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boost psi vs map kpa reading

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Old Jul 7, 2010 | 08:30 PM
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Default boost psi vs map kpa reading

has anyone ever experienced there map kpa ,when logged with efi live or something like it, to be different, way different than what the boost gauge shows? and that is with the GM 2 bar map (BARO) from the cobalt i think but it is the correct one to use.
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Old Jul 7, 2010 | 09:07 PM
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What do you mean? Anything about 105(i think) kpa is considered boost. What are your logs showing?
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Old Jul 7, 2010 | 09:15 PM
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remember that 105 KPA = 0

above that is positive pressure
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Old Jul 7, 2010 | 09:17 PM
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BOOST kPa PSI
0 101.325 14.7
1 108.21969 15.7
2 115.11438 16.7
3 122.00907 17.7
4 128.90376 18.7
5 135.79845 19.7
6 142.69314 20.7
7 149.58783 21.7
8 156.48252 22.7
9 163.37721 23.7
10 170.2719 24.7
11 177.16659 25.7
12 184.06128 26.7
13 190.95597 27.7
14 197.85066 28.7
15 204.74535 29.7
16 211.64004 30.7
17 218.53473 31.7
18 225.42942 32.7
19 232.32411 33.7
20 239.2188 34.7
21 246.11349 35.7
22 253.00818 36.7
23 259.90287 37.7
24 266.79756 38.7
25 273.69225 39.7
26 280.58694 40.7
27 287.48163 41.7
28 294.37632 42.7
29 301.27101 43.7
30 308.1657 44.7
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Old Jul 8, 2010 | 04:12 PM
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so when data logging with efi live at an idle what will the kpa reading be? bc 0 kpa is = to 0 psi right?
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Old Jul 8, 2010 | 04:16 PM
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should be like 30-40 kpa if I remember right.
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Old Jul 8, 2010 | 05:34 PM
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Originally Posted by BADBOB
so when data logging with efi live at an idle what will the kpa reading be? bc 0 kpa is = to 0 psi right?
depends on your cam. 40-70 kpa. 0-100 is vacuum (no boost). Mine idles around 50-55 kpa and vacuum on the gage reads 15-16.
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Old Jul 8, 2010 | 06:30 PM
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so i guess that kpa conversion would be accurate as long as your map is scaled correctly??

we had trouble scalling it correctly
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Old Jul 8, 2010 | 07:15 PM
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Just remember that vacuum is in Hg not PSI. So the conversion formula is different.
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