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has anyone done any logs to how much g/s airflow they reached through their MAF?

i went out lastnight and reached 160 g/s, mine is totally stock bar a CAF

i read you can work out rough bhp from this by deviding by 0.8 but this would be very low, does this only work with turbo cars?

that is only 1 bank...

8000 rev/min / 60 sec/min x 1/2 (intake cycle/rev) x 4.2 liter x 1.2 gm/liter (varies with temp/atm P/humid) ~ 336 g/sec for the whole engine or 168 for 1 bank...

this assumes a vol eff of 1 (it is usually a bit higher 1.02 or so) and assumes 8000 rpm

what RPM? temperature? humid? atm P and altitude...

160 sounds like a good number and using your factor ~ 160 / 0.8 x 2 banks ~ 400 HP

I have a P/P IM and in cold weather (40f and below) The best MAF I logged was 172g/s (recent carbon clean).

Weather conditions (as Arthur states above) dictate a lot, in 60F+ weather I see 150-155g/s.

I know you have CAF, is the IM also p/p? Minimal gains but every little helps in the end.

If I remember correctly the APR Stage III makes 235 g/s.

If I remember correctly the APR Stage III makes 235 g/s.

Pre port polish the best I recorded mine peaked at 158 and that was on a 85k mile car, standard with BMC filter approx. 20 degrees C. Post port polish best it peaked at is 165, slightly higher air temp.

I had 158 g/sec @ 7680 rpm.

That was stock, unfortunatly didnt make it to the red line. 4th gear, cant remember the temp. It was one evening in April, say 8 deg.

I will do another log shortly. Having fitted a BMC filer, Milltek cat-back. Also new plugs but doubt that will make a difference. Infact i doubt i will see much difference from the mods done. Maybe a little.

Temperature does make a big difference.

For the same volumetric flow: 160 g/sec @ 5 deg C = 149 g/sec @ 25 deg C.
So running at 5 deg rather than 25 deg should give 7.2% more mass flow.

284g/s per bank so far

241.78 7240 250.17 99.6 25
241.93 7320 253.44 99.6 24.5
242.08 7400 257.47 99.6 24.5
242.24 7440 261.53 99.6 24.5
242.38 7520 263.83 99.6 24.5
242.53 7600 267.39 99.6 24.5
242.67 7640 269.08 99.6 24.5
242.84 7720 272.72 99.6 24.5
242.99 7760 275.56 99.6 24.5
243.12 7800 277.92 99.6 24.5
243.27 7880 279.28 99.6 24.5
243.44 7960 282.61 99.6 23
243.58 7960 284.44 99.6 22
243.73 8000 284.58 99.6 22

PES Kit with M112 supercharger airflow:

138.64 6800 209.61 99.6 21.8
139.02 6960 216 99.6 21.8
139.41 7120 221.08 99.6 21
139.8 7240 226.03 99.6 21
140.18 7360 232.28 99.6 21
140.57 7520 236.11 99.6 20.3
140.96 7640 238.56 99.6 20.3
141.36 7760 242.78 99.2 20.3
141.72 7880 246.72 99.2 18
142.12 7960 248.72 99.2 18

PES Kit with M90 kit:

51.52 7760 221 99.6 20.3
51.67 7760 221.86 99.6 19.5
51.82 7800 223.28 99.6 19.5
51.98 7800 223.75 99.6 19.5
52.14 7840 224.53 99.6 19.5
52.29 7840 224.83 99.6 19.5
52.46 7880 224.14 99.6 19.5
52.61 7920 225.72 99.2 19.5
52.77 7960 226.81 99.6 19.5
52.93 7960 228.17 99.6 19.5
53.08 7800 226.97 99.6 20.3
53.23 7800 225.56 99.6 19.5

The columns above are:

Timestamp RPM g/s %throttle timing

I gather the first one is the TTS Rotrex charger? If so, that is some power it is producing

284 / 0.8 x 2 banks = 710 = I want

Doug can you remember what mine was with the stage II manifold and GruppeM?

53.12 7920 182.67 99.6 30
53.28 7960 183.31 99.6 30.8
53.44 8000 184.17 99.2 30.8
53.59 8040 183.47 99.6 30.8
53.74 8080 185.69 99.6 30
53.91 8120 186.33 99.6 30
54.07 8160 184.58 99.6 30
54.22 8200 184.44 99.2 30
54.37 8240 185.69 99.2 29.3
54.54 8280 187.53 99.6 29.3