF and the filter sitting off in the fender wells.

There are a few that have modified the lid and claim increases. I never modified one myself, but would think it should be helpful on some of the more powerful 3rd gens still using the stock lid assembly.
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Here's a link to the modified lid that I had bookmarked
https://www.thirdgen.org/forums/tpi/...ied-there.html

This one has some pictures of "gutting" the air box that might prove helpful if you go that route.
https://www.thirdgen.org/forums/tpi/...ir-filter.html